Publications
| Title: | Optimal locations and times for in situ methane measurements in Gale crater based on atmospheric transport |
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| Authors: | Xing, Guixin; Luo, Yangcheng; Mischna, Michael A.; Yung, Yuk L. |
| Affiliation: | AA(School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China), AB(Laboratoire de Météorologie Dynamique/Institut Pierre-Simon Laplace, Sorbonne Université, École Normale Supérieure, Université Paris Sciences et Lettres, École Polytechnique, Institut Polytechnique de Paris, Centre National de la Recherche Scientifique, Paris 75005, France), AC(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91011, USA), AD(Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA) |
| Journal: | Icarus, Volume 459, id.117214. |
| Publication Date: | Nov 2026 |
| Origin: | Elsevier BV |
| Keywords: | Planetary atmospheres, Atmospheric composition, Mars, Methane |
| Abstract Copyright: | © 2026 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies. |
| DOI: | https://doi.org/10.1016/j.icarus.2026.117214 |
| Bibliographic Code: | 2026Icar..45917214X |
| Abstract: | The detectability of surface-emitted methane on Mars by in situ measurements is highly dependent on atmospheric transport processes, which vary diurnally and seasonally and are modulated by local topography. Given the ongoing debate over methane on Mars, optimizing observing strategies can increase the likelihood of detecting methane signals, if methane is present, or maximize the scientific value of non-detections, thereby helping to constrain whether methane exists in the Martian atmosphere and, if so, its spatiotemporal behavior. Here, we develop a general framework based on inverse Lagrangian transport modeling to quantify methane detectability within Gale crater as a function of measurement location, local time, and season, without prior knowledge of the emission source. Applying this framework along the Curiosity rover's traverse reveals a shift in optimal measurement timing, from early morning during the initial phase of the traverse to midday after the rover ascended the slopes of Aeolis Mons. Expanding the analysis to the entire crater, we find that from midnight and early morning, methane detectability is maximized on low-lying crater floors, but daytime detectability increases with surface elevation. Seasonally and diurnally averaged maps identify the low-lying regions of Gale crater as the most favorable locations overall for detecting surface-emitted trace gases. If methane emissions are confined to daytime by barometric pumping, detectability would peak near dusk. This study provides a transferable atmospheric-transport framework for planning in situ measurements of trace gases on Mars and other planetary bodies with cratered terrains. |
| Title: | The effect of thermo-tidal winds on the expansion of local and regional dust storms on Mars |
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| Authors: | Toigo, Anthony D.; Richardson, Mark I.; Wang, Huiqun |
| Affiliation: | AA(Johns Hopkins University Applied Physics Laboratory, USA), AB(Aeolis Research, USA), AC(Smithsonian Astrophysical Observatory, Harvard-Smithsonian Center for Astrophysics, USA) |
| Journal: | Icarus, Volume 450, id.116975. |
| Publication Date: | May 2026 |
| Origin: | Elsevier BV |
| Abstract Copyright: | © 2026 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies. |
| DOI: | https://doi.org/10.1016/j.icarus.2026.116975 |
| Bibliographic Code: | 2026Icar..45016975T |
| Abstract: | Recent imaging observations from the Emirates Exploration Imager show significant diurnal variation of dust storm evolution that is unresolved by traditional daily global mapping from sun synchronous orbit. Motivated by these observations, we present initial simulations from a global numerical model examining the diurnal evolution of transported, radiatively active dust from simulated dust sources. The simulations show that the expansion and mixing of large local and regional dust storms are strongly modified by the wide diurnal "reach" of thermo-tidal winds. In particular, thermo-tidal winds can rapidly spread dust between adjacent storms and can translate storms over significant distances, including transporting storm dust between different meteorological regimes. |
| Title: | Bilayered Martian Polar CO<SUB>2</SUB> Snow Generation |
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| Authors: | Toigo, Anthony D.; Waugh, Darryn W.; Guzewich, Scott; Wang, Huiqun |
| Affiliation: | AA(Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA), AB(Johns Hopkins University, Baltimore, MD 21218, USA), AC(NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA), AD(Harvard Smithsonian Astrophysical Observatory, Cambridge, MA 02138, USA) |
| Journal: | The Planetary Science Journal, Volume 7, Issue 5, id.115, 14 pp. |
| Publication Date: | May 2026 |
| Origin: | American Astronomical Society |
| Keywords: | Mars, Atmospheric dynamics, Planetary atmospheres, Atmospheric science, Atmospheric circulation, Planetary polar regions, Polar caps, 1007, 2300, 1244, 116, 112, 1251, 1273 |
| Abstract Copyright: | © 2026. The Author(s). Published by the American Astronomical Society. |
| DOI: | https://doi.org/10.3847/PSJ/ae63c0 |
| Bibliographic Code: | 2026PSJ.....7..115T |
| Abstract: | The exchange of CO<SUB>2</SUB> between the atmosphere and the polar ice caps is a fundamental process on Mars, for both present-day and past climates, affecting the dynamics of the atmosphere and other surface─atmosphere interactions across the globe. Recent observations have shown multiple spatial-temporal variations in the atmosphere─surface CO<SUB>2</SUB> exchange in polar regions, including seasonal and interannual, longitudinal, and hemispheric variations. The causes of these variations remain uncertain. We examine the spatial-temporal variations of snow generation, and their connections to dynamical processes, using Mars Weather Research and Forecasting model simulations. The simulations indicate that there are two separable vertical layers of CO<SUB>2</SUB> snow formation: a thin near-surface layer and a broader upper layer between 300 and 10 Pa. The snow generation in the upper layer is confined to high latitudes and occurs in subregions within the cold areas inside the polar vortex, whereas the near-surface snow is generated further equatorward and extends as far as the seasonal snow cap. While the two separate layers are directly connected to different dynamical processes (baroclinic waves in the near-surface layer and polar vortex dynamics in the upper layer), there are indicators of coupling between the layers. The same waves appear in both layers, with strong lag correlations, and the two layers are associated with the thermally indirect Ferrel cell poleward of the winter polar vortex edge. |
| Title: | Impacts of Carbon Dioxide Deposition on Martian Near-Surface Wave Activity |
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| Authors: | Fok, Hung Kwan; Toigo, Anthony; Waugh, Darryn |
| Affiliation: | AA(Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD, USA;), AB(Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA), AC(Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD, USA;) |
| Journal: | Geophysical Research Letters, Volume 53, Issue 7, id.e2025GL120588, 9 pp. |
| Publication Date: | Apr 2026 |
| Origin: | American Geophysical Union (AGU) |
| Abstract Copyright: | © 2026. The Author(s). |
| DOI: | https://doi.org/10.1029/2025GL120588 |
| Bibliographic Code: | 2026GeoRL..5320588F |
| Abstract: | A prominent feature of Mars' winter atmosphere is near-surface baroclinic wave activity. These waves exert strong control on dust storm variability and contribute to transport of heat, momentum, and dust. Using a suite of Mars general circulation model simulations, we investigate an underexplored connection between near-surface wave activity and another distinctive feature of Martian atmosphere: deposition of its primary constituent ${\text{CO}}_{2}$ in winter polar regions. We identify a two-fold impact: deposition of atmospheric ${\text{CO}}_{2}$ onto the surface extends the duration of high wave activity into spring, while latent heat release during ${\text{CO}}_{2}$ deposition suppresses wave activity during winter. Both effects arise from changes in the westerly jet structure. ${\text{CO}}_{2}$ deposition modifies the spatial and temporal structure of the jet, altering the baroclinic instability growth rate, and hence strength and timing of near-surface waves. Our study highlights the importance of considering ${\text{CO}}_{2}$ deposition in understanding Martian dust storms and atmospheric transport. |
| Title: | Atmospheric Dynamics of IR-Active Particles Released From Mars' Surface |
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| Authors: | Richardson, Mark I.; Ansari, Samaneh; Fan, Bowen; Ramirez, Ramses; Mohseni, Hooman; Mischna, Michael A.; Hecht, Michael H.; Steele, Liam J.; Sharipov, Felix; Kite, Edwin S. |
| Affiliation: | AA(Aeolis Research, Chandler, AZ, USA), AB(Northwestern University, Evanston, IL, USA), AC(University of Chicago, Chicago, IL, USA; Now at Yale University, New Haven, CT, USA;), AD(University of Central Florida, Orlando, FL, USA;), AE(Northwestern University, Evanston, IL, USA;), AF(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA;), AG(MIT Haystack Observatory, Westford, MA, USA;), AH(University of Chicago, Chicago, IL, USA; Now at European Center for Medium‐Range Weather Forecasts, Reading, UK), AI(Universidade Federal do Paraná, Curitiba, Brazil), AJ(University of Chicago, Chicago, IL, USA;) |
| Journal: | Geophysical Research Letters, Volume 53, Issue 6, id.e2025GL121051, 11 pp. |
| Publication Date: | Mar 2026 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Earth and Planetary Astrophysics, Geophysics |
| Abstract Copyright: | © 2026. The Author(s). |
| DOI: | https://doi.org/10.1029/2025GL121051 |
| Bibliographic Code: | 2026GeoRL..5321051R |
| Abstract: | Surface release of radiatively active particles, with high infrared- (IR-)to-visible extinction ratios, has been proposed as a method of warming Mars. However, to warm Mars using aerosols, particles released locally must disperse globally. Here we provide an initial reference study in a plume tracking, dry Martian atmospheric model to address this question. The winds that transport aerosols respond to the aerosol's IR forcing, implying strong radiative-dynamical feedbacks (RDF). We investigate RDF from surface release of two particle compositions: carbon (graphene) and metal (Al). Self-lofting helps particles rise and spread locally and regionally, and the Hadley cell strengthens under warming, aiding latitudinal mixing. Within our model, Mars RDF enable engineered-aerosol warming. Warming is slightly greater for three-dimensional vs. 1D-models and also depends on spectral resolution of radiative transfer. We assess implications for Mars warming. Many open atmospheric science questions remain, including the role of agglomeration, dry-deposition rate uncertainty, and modeling water cycle feedbacks. |
| Title: | Characteristics and dynamics of spring-time northern cap-edge dust activities simulated by a Mars climate model |
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| Authors: | Luo, Z. H.; Chow, K. C.; Xiao, J. |
| Affiliation: | AA(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau, PR China), AB(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau, PR China), AC(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau, PR China) |
| Journal: | Icarus, Volume 445, id.116843. |
| Publication Date: | Feb 2026 |
| Origin: | Elsevier BV |
| Keywords: | Mars, Cap-edge dust storm, Sublimation flow, Dust lifting |
| Abstract Copyright: | © 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies. |
| DOI: | https://doi.org/10.1016/j.icarus.2025.116843 |
| Bibliographic Code: | 2026Icar..44516843L |
| Abstract: | Northern cap-edge dust storms during spring are major dust activities in the non-dusty season of Mars. In this study, we apply a parameterization scheme to the Mars climate model MarsWRF to simulate the dust activities in the northern cap-edge region. Consistent with observations, the simulation result shows a period of weak dust activities in the northern mid spring (Ls 30°-60°) and a stronger period just before the northern summer solstice, with a pause of dust activities between these two periods. The results of the sensitivity experiments suggest that the sublimation flow associated with cap recession is important to the occurrence of dust lifting but its effect on dust lifting near the cap edge could be different in different periods. The sublimation flow generally reduces the dust lifting flux in mid spring while enhances dust lifting at the end of spring. Three specific areas that are prone to dust lifting have also been identified. The simulation results suggest that the locations of the preferred dust lifting areas and the pause between the two active periods are possibly related to the topography in northern high latitudes. |
| Title: | Seasonal Ice Cover Could Allow Liquid Lakes to Persist in a Cold Mars Paleoclimate |
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| Authors: | Moreland, Eleanor L.; Dee, Sylvia G.; Jiang, Yueyang; Bischof, Grace; Mischna, Michael A.; Hartigan, Nyla; Russell, James M.; Moores, John E.; Siebach, Kirsten L. |
| Affiliation: | AA(Department of Earth, Environmental, and Planetary Sciences, Rice University, Houston, TX, USA;), AB(Department of Earth, Environmental, and Planetary Sciences, Rice University, Houston, TX, USA;), AC(Department of Earth, Environmental, and Planetary Sciences, Rice University, Houston, TX, USA), AD(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA; Department of Earth and Space Science and Engineering, York University, North York, ON, Canada;), AE(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA;), AF(Department of Earth, Environmental, and Planetary Sciences, Rice University, Houston, TX, USA), AG(Department of Earth, Environmental, and Planetary Sciences, Brown University, Providence, RI, USA;), AH(Department of Earth and Space Science and Engineering, York University, North York, ON, Canada;), AI(Department of Earth, Environmental, and Planetary Sciences, Rice University, Houston, TX, USA;) |
| Journal: | AGU Advances, Volume 7, Issue 1, id.e2025AV001891, 19 pp. |
| Publication Date: | Feb 2026 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | lake dynamics, Mars, paleoclimate, hydrology, Curiosity rover, Gale crater |
| Abstract Copyright: | © 2025. The Author(s). |
| DOI: | https://doi.org/10.1029/2025AV001891 |
| Bibliographic Code: | 2026AGUA....701891M |
| Abstract: | Geomorphic and stratigraphic studies of Mars prove that extensive liquid water flowed and pooled on the surface early in Mars' history. Martian paleoclimate models, however, have difficulty simulating climate conditions warm enough to maintain liquid water on early Mars. Reconciling the geologic record and paleoclimatic simulations of Mars is critical to understanding Mars' early history, atmospheric conditions, and paleoclimate. This study uses an adapted lake energy balance model to investigate the connections between Martian geology and climate. The Lake Modeling on Mars for Atmospheric Reconstructions and Simulations (LakeM<SUP>2</SUP>ARS) model is modified from an Earth-based lake model to function in Martian conditions. We use LakeM<SUP>2</SUP>ARS to investigate the conditions necessary to simulate a lake in Gale crater. Working at a localized scale, we combine climate input from the Mars Weather Research & Forecasting general circulation model with geologic constraints from Curiosity rover observations to identify potential climatic conditions required to maintain a seasonally ice-free lake. Our results show that an initially small lake system (10 m deep) with ∼50 mm monthly water input and seasonal ice cover would retain seasonal liquid water for over 100 years, demonstrating conditions close to long-term lake survivability. These results are an important step in resolving the historic disconnect between climate and geology on Mars. Continued use and iteration of LakeM<SUP>2</SUP>ARS will strengthen connections between Mars' paleoclimate and geology to inform climate models and enhance our understanding of conditions on early Mars. |
| Title: | Impact of Titan's Polar Vortex on the Transport of Chemical Species |
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| Authors: | Shultis, J.; Waugh, D. W.; Toigo, A. D.; Lombardo, N. A.; Lora, J. M. |
| Affiliation: | AA(Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD, USA;), AB(Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD, USA;), AC(Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA), AD(Department of Earth and Planetary Sciences, Yale University, New Haven, CT, USA;), AE(Department of Earth and Planetary Sciences, Yale University, New Haven, CT, USA;) |
| Journal: | Journal of Geophysical Research: Planets, Volume 131, Issue 2, id.e2025JE009367, 16 pp. |
| Publication Date: | Feb 2026 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | polar vortex, titan, stratosphere, transport, atmosphere, tracers |
| Abstract Copyright: | © 2026. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2025JE009367 |
| Bibliographic Code: | 2026JGRE..13109367S |
| Abstract: | Distributions of trace hydrocarbons in the atmosphere of Titan possess a strong seasonality. In mid-winter, hydrocarbons are thought to be able to escape through the polar vortex and develop "tongues" of enriched air which spread equatorward from the poles. However, recent studies have shown that the mixing barrier associated with a polar vortex of similar structure to the ones found on Titan should still be strong enough to isolate these hydrocarbons. Here, we examine the horizontal mixing associated with the polar vortices throughout their lifetime by using simulations of passive chemical tracers and contour advection for two Titan-specific three-dimensional (3D) general circulation models. Our analysis reveals that during the fall, the mixing barrier associated with the vortex extends above ∼0.1 hPa and isolates the stratospheric polar regions, allowing for strong enrichment by mesospheric descent. During winter, however, the vertical extent of the polar vortex is reduced due to the winter weakening, opening a region directly above the polar vortex (∼1─0.1 hPa) where tracer-depleted air is transported poleward, locally reducing tracer concentrations in the upper stratosphere and creating an enriched tracer region below in the lower-mid stratosphere. The presence of an extremely broad mixing barrier within and below the polar vortex (>1 hPa) would highly limit the movement of material equatorward and may indicate that previous observations of hydrocarbon tongues on Titan may be due to the influx of material above the polar vortex rather than escape across the vortex; further work is needed to verify this theory. |
| Title: | Equatorial Waves Associated with Dust Storms as Simulated in a Mars General Circulation Model |
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| Authors: | Wang, Huiqun; Richardson, Mark I.; Toigo, Anthony D. |
| Affiliation: | AA(Smithsonian Astrophysical Observatory, Center for Astrophysics Harvard-Smithsonian, Cambridge, MA, USA), AB(Aeolis Research, Chandler, AZ, USA), AC(John Hopkins University Applied Physics Laboratory, Laurel, MD, USA) |
| Journal: | The Planetary Science Journal, Volume 7, Issue 1, id.1, 23 pp. |
| Publication Date: | Jan 2026 |
| Origin: | American Astronomical Society |
| Keywords: | Solar system terrestrial planets, Mars, Atmospheric dynamics, Atmospheric circulation, 797, 1007, 2300, 112 |
| Abstract Copyright: | © 2026. The Author(s). Published by the American Astronomical Society. |
| DOI: | https://doi.org/10.3847/PSJ/ae28d2 |
| Bibliographic Code: | 2026PSJ.....7....1W |
| Abstract: | Equatorial atmospheric waves provide a mechanism for variability on a wide range of timescales and for disturbances in one part of the tropics to influence other tropical locations around the globe. A Mars general circulation model is used to investigate how equatorial waves behave under different atmospheric dust loading scenarios and when perturbed by dust storms. Such waves may be important for understanding triggering of distant dust storms or additional dust lifting centers within large storms. Equatorial waves appear to change when dust storm sequences cross the equator or when background dust amounts significantly vary, with eastward- and westward-propagating waves within a wide spectral interval being amplified in general. Specifically, many low-frequency, long-wavelength equatorial waves become prominent during prescribed dust storm episodes. Their horizontal wave structures seen in the 100 Pa geopotential field show a resemblance to equatorial Rossby, Kelvin, and mixed Rossby─gravity waves. Waves with different wave periods and zonal wavenumbers evolve with time and interfere with each other, leading to complex time-dependent eddy patterns. This study shows that both dust storms and background dust can significantly influence the spectra and structures of eddies in the tropical Martian atmosphere. |
| Title: | The Feedback of Atmospheric Dust Tides on Migrating Thermal Tides During Martian Major Dust Storms: A Model Study Based on MarsWRF |
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| Authors: | Cheng, Yueming; Wu, Zhaopeng; Lian, Yuan; Cui, Jun; Wei, Yong |
| Affiliation: | AA(Planetary Environmental and Astrobiological Research Laboratory (PEARL), School of Atmospheric Sciences, Sun Yat‐Sen University, Zhuhai, China;), AB(Key Laboratory of Planetary Science and Frontier Technology, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China;), AC(Aeolis Research, Chandler, AZ, USA), AD(Planetary Environmental and Astrobiological Research Laboratory (PEARL), School of Atmospheric Sciences, Sun Yat‐Sen University, Zhuhai, China;), AE(Key Laboratory of Planetary Science and Frontier Technology, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China;) |
| Journal: | Journal of Geophysical Research: Planets, Volume 130, Issue 11, id.e2024JE008914, 24 pp. |
| Publication Date: | Nov 2025 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Martian atmosphere, GCM simulation, dust storm, tides |
| Abstract Copyright: | © 2025. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2024JE008914 |
| Bibliographic Code: | 2025JGRE..13008914C |
| Abstract: | Previous studies revealed intense diurnal variations in dust opacity in the southern hemisphere during major dust storms on Mars. This short-term dust variation is also referred to as 'dust tides' due to its violent north-south diurnal motion, which is driven by strong meridional tidal winds. Given the pivotal role of airborne dust in Martian climate, it is imperative to assess the dynamical impact of dust tides. This study focuses on the feedback between dust tides and atmospheric thermal tides on Mars during major dust storms, employing the MarsWRF General Circulation Model. In order to evaluate the impact of dust tides on atmospheric thermal tides, we compare two scenarios: "dust tide" and "no dust tide." The former accounts for diurnal dust variations, whereas the latter utilizes daily-averaged dust distributions. The results of our simulations indicate that the inclusion of diurnal dust variations leads to a notable increase in the amplitude of Martian atmospheric migrating diurnal and semidiurnal tides. The enhanced atmospheric diurnal tides can reinforce the diurnal dust variations through the increased meridional wind, thereby establishing a positive feedback mechanism. Sensitivity experiments, including both latitudinal amplitude variations and phase-shifted scenarios, demonstrate that Martian atmospheric diurnal tides respond linearly to the latitudinal extent of dust tides. Moreover, the feedback efficiency is strongly modulated by the local time of dust enhancement, with phase alignment between dust-induced heating and tidal oscillations being critical for effective amplification. These results imply that even modest latitudinal variations in dust opacity, if aligned with tidal oscillations, can be further amplified during major dust storms. These findings highlight the necessity of incorporating short-term dust variations in climate models to accurately predict Martian atmospheric behaviors during dust storms. |
| Title: | Rapid Decay of Martian Global Dust Storms Driven by Small-Scale Deposition Processes in the Lower Planetary Boundary Layer |
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| Authors: | Li, Lulu; Sun, Cong; Newman, Claire E.; Fan, Siteng; Zhao, Yongxuan; Li, Tao; Zhao, Chun |
| Affiliation: | AA(National Key Laboratory of Deep Space Exploration/School of Earth and Space Sciences/Institute of Advanced Interdisciplinary Research on High‐Performance Computing Systems and Software, University of Science and Technology of China, Hefei, China; Department of Earth and Space Sciences, Southern University of Science and Technology, Shenzhen, China;), AB(Department of Earth and Space Sciences, Southern University of Science and Technology, Shenzhen, China), AC(Aeolis Research, Chandler, AZ, USA;), AD(Department of Earth and Space Sciences, Southern University of Science and Technology, Shenzhen, China;), AE(National Key Laboratory of Deep Space Exploration/School of Earth and Space Sciences/Institute of Advanced Interdisciplinary Research on High‐Performance Computing Systems and Software, University of Science and Technology of China, Hefei, China), AF(National Key Laboratory of Deep Space Exploration/School of Earth and Space Sciences/Institute of Advanced Interdisciplinary Research on High‐Performance Computing Systems and Software, University of Science and Technology of China, Hefei, China;), AG(National Key Laboratory of Deep Space Exploration/School of Earth and Space Sciences/Institute of Advanced Interdisciplinary Research on High‐Performance Computing Systems and Software, University of Science and Technology of China, Hefei, China; Laoshan Laboratory, Qingdao, China; CAS Center for Excellence in Comparative Planetology, University of Science and Technology of China, Hefei, China;) |
| Journal: | Geophysical Research Letters, Volume 52, Issue 22, id.e2025GL118229, 10 pp. |
| Publication Date: | Nov 2025 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | MarsWRF, global dust storm, dry deposition, radiative-dynamic feedback |
| Abstract Copyright: | © 2025. The Author(s). |
| DOI: | https://doi.org/10.1029/2025GL118229 |
| Bibliographic Code: | 2025GeoRL..5218229L |
| Abstract: | As one of the iconic features on Mars, global dust storms (GDSs) often decay rapidly. However, general circulation models (GCMs) typically underestimate their decay rates, which is one of the major challenges in simulating the Martian atmosphere. Here, we evaluate the role of a recently implemented size-resolved microphysical deposition scheme of dust particles in the MarsWRF model on GDS evolution. This scheme includes a series of microphysical processes, in addition to gravitational sedimentation, which facilitates the efficient removal of small dust particles. The model successfully reproduces the observed increase in effective particle radius during dust storms, along with their rapid decay. A radiative-dynamic positive feedback loop is seen among solar insolation, atmospheric stability, dust lifting and dissipation, and atmospheric dynamics. These results highlight the role of microphysics in the development of planetary-scale events on Mars, and underscore the need to include small-scale processes in Mars GCMs. |
| Title: | The Radiative Effect of Dust on the Convective Boundary Layer of Mars |
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| Authors: | Zhang, Kun; Chow, Kim-Chiu; Zhou, Bowen; Xiao, Jing |
| Affiliation: | AA(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau, PR China;), AB(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau, PR China; CNSA Macau Center for Space Exploration and Science, Macau, PR China;), AC(Key Laboratory of Mesoscale Severe Weather/MOE and School of Atmospheric Sciences, Nanjing University, Nanjing, China;), AD(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau, PR China; CNSA Macau Center for Space Exploration and Science, Macau, PR China;) |
| Journal: | Journal of Geophysical Research: Planets, Volume 130, Issue 9, id.e2025JE009179, 20 pp. |
| Publication Date: | Sep 2025 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, dust, boundary layer, simulation, LES |
| Abstract Copyright: | © 2025. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2025JE009179 |
| Bibliographic Code: | 2025JGRE..13009179Z |
| Abstract: | Mars has an abundant amount of dust in its atmosphere that can have significant effects on the structure and dynamics of the Convective Boundary Layer (CBL). In this study, we employ a Large Eddy Simulation (LES) configuration of the Mars Weather Research and Forecasting (MarsWRF) model to investigate the radiative effects of dust on the Martian CBL. Our results reveal that while dust reduces the amount of solar radiation reaching the ground surface, it also absorbs and re-emits the radiation energy, leading to a warming effect in the CBL. We find that the increase in dust concentration may enhance turbulence near the top of the CBL while suppressing mixing in the lower layers. This process leads to the development of a deep but stable and stratified boundary layer, which turns out to affect the transport and distribution of dust. In addition, our results indicate that evaluating the boundary layer depth with the bulk Richardson number could be inappropriate in dusty conditions. The radiative heating of dust may reduce the vertical gradient in the Richardson number, so it is less effective to determine the true boundary layer height with the conventional threshold-based methods. |
| Title: | The role of planetary-scale waves on the stratospheric superrotation in Titan's atmosphere |
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| Authors: | Lian, Yuan; Leung, Cecilia; Newman, Claire; Tamppari, Leslie |
| Affiliation: | AA(Aeolis Research, Chandler, AZ, United States of America), AB(NASA JPL, Pasadena, CA, United States of America), AC(Aeolis Research, Chandler, AZ, United States of America), AD(NASA JPL, Pasadena, CA, United States of America) |
| Journal: | Icarus, Volume 435, id.116561. |
| Publication Date: | Jul 2025 |
| Origin: | Elsevier BV |
| Keywords: | Titan atmosphere, Planetary waves, Superrotation, Atmospheric instabilities, Wave analysis, Earth and Planetary Astrophysics, Atmospheric and Oceanic Physics |
| Abstract Copyright: | © 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies. |
| DOI: | https://doi.org/10.1016/j.icarus.2025.116561 |
| Bibliographic Code: | 2025Icar..43516561L |
| Abstract: | We analyze simulation results from the TitanWRF global circulation model to understand the mechanisms that maintain the equatorial superrotation in Titan's stratosphere. We find that the eddies associated with wave activities can transport angular momentum upgradient to zonal flow, leading to acceleration of the equatorial superrotation. The dominant wave modes identified in this study are consistent with previous studies, with zonal wavenumber 1 being the major contributor to the prograde acceleration. Despite the same conclusion of maintenance of equatorial superrotation via wave-mean interactions, we find that the way waves interact with the zonal flow in TitanWRF is slightly different from some other studies. We confirm our previous findings that in TitanWRF this occurs primarily during a dozen or so annual, short-duration (a few Titan sols) angular momentum "transfer events," which have a repeatable seasonal pattern but differ slightly in timing and magnitude between years. This is not the case in the Titan Atmosphere Model (TAM), which found milder angular momentum transfers that produced the strongest acceleration of superrotation around solstice in the upper stratosphere and more continuous year-around acceleration in the lower stratosphere. Despite differences in angular momentum transfer across models, we further find that, similar to the TAM wave analysis results, eddies generated by Rossby-Kelvin instabilities may be the major source of prograde angular momentum for the equatorial superrotation, although TitanWRF may also include contributions from the absorption of vertically propagating equatorial Kelvin waves. This differs from our previous work, which suggested barotropic waves were responsible for TitanWRF's solsticial transfer event. |
| Title: | Dust Lifting and Deposition Over Six Mars Years at Gale Crater, Mars, From REMS Observations and Mesoscale Simulations |
|---|---|
| Authors: | Vicente-Retortillo, A.; Martinez, G. M.; Newman, C. E.; Lemmon, M. T.; Johnson, J. R.; Mason, E. L.; Renno, N. O.; Rodriguez-Manfredi, J. A. |
| Affiliation: | AA(Centro de Astrobiologia (INTA-CSIC), Madrid, Spain;), AB(Centro de Astrobiologia (INTA-CSIC), Madrid, Spain;), AC(Aeolis Research, Chandler, AZ, USA;), AD(Space Science Institute, Boulder, CO, USA;), AE(Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA;), AF(Northern Arizona University, Flagstaff, AZ, USA), AG(University of Michigan, Ann Arbor, MI, USA), AH(Centro de Astrobiologia (INTA-CSIC), Madrid, Spain) |
| Journal: | Journal of Geophysical Research: Planets, Volume 130, Issue 6, id.e2024JE008888, 18 pp. |
| Publication Date: | Jun 2025 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, dust lifting, dust accumulation, Mars science laboratory, REMS, MarsWRF |
| Abstract Copyright: | © 2025. The Author(s). |
| DOI: | https://doi.org/10.1029/2024JE008888 |
| Bibliographic Code: | 2025JGRE..13008888V |
| Abstract: | We present the temporal evolution of the effect of dust accumulation on two surfaces of the Curiosity rover at Gale crater during almost 4,000 sols using Rover Environmental Monitoring Station (REMS), Chemcam and Mastcam observations, and compare it with simulations of the Mars Weather Research and Forecasting Model (MarsWRF) atmospheric numerical model and environmental observations to improve our understanding of dust lifting on Mars. After almost six full Mars Years (MY), dust accumulated on the REMS UV sensor (UVS) attenuates an average of 45% of the incoming radiation. Dust accumulation on the UVS follows a seasonal cycle with gradual dust accumulation during the aphelion season followed by dust removal until L<SUB>s</SUB> ∼ 300°. However, there is a strong interannual variability during the dusty season. MarsWRF simulations show that wind stress has a strong diurnal, seasonal and interannual variability; simulations of dust devil activity show a seasonal pattern that aligns with pressure drop observations, peaking also at L<SUB>s</SUB> ∼ 300°. Dust lifting mechanisms are variable, with a larger relative importance of wind stress in MY 31 and 32, and of dust devils in MY 34 to 36. Dust accumulation on the Chemcam calibration target follows a very similar temporal evolution, but with a marked offset since the 2018 Global Dust Storm, suggesting that surface tilt is particularly important around intense dust storms. We characterize dust lifting mechanisms at Gale crater and quantify the effect of dust accumulation during an extraordinary dust storm on different surfaces; the observed net removal periods validate MarsWRF simulations and suggest the suitability of Gale Crater for long-term solar-powered missions. |
| Title: | Impacts of Dry Deposition Processes With Resolved Dust Particle Sizes on Simulating the Martian Dust |
|---|---|
| Authors: | Li, Lulu; Zhao, Chun; Newman, Claire E.; Zhao, Yongxuan; Feng, Jiawang; Li, Tao; Yang, Chengyun; Yue, Yingxi |
| Affiliation: | AA(Deep Space Exploration Laboratory/School of Earth and Space Sciences, CMA-USTC Laboratory of Fengyun Remote Sensing, State Key Laboratory of Fire Science, Institute of Advanced Interdisciplinary Research on High-Performance Computing Systems and Software, University of Science and Technology of China, Hefei, China;), AB(Deep Space Exploration Laboratory/School of Earth and Space Sciences, CMA-USTC Laboratory of Fengyun Remote Sensing, State Key Laboratory of Fire Science, Institute of Advanced Interdisciplinary Research on High-Performance Computing Systems and Software, University of Science and Technology of China, Hefei, China; Laoshan Laboratory, Qingdao, China; CAS Center for Excellence in Comparative Planetology, University of Science and Technology of China, Hefei, China;), AC(Aeolis Research, Chandler, AZ, USA;), AD(Deep Space Exploration Laboratory/School of Earth and Space Sciences, CMA-USTC Laboratory of Fengyun Remote Sensing, State Key Laboratory of Fire Science, Institute of Advanced Interdisciplinary Research on High-Performance Computing Systems and Software, University of Science and Technology of China, Hefei, China), AE(Deep Space Exploration Laboratory/School of Earth and Space Sciences, CMA-USTC Laboratory of Fengyun Remote Sensing, State Key Laboratory of Fire Science, Institute of Advanced Interdisciplinary Research on High-Performance Computing Systems and Software, University of Science and Technology of China, Hefei, China;), AF(Deep Space Exploration Laboratory/School of Earth and Space Sciences, CMA-USTC Laboratory of Fengyun Remote Sensing, State Key Laboratory of Fire Science, Institute of Advanced Interdisciplinary Research on High-Performance Computing Systems and Software, University of Science and Technology of China, Hefei, China;), AG(Deep Space Exploration Laboratory/School of Earth and Space Sciences, CMA-USTC Laboratory of Fengyun Remote Sensing, State Key Laboratory of Fire Science, Institute of Advanced Interdisciplinary Research on High-Performance Computing Systems and Software, University of Science and Technology of China, Hefei, China;), AH(Deep Space Exploration Laboratory/School of Earth and Space Sciences, CMA-USTC Laboratory of Fengyun Remote Sensing, State Key Laboratory of Fire Science, Institute of Advanced Interdisciplinary Research on High-Performance Computing Systems and Software, University of Science and Technology of China, Hefei, China) |
| Journal: | Journal of Geophysical Research: Planets, Volume 130, Issue 5, id.e2024JE008616, 31 pp. |
| Publication Date: | May 2025 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | dry deposition, Martian dust, resolved particle sizes, MarsWRF |
| Abstract Copyright: | © 2025. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2024JE008616 |
| Bibliographic Code: | 2025JGRE..13008616L |
| Abstract: | Mars, characterized as a "desert" planet with little water vapor, primarily relies on dry deposition for dust removal. Although these processes include gravitational sedimentation, turbulent transfer, Brownian diffusion, impaction, interception, and rebound, most current models consider only gravitational sedimentation. To have a more comprehensive understanding of the effects of Martian dust removal processes, a physics-based scheme of dry deposition processes with resolved dust particle sizes is implemented in the Mars Weather Research and Forecasting (MarsWRF) model. Results show that the size-resolved dry deposition scheme significantly increases the dry deposition velocity, with the maximum difference (over 0.024 m/s) occurring at 0.884 μm size bin. This enhanced removal efficiency leads to an increase of 0.4 μm in the effective radius of airborne dust throughout the year and a reduction of approximately 0.09 in dust opacity, particularly in the northern high latitudes during autumn and winter, compared to the simulation that only considers a size-resolved gravitational sedimentation scheme. The overestimation of low-level atmospheric temperature in the mid-to-low latitudes, excluding near-surface regions between $20\mathit{{}^{\circ}}$ and $60\mathit{{}^{\circ}}$N, during ${L}_{s}=230-250\mathit{{}^{\circ}}$ (considered as peak-dust phase) is partially corrected, with a correction of up to 1 K compared to the single-particle size simulation and up to 5 K compared to the size-resolved sedimentation-only simulation, bringing it closer to MCS observations. Additionally, the size-resolved dry deposition simulation reduces the condensation rate of atmospheric CO<SUB>2</SUB> and the thickness of the northern CO<SUB>2</SUB> ice cap, aligning better with Viking Lander observations during northern winter and spring than the size-resolved sedimentation-only simulation. |
| Title: | Transport and Mixing in Planetary Polar Vortices with Annular and Monopolar Potential Vorticity Structures |
|---|---|
| Authors: | Shultis, Jacob; Seviour, William; Waugh, Darryn; Toigo, Anthony |
| Affiliation: | AA(Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21210, USA), AB(Global Systems Institute and Department of Mathematics and Statistics, University of Exeter, Exeter, EX4 4QE, UK), AC(Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21210, USA), AD(Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA) |
| Journal: | The Planetary Science Journal, Volume 6, Issue 3, id.63, 17 pp. |
| Publication Date: | Mar 2025 |
| Origin: | American Astronomical Society |
| Keywords: | Polar jets, Atmospheric dynamics, Atmospheric variability, Mars, Titan, Atmospheric circulation, 1274, 2300, 2119, 1007, 2186, 112 |
| Abstract Copyright: | © 2025. The Author(s). Published by the American Astronomical Society. |
| DOI: | https://doi.org/10.3847/PSJ/adba4b |
| Bibliographic Code: | 2025PSJ.....6...63S |
| Abstract: | Polar vortices are a common feature in the solar system, but their structure varies between planets. Although polar vortices are characterized by a coherent region of high potential vorticity (PV) in the polar regions, the meridional variation of PV ranges from strong monopolar to annular distributions. The reduced stability of an annular vortex compared to a monopolar vortex may lead to increased horizontal transport between the midlatitudes and the poles, but this has yet to be thoroughly investigated. Here we perform such an investigation by quantifying the horizontal mixing in polar vortices of varying PV structure, for both a two-dimensional shallow-water model and a three-dimensional general circulation model (GCM). Good agreement is found between the models, with both models indicating that both vortices maintain a horizontal mixing barrier that isolates the polar regions from the extratropics. The primary difference between the two vortex structures is on the interior of the vortex edge, where there is increased mixing inside the annular vortex but a clear reduction of mixing inside the monopolar vortex. In the three-dimensional GCM, a "subvortex" region is identified below the annular polar vortex that allows for more transport of material into the polar regions than the subvortex of the monopolar vortex. This suggests a potential pathway for transport into annular vortices that does not occur for monopolar vortices. Although we start from a Mars-like atmosphere for simplicity and flexibility, our results should describe other terrestrial planets/moons with broad polar vortices with coherent regions of high PV. |
| Title: | In situ, Surface-deployed Distributed Instruments for Planetary Science: Scientific Opportunities and Technology Feasibility |
|---|---|
| Authors: | Rossi, Federico; Anderson, Robert C.; Bandyopadhyay, Saptarshi; Brandon, Erik; Goel, Ashish; Vander Hook, Joshua; Mischna, Michael; Villarreal, Michaela; Wronkiewicz, Mark |
| Affiliation: | AA(Jet Propulsion Laboratory—California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA), AB(Jet Propulsion Laboratory—California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA), AC(Jet Propulsion Laboratory—California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA), AD(Jet Propulsion Laboratory—California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA), AE(Jet Propulsion Laboratory—California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA), AF(Jet Propulsion Laboratory—California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA), AG(Jet Propulsion Laboratory—California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA), AH(Jet Propulsion Laboratory—California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA), AI(Jet Propulsion Laboratory—California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA) |
| Journal: | The Planetary Science Journal, Volume 6, Issue 3, id.66, 38 pp. |
| Publication Date: | Mar 2025 |
| Origin: | American Astronomical Society |
| Keywords: | Planetary science, Planetary atmospheres, Planetary dynamics, Planetary magnetospheres, Landers, Planetary probes, Lunar probes, Lunar seismology, Planetary interior, 1255, 1244, 2173, 997, 901, 1252, 969, 973, 1248, Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Computer Science - Multiagent Systems, Physics - Atmospheric and Oceanic Physics, Physics - Geophysics |
| Abstract Copyright: | © 2025. The Author(s). Published by the American Astronomical Society. |
| DOI: | https://doi.org/10.3847/PSJ/ada9ec |
| Bibliographic Code: | 2025PSJ.....6...66R |
| Abstract: | In this paper, we assess the scientific promise and technology feasibility of in situ distributed instruments for planetary surface and atmospheric science. A distributed instrument is an instrument designed to collect spatially and temporally correlated data from multiple networked, geographically distributed point sensors. Distributed instruments are ubiquitous in Earth science, where they are routinely employed for weather and climate science, seismic studies and resource prospecting, and detection of industrial emissions. However, to date, their adoption in planetary science has been minimal. It is natural to ask whether this lack of adoption is driven by low potential to address high-priority questions in planetary science, immature technology, or both. To address this question, we survey high-priority planetary science questions that are uniquely well suited to distributed, surface-deployed, in situ instruments. We identify four areas of research where such distributed instruments hold promise to unlock answers that are largely inaccessible to monolithic sensors or remote sensing approaches, or can complement existing approaches, namely, in weather and climate studies; localization of seismic events on rocky and icy bodies; localization of trace gas emissions; and magnetometry studies of internal planetary composition. Next, we survey enabling technologies for distributed sensors and assess their maturity. We identify sensor placement (including descent and landing on planetary surfaces), power, and instrument autonomy as three key areas requiring further investment to enable future distributed instruments. Overall, this work shows that distributed instruments hold great promise for planetary science, and paves the way for follow-up studies of future distributed instruments for solar system science. |
| Title: | Martian Atmospheric Disturbances From Orbital Images and Surface Pressure at Jezero Crater, Mars, During Martian Year 36 |
|---|---|
| Authors: | Sánchez-Lavega, A.; Larsen, E.; del Rio-Gaztelurrrutia, T.; Hernández-Bernal, J.; Ordóñez-Etxebarría, I.; Hueso, R.; Tanguy, B.; Lemmon, M.; Juarez, M. de la Torre; Martínez, G. M.; Munguira, A.; Rodríguez-Manfredi, J. A.; Harri, A.-M.; Pla-García, J.; Toledo, D.; Newman, C. |
| Affiliation: | AA(Escuela de Ingeniería de Bilbao, Universidad País Vasco, UPV/EHU, Bilbao, Spain;), AB(Escuela de Ingeniería de Bilbao, Universidad País Vasco, UPV/EHU, Bilbao, Spain;), AC(Escuela de Ingeniería de Bilbao, Universidad País Vasco, UPV/EHU, Bilbao, Spain;), AD(Laboratoire de Méteorologie Dynamique, Sorbonne Université, Paris, France;), AE(Planetario de Pamplona, Pamplona, Spain), AF(Escuela de Ingeniería de Bilbao, Universidad País Vasco, UPV/EHU, Bilbao, Spain;), AG(LESIA, Observatoire de Paris, Meudon, France), AH(Space Science Institute, College Station, TX, USA;), AI(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA;), AJ(Lunar and Planetary Institute, Houston, TX, USA; Centro de Astrobiología (INTA-CSIC), Madrid, Spain;), AK(Escuela de Ingeniería de Bilbao, Universidad País Vasco, UPV/EHU, Bilbao, Spain;), AL(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AM(Finnish Meteorological Institute, Helsinki, Finland;), AN(Centro de Astrobiología (INTA-CSIC), Madrid, Spain;), AO(Instituto Nacional de Técnica Aeroespacial, INTA, Madrid, Spain;), AP(Aeolis Research, Chandler, AZ, USA;) |
| Journal: | Journal of Geophysical Research: Planets, Volume 130, Issue 1, page 2024JE008565, 26 pp. |
| Publication Date: | Jan 2025 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | planet, mars, atmosphere, dynamics, tides, cyclones, Astrophysics - Earth and Planetary Astrophysics |
| Abstract Copyright: | © 2025 The Author(s). |
| DOI: | https://doi.org/10.1029/2024JE008565 |
| Bibliographic Code: | 2025JGRE..13008565S |
| Abstract: | We present a study of atmospheric disturbances at Jezero Crater, Mars, using ground-based measurements of surface pressure by the Perseverance rover in combination with orbital images from the Mars Express and Mars Reconnaissance Orbiter missions. The study starts at L<SUB>s</SUB> ∼ 13.3° in MY36 (6 March 2021) and extends up to L<SUB>s</SUB> ∼ 30.3° in MY37 (28 February 2023). We focus on the characterization of the major atmospheric phenomena at synoptic and planetary-scales. These are the thermal tides (measured up to the sixth component), long-period pressure oscillations (periods >1 sol), the Aphelion Cloud Belt, and the occasional development of regional dust storms over Jezero. We present the seasonal evolution of the amplitudes and phases of the thermal tides and their relation with the atmospheric dust content (optical depth). Three regional dust storms and one polar storm extending over Jezero produced an increase in the diurnal and semidiurnal amplitudes but resulted in inverse responses in their phases. We show that the primary regular wave activity is due to baroclinic disturbances with periods of 2─4 sols and amplitudes ∼ 1─15 Pa increasing with dust content, in good agreement with theoretical predictions by model calculations. The spacecraft images show a number of arc-shaped, spiral and irregular cyclonic vortices, traced by dust and clouds at the edge of the North Polar Cap, that could be behind some of the pressure oscillations measured at Jezero. |
| Title: | Profiling Near-surface Winds on Mars Using Attitude Data from Mars 2020 Ingenuity |
|---|---|
| Authors: | Jackson, Brian; Fenton, Lori; Brown, Travis; Munguira, Asier; Martinez, German; Newman, Claire; Viúdez-Moreiras, Daniel; Golombek, Matthew; Lorenz, Ralph; Paton, Mark D.; Conway, Dylan |
| Affiliation: | AA(Department of Physics, Boise State University, 1910 University Drive, Boise, ID 83725-1570, USA; Carl Sagan Center, SETI Institute, Mountain View, CA, USA), AB(Carl Sagan Center, SETI Institute, Mountain View, CA, USA), AC(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA), AD(Universidad del País Vasco UPV/EHU, Bilbao, Spain), AE(Lunar and Planetary Institute, 3600 Bay Area Boulevard, Office 2029, Houston, TX 77058, USA; Centro de Astrobiologia (CAB, CSIC-INTA) and National Institute for Aerospace Technology (INTA), Madrid, Spain), AF(Aeolis Research, Tucson, AZ, USA), AG(Centro de Astrobiologia (CAB, CSIC-INTA) and National Institute for Aerospace Technology (INTA), Madrid, Spain), AH(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA), AI(Johns Hopkins Applied Physics Laboratory, 1100 Johns Hopkins Road, Laurel, MD, USA), AJ(Finnish Meteorological Institute, PO Box 503, FIN-00101 Helsinki, Finland), AK(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA) |
| Journal: | The Planetary Science Journal, Volume 6, Issue 1, id.21, 20 pp. |
| Publication Date: | Jan 2025 |
| Origin: | American Astronomical Society |
| Keywords: | Planetary atmospheres, Mars, 1244, 1007, Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics |
| Abstract Copyright: | © 2025. The Author(s). Published by the American Astronomical Society. |
| DOI: | https://doi.org/10.3847/PSJ/ad8b41 |
| Bibliographic Code: | 2025PSJ.....6...21J |
| Abstract: | We used attitude data from the Mars Ingenuity helicopter with a simple steady-state model to estimate wind speeds and directions at altitudes between 3 and 24 m, the first time winds at such altitudes have been probed on Mars. We compared our estimates to wind data from the meteorology package MEDA on board the Mars 2020 Perseverance rover and to predictions from meteorological models. Wind directions inferred from Ingenuity data agreed with the directions measured by MEDA, when the latter were available, but deviated from model-predicted directions by as much as 180° in some cases. The inferred wind speeds are often much higher than expected. For example, meteorological predictions suggest that Ingenuity should not have seen wind speeds above about 15 m s<SUP>−1</SUP> during its 59th flight, but we inferred speeds reaching nearly 25 m s<SUP>−1</SUP>. For flights during which we have MEDA data to compare to, inferred wind speeds imply friction velocities >1 m s<SUP>−1</SUP> and roughness lengths >10 cm, which seem implausibly large. These results suggest that Ingenuity was probing winds sensitive to aerodynamic conditions hundreds of meters upwind instead of the conditions very near Mars 2020, but they may also reflect a need for updated boundary layer wind models. An improved model for Ingenuity's aerodynamic response that includes the effects of transient winds may also modify our results. In any case, the work here provides a foundation for exploration of planetary boundary layers using drones and suggests important future avenues for research and development. |
| Title: | Inferred wind speed and direction during the descent and landing of Perseverance on Mars |
|---|---|
| Authors: | Paton, M. D.; Savijärvi, H.; Harri, A.-M.; Leino, J.; Bertrand, T.; Viúdez-Moreiras, D.; Lorenz, R. D.; Newman, C. |
| Affiliation: | AA(Finnish Meteorological Institute, PO Box 503, FIN-00101 Helsinki, Finland), AB(Finnish Meteorological Institute, PO Box 503, FIN-00101 Helsinki, Finland), AC(Finnish Meteorological Institute, PO Box 503, FIN-00101 Helsinki, Finland), AD(Finnish Meteorological Institute, PO Box 503, FIN-00101 Helsinki, Finland), AE(LESIA, Observatoire de Paris, 92195 Meudon, France), AF(Centro de Astrobiologia (CAB, CSIC-INTA) and National Institute for Aerospace Technology (INTA), Madrid, Spain), AG(Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA), AH(Aeolis Research, Chandler, AZ, USA) |
| Journal: | Icarus, Volume 415, id.116045. |
| Publication Date: | Jun 2024 |
| Origin: | Elsevier BV |
| Keywords: | Mars, Wind, Atmosphere, Perseverance, Heat shield |
| Abstract Copyright: | © 2024 Elsevier Inc. All rights reserved. |
| DOI: | https://doi.org/10.1016/j.icarus.2024.116045 |
| Bibliographic Code: | 2024Icar..41516045P |
| Abstract: | Perseverance successfully parachuted into Jezero crater close to its western rim on a Martian spring afternoon. In situ observations of the wind conditions during the parachute and powered descent are unavailable. These observations are important for characterising the Planetary Boundary Layer (PBL) and to better constrain atmospheric conditions in Jezero crater. We infer the winds during Perseverance's parachute descent from an altitude of 12 km down to 2 km by fitting a trajectory model to the reconstructed trajectory data published by the M2020 Entry, Descent and Landing team. Below 2 km altitude we infer the winds by analysing a High Resolution Imaging Science Experiment (HiRISE) image of the landing site that was obtained about one sol after the landing. Our inferred wind speed and direction profile indicate high speed winds at an altitude of 7 km blowing from the east and at 3 km blowing from the southwest. Below an altitude of 2 km, the winds are inferred to be easterlies. The heat shield impact on the surface was observed by Perseverance's Lander Vision System Camera (LCAM). Afterwards, ejecta clouds were observed moving towards the north of the impact site. These observations, together with the orientation of the parachute canopy on the surface, suggest near-surface winds at the time were southerlies. We have inferred the wind speed and direction during Perseverance's descent that are consistent with its horizontal motion as revealed by trajectory data and HiRISE image. Comparisons with atmospheric models suggest the high speed winds could be related to topographic forcing. This study provides constraints for atmospheric modelling and advances the characterisation of winds in Jezero crater, focusing on the vertical structure of the complex wind field present in the crater. |
| Title: | Perseverance MEDA Atmospheric Pressure Observations—Initial Results |
|---|---|
| Authors: | Harri, Ari-Matti; Paton, Mark; Hieta, Maria; Polkko, Jouni; Newman, Claire; Pla-Garcia, Jorge; Leino, Joonas; Mäkinen, Terhi; Kauhanen, Janne; Jaakonaho, Iina; Sánchez-Lavega, Agustin; Hueso, Ricardo; Genzer, Maria; Lorenz, Ralph; Lemmon, Mark; Vicente-Retortillo, Alvaro; Tamppari, Leslie K.; Viudez-Moreiras, Daniel; Torre-Juarez, Manuel de la; Savijärvi, Hannu; Rodríguez-Manfredi, Javier A.; Martinez, German |
| Affiliation: | AA(Finnish Meteorological Institute, Helsinki, Finland), AB(Finnish Meteorological Institute, Helsinki, Finland), AC(Finnish Meteorological Institute, Helsinki, Finland), AD(Finnish Meteorological Institute, Helsinki, Finland), AE(Aeolis Research, Chandler, AZ USA), AF(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AG(Finnish Meteorological Institute, Helsinki, Finland), AH(Finnish Meteorological Institute, Helsinki, Finland), AI(Finnish Meteorological Institute, Helsinki, Finland), AJ(Finnish Meteorological Institute, Helsinki, Finland), AK(UPV/EHU, Bilbao, Spain), AL(UPV/EHU, Bilbao, Spain), AM(Finnish Meteorological Institute, Helsinki, Finland), AN(Johns Hopkins Applied Physics Laboratory, Laurel, MD USA), AO(Space Science Institute, College Station, TX USA), AP(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AQ(Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA USA), AR(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AS(Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA USA), AT(Finnish Meteorological Institute, Helsinki, Finland), AU(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AV(Lunar and Planetary Institute, Houston, TX USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 129, Issue 3, article id. e2023JE007880. |
| Publication Date: | Mar 2024 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Martian atmosphere, atmospheric pressure cycle, atmospheric tidal components, pressure measurement, baroclinic and barotropic wave forms, dust devil |
| Abstract Copyright: | 2024. The Authors. |
| DOI: | https://doi.org/10.1029/2023JE007880 |
| Bibliographic Code: | 2024JGRE..12907880H |
| Abstract: | The Mars2020 Perseverance Rover landed successfully on the Martian surface on the Jezero Crater floor (18.44°N, 77.45°E) at Martian solar longitude, L<SUB>s</SUB>, ∼5° in February 2021. Since then, it has produced highly valuable environmental measurements with a versatile scientific payload including the MEDA (Mars Environmental Dynamics Analyzer) suite of environmental sensors. One of the MEDA systems is the PS pressure sensor system, which weighs 40 g and has an estimated absolute accuracy of better than 3.5 Pa and a resolution of 0.13 Pa. We present initial results from the first 414 sols of Martian atmospheric surface pressure observations by the PS, whose performance was found to meet its specifications. Observed sol-averaged atmospheric pressures follow an anticipated pattern of pressure variation in the course of the advancing season and are consistent with data from other landing missions. The observed daily pressure amplitude varies by ∼2%-5 % of the sol-averaged pressure, with absolute amplitude 10-35 Pa in an approximately direct relationship with airborne dust. During a regional dust storm, which began at L<SUB>s</SUB> ∼ 135°, the daily pressure amplitude roughly doubled. The daily pressure variations were found to be remarkably sensitive to the seasonal evolution of the atmosphere. In particular, analysis of the daily pressure signature revealed diagnostic information likely related to the regional scale structure of the atmosphere. Comparison of Perseverance pressure observations with data from other landers reveals the global scale seasonal behavior of Mars' atmosphere. |
| Title: | Why Are Mountaintops Cold? The Transition of Surface Lapse Rate on Dry Planets |
|---|---|
| Authors: | Fan, Bowen; Jansen, Malte F.; Mischna, Michael A.; Kite, Edwin S. |
| Affiliation: | AA(Department of the Geophysical Sciences, University of Chicago, Chicago, IL USA), AB(Department of the Geophysical Sciences, University of Chicago, Chicago, IL USA), AC(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AD(Department of the Geophysical Sciences, University of Chicago, Chicago, IL USA) |
| Journal: | Geophysical Research Letters, Volume 50, Issue 23, article id. e2023GL106683. |
| Publication Date: | Dec 2023 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | terrestrial planets, atmospheres, astrobiology, Astrophysics - Earth and Planetary Astrophysics, Physics - Atmospheric and Oceanic Physics, Physics - Geophysics |
| Abstract Copyright: | 2023 The Authors. |
| DOI: | https://doi.org/10.1029/2023GL106683 |
| Bibliographic Code: | 2023GeoRL..5006683F |
| Abstract: | Understanding surface temperature is important for habitability. Recent work on Mars has found that the dependence of surface temperature on elevation (surface lapse rate) converges to zero in the limit of a thin CO<SUB>2</SUB> atmosphere. However, the mechanisms that control the surface lapse rate are still not fully understood. It remains unclear how the surface lapse rate depends on both greenhouse effect and surface pressure. Here, we use climate models to study when and why "mountaintops are cold." We find the tropical surface lapse rate increases with the greenhouse effect and with surface pressure. The greenhouse effect dominates the surface lapse rate transition and is robust across latitudes. The pressure effect is important at low latitudes in moderately opaque (τ ∼ 0.1) atmospheres. A simple model provides insights into the mechanisms of the transition. Our results suggest that topographic cold-trapping may be important for the climate of arid planets. |
| Title: | Simulated Atmospheric Response to Large-Scale Dust Forcing and Implications for Martian Dust Storm Growth |
|---|---|
| Authors: | Wang, Huiqun; Toigo, Anthony D.; Richardson, Mark I. |
| Affiliation: | AA(Center for Astrophysics|Harvard-Smithsonian, Cambridge, MA USA), AB(John Hopkins University Applied Physics Laboratory, Laurel, MD USA), AC(Aeolis Research, Chandler, AZ USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 128, Issue 10, article id. e2023JE007956. |
| Publication Date: | Oct 2023 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, atmosphere, dust storm, model, circulation |
| Abstract Copyright: | 2023. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2023JE007956 |
| Bibliographic Code: | 2023JGRE..12807956W |
| Abstract: | The response of tidal, "weather," and intra-seasonal transient eddies in a global numerical model to dust imposed in different latitudinal bands and seasons has been examined in order to investigate the impact of regional scale dust storm episodes on large-scale circulation and hence on further dust storm development. The eddy kinetic energy and surface friction speed for each eddy group were derived using wavelet analysis from multi-year simulations and statistical comparisons were made among the experiments. Results show that different eddy categories respond differently to dust storm forcing, and that the responses are dependent upon both modeled storm location and season. These responses can be cast in terms of potential positive and negative feedbacks on large-scale dust storm development and have implications for the cascade of dust storms through different scales and circulation components. The model results suggest positive feedback between northern high latitude dust forcing and weather transients in the same latitudes in Quartober (L<SUB>s</SUB> = 185°-245°), which weakens or disappears in Sixtober (L<SUB>s</SUB> = 295°-360°). The results also suggest positive feedback between dust heating in the tropics/subtropics and tidal eddies, which may enhance the southward transport of "flushing" storms. However, southern high latitude dust forcing suppresses northern weather transients in both pseudo-season sextons, suggesting negative feedback which may terminate northern frontal/flushing dust storm sequences and hence weaken further development of a dust storm episode through this mechanism. |
| Title: | Dust Lifting Observations With the Mars Science Laboratory Navigation Cameras |
|---|---|
| Authors: | Guzewich, Scott D.; Mason, Emily L.; Lemmon, Mark T.; Newman, Claire E.; Lewis, Kevin W. |
| Affiliation: | AA(NASA Goddard Space Flight Center, Greenbelt, MD USA), AB(NASA Goddard Space Flight Center, Greenbelt, MD USA; University of Maryland Baltimore County, Catonsville, MD USA; Center for Research and Exploration in Space Science and Technology II, NASA, GSFC, Greenbelt, MD USA), AC(Space Science Institute, Boulder, CO USA), AD(Aeolis Research, Pasadena, CA USA), AE(Johns Hopkins University, Baltimore, MD USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 128, Issue 10, article id. e2023JE007959. |
| Publication Date: | Oct 2023 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, dust, Mars Science Laboratory, dust devil, aeolian |
| Abstract Copyright: | 2023. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2023JE007959 |
| Bibliographic Code: | 2023JGRE..12807959G |
| Abstract: | Martian dust lifting is believed to occur through two primary mechanisms: dust devils and wind stress forced dust lifting. Gale Crater's varied terrain and meteorology provide a unique in situ perspective on Martian dust lifting, with the Mars Science Laboratory Curiosity rover passing through both conditions and locations detrimental to dust lifting (e.g., the crater floor) and those with active sand motion and frequent dust lifting (e.g., the Bagnold Dunes). Between L<SUB>s</SUB> = 248° in Mars Year 33 and L<SUB>s</SUB> = 51° in Mars Year 37, over ∼3.5 Mars years and 2,300 sols, the rover's Navigation Cameras took 1,260 dedicated image sequences to search for dust lifting. Approximately 42.7% of all sequences, and 9.5% of the total images have shown active dust lifting, both dust devils and linear/straight-line wind stress dust lifting. 79% of dust lifting events are classified as dust devils, while ∼16% are linear wind stress dust lifting and the remainder are of an indeterminate type. We analyze this large catalog of dust lifting events to provide ground truth on theoretical and model expectations of dust lifting and show that dust lifting in Gale Crater occurs throughout the Martian year, is strongly peaked in frequency near solar noon (even after accounting for observational biases), and that dust lifting shows an affinity for sand-covered surfaces which highlights the importance of saltating sand grains for Martian dust lifting in both dust devils and wind stress forced lifting. |
| Title: | Atmospheric CO<SUB>2</SUB> Depletion Near the Surface in the Martian Polar Regions |
|---|---|
| Authors: | Piqueux, Sylvain; Hayne, Paul O.; Kleinböhl, Armin; Kass, David M.; Schreier, Mathias; McCleese, Daniel J.; Richardson, Mark I.; Schofield, John T.; Heavens, Nicholas; Shirley, James H. |
| Affiliation: | AA(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AB(Department of Astrophysical and Planetary Sciences, Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, Boulder, CO USA), AC(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AD(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AE(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AF(Synoptic Sciences, Pasadena, CA USA), AG(Aeolis Research, Chandler, AZ USA), AH(Synoptic Sciences, Pasadena, CA USA), AI(Space Science Institute, Boulder, CO USA), AJ(TorqueFX, Simi Valley, CA USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 128, Issue 6, article id. e2022JE007332. |
| Publication Date: | Jun 2023 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, ice, depletion, temperature, CO<SUB>2</SUB> |
| Abstract Copyright: | 2023 American Geophysical Union. All Rights Reserved. California Institute of Technology. Government sponsorship acknowledged. |
| DOI: | https://doi.org/10.1029/2022JE007332 |
| Bibliographic Code: | 2023JGRE..12807332P |
| Abstract: | The kinetic temperature of the Martian seasonal caps is controlled by the partial pressure of atmospheric CO<SUB>2</SUB> at the surface. When carbon dioxide condenses, typically near the poles, light non-condensable species (Ar, N<SUB>2</SUB>, CO, etc.) accumulate in the atmosphere, resulting in a decrease of the CO<SUB>2</SUB> partial pressure and depressing the local frost point temperature. The buoyant air should mix laterally and vertically within the polar vortices. Observations show that the Martian seasonal caps' kinetic temperatures are ∼0-4 K below the expected CO<SUB>2</SUB> frost point, depending on latitude and season, indicating atmospheric CO<SUB>2</SUB> gas depletion at the surface/atmosphere interface. In the North and South, we find relatively similar non-condensable peak enhancement factors (e.g., EF<SUB>NC</SUB> ∼ 6-8, up to ∼8.7 in the North) at most latitudes, confirming the efficient meridional mixing within the polar vortices, despite steep surface condensation gradients. In the South, this surface enhancement is similar to column-integrated values derived from Gamma Ray Spectrometer data, indicating efficient vertical mixing. But in the North, the surface depletion is much larger than in the entire column, suggesting poor vertical mixing. Reduced infrared emission of the seasonal caps stemming from CO<SUB>2</SUB> depletion is not a major energy balance factor. This work illustrates how the atmosphere's composition at the surface can be significantly different from column-integrated values. |
| Title: | Unstructured grid dynamical modeling of planetary atmospheres using planetMPAS: The influence of the rigid lid, computational efficiency, and examples of Martian and Jovian application |
|---|---|
| Authors: | Lian, Yuan; Richardson, Mark I. |
| Affiliation: | AA(Aeolis Research, Chandler, AZ, 85224, USA), AB(Aeolis Research, Chandler, AZ, 85224, USA) |
| Journal: | Planetary and Space Science, Volume 229, article id. 105663. |
| Publication Date: | May 2023 |
| Origin: | Elsevier BV |
| Keywords: | Astrophysics - Earth and Planetary Astrophysics |
| Abstract Copyright: | (c) 2023 The Authors |
| DOI: | https://doi.org/10.1016/j.pss.2023.105663 |
| Bibliographic Code: | 2023P&SS..22905663L |
| Abstract: | We present a new planetary global circulation model, planetMPAS, based on the state-of-the-art NCAR MPAS (Model for Prediction Across Scales) General Circulation Model. Taking advantage of the cross compatibility between WRF (Weather Research and Forecasting Model) and MPAS, planetMPAS includes most of the planetWRF physics parameterization schemes for terrestrial planets such as Mars and Titan. PlanetMPAS also includes a set of physics that represents radiative transfer, dry convection, moist convection and its associated microphysics for the Jovian atmosphere. We demonstrate that, despite the rigid-lid approximation, planetMPAS is suitable to simulate the climate systems in the Martian and Jovian atmospheres. Simulations using planetMPAS show that the new model can reproduce many aspects of the observed features on Mars and Jupiter, such as the seasonal CO2 cycle, polar argon enrichment, zonal mean temperature, and qualitative dust opacity on Mars, as well as the equatorial superrotation and banded zonal wind patterns on Jupiter. |
| Title: | Sediment-moving winds and abrasion on Titan: Implications for yardangs |
|---|---|
| Authors: | MacKenzie, Shannon M.; Runyon, Kirby D.; Yu, Xinting; Kok, Jasper F.; Newman, Claire; Lorenz, Ralph D.; Comola, Francesco |
| Affiliation: | AA(Johns Hopkins University Applied Physics Laboratory, 1001 Johns Hopkins Road, Laurel, 20723, MD, USA), AB(Johns Hopkins University Applied Physics Laboratory, 1001 Johns Hopkins Road, Laurel, 20723, MD, USA; Planetary Sciences Institute, Tuscon, 85719-2395, AZ, USA), AC(Department of Earth and Planetary Sciences, University of California Santa Cruz, 1156 High Street, Santa Cruz, 95064, CA, USA), AD(Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA, USA), AE(Aeolis Research, Pasadena, 91107, CA, USA), AF(Johns Hopkins University Applied Physics Laboratory, 1001 Johns Hopkins Road, Laurel, 20723, MD, USA), AG(Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA, USA) |
| Journal: | Icarus, Volume 394, article id. 115433. |
| Publication Date: | Apr 2023 |
| Origin: | Elsevier BV |
| Keywords: | Titan, Abrasion, Yardangs |
| Abstract Copyright: | (c) 2023 Elsevier Inc. |
| DOI: | https://doi.org/10.1016/j.icarus.2023.115433 |
| Bibliographic Code: | 2023Icar..39415433M |
| Abstract: | Titan's surface is expected to have a wide variety of sediments available due to both to aeolian and fluvial processes and to the organics that fall out of the atmosphere. As the vast dune fields that almost encircle Titan's equator indicate, Titan's near surface winds are sufficient to saltate particles. It is perhaps unsurprising then that putative yardangs - extended linear features carved by wind-mobilized sediment - have been found with Cassini RADAR data. However, few such candidates have been identified and are only found in the midlatitudes, a terrain whose geological characteristics (e.g. provenance, grain size distribution, composition) are still generally unknown. Therefore, to provide new insight into the possibility of yardang formation on Titan, we investigate the erodibility of Titan-relevant materials under plausible mid-latitude conditions. We found the most favorable conditions for abrasion in our study are created by small (≈ 100 μm diameter) particles with weak cohesion and weak (water-ice) targets; particle density is not a controlling factor. |
| Title: | Near Surface Atmospheric Temperatures at Jezero From Mars 2020 MEDA Measurements |
|---|---|
| Authors: | Munguira, A.; Hueso, R.; Sánchez-Lavega, A.; de la Torre-Juarez, M.; Martínez, G. M.; Newman, C. E.; Sebastian, E.; Lepinette, A.; Vicente-Retortillo, A.; Chide, B.; Lemmon, M. T.; Bertrand, T.; Lorenz, R. D.; Banfield, D.; Gómez-Elvira, J.; Martín-Soler, J.; Navarro, S.; Pla-García, J.; Rodríguez-Manfredi, J. A.; Romeral, J.; Smith, M. D.; Torres, J. |
| Affiliation: | AA(Física Aplicada, Escuela de Ingeniería de Bilbao, Universidad del País Vasco UPV/EHU, Bilbao, Spain), AB(Física Aplicada, Escuela de Ingeniería de Bilbao, Universidad del País Vasco UPV/EHU, Bilbao, Spain), AC(Física Aplicada, Escuela de Ingeniería de Bilbao, Universidad del País Vasco UPV/EHU, Bilbao, Spain), AD(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AE(Lunar and Planetary Institute, Houston, TX USA), AF(Aeolis Research, Chandler, AZ USA), AG(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AH(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AI(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AJ(Los Alamos National Laboratory, Los Alamos, NM USA), AK(Space Science Institute, College Station, TX USA), AL(LESIA, Observatoire de Paris, Meudon, France), AM(Johns Hopkins Applied Physics Laboratory, Laurel, MD USA), AN(Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY USA), AO(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AP(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AQ(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AR(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AS(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AT(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AU(NASA Goddard Space Flight Center, Greenbelt, MD USA), AV(Centro de Astrobiología (INTA-CSIC), Madrid, Spain) |
| Journal: | Journal of Geophysical Research: Planets, Volume 128, Issue 3, article id. e2022JE007559. |
| Publication Date: | Mar 2023 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, meteorology, planetary boundary layer, atmospheric temperatures, Mars 2020—Perseverance, MEDA |
| Abstract Copyright: | 2023. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2022JE007559 |
| Bibliographic Code: | 2023JGRE..12807559M |
| Abstract: | The Mars Environmental Dynamics Analyzer instrument on Mars 2020 has five Atmospheric Temperature Sensors at two altitudes (0.84 and 1.45 m) plus a Thermal InfraRed Sensor that measures temperatures on the surface and at ∼40 m. We analyze the measurements from these sensors to describe the evolution of temperatures in Jezero up to mission sol 400 (solar longitude L<SUB>S</SUB> = 13°-203°). The diurnal thermal cycle is characterized by a daytime convective period and a nocturnal stable atmosphere with a variable thermal inversion. We find a linear relationship between the daytime temperature fluctuations and the vertical thermal gradient with temperature fluctuations that peak at noon with typical values of 2.5 K at 1.45 m. In the late afternoon (∼17:00 Local True Solar Time), the atmosphere becomes vertically isothermal with vanishing fluctuations. We observe very small seasonal changes in air temperatures during the period analyzed. This is related to small changes in solar irradiation and dust opacity. However, we find significant changes in surface temperatures that are related to the variety of thermal inertias of the terrains explored along the traverse of Perseverance. These changes strongly influence the vertical thermal gradient, breaking the nighttime thermal inversion over terrains of high thermal inertia. We explore possible detections of atmospheric tides on near-surface temperatures and we examine variations in temperatures over timescales of a few sols that could be indicative of atmospheric waves affecting near-surface temperatures. We also discuss temperatures during a regional dust storm at L<SUB>S</SUB> = 153°-156° that simultaneously warmed the near surface atmosphere while cooling the surface. |
| Title: | Comparison of Ventifact Orientations and Recent Wind Direction Indicators on the Floor of Jezero Crater, Mars |
|---|---|
| Authors: | Herkenhoff, K. E.; Sullivan, R. J.; Newman, C. E.; Paar, G.; Baker, M.; Viúdez-Moreiras, D.; Ashley, J. W.; Bechtold, A.; Nuñez, J. I. |
| Affiliation: | AA(U.S. Geological Survey Astrogeology Science Center, Flagstaff, AZ USA), AB(Cornell University, Ithaca, NY USA), AC(Aeolis Research, Chandler, AZ USA), AD(Joanneum Research, Graz, Austria), AE(Smithsonian National Air and Space Museum, Washington, DC USA), AF(Centro de Astrobiologia, Madrid, Spain), AG(NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AH(University of Vienna, Vienna, Austria), AI(Applied Physics Laboratory, Johns Hopkins University, Laurel, MD USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 128, Issue 3, article id. e2022JE007599. |
| Publication Date: | Mar 2023 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, ventifacts, climate, wind, Jezero, Perseverance |
| Abstract Copyright: | 2023 Jet Propulsion Laboratory, California Institute of Technology and The Authors. Government sponsorship acknowledged. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA. |
| DOI: | https://doi.org/10.1029/2022JE007599 |
| Bibliographic Code: | 2023JGRE..12807599H |
| Abstract: | Wind-abraded rocks and aeolian bedforms have been observed at the Mars 2020 Perseverance landing site, providing evidence for recent and older wind directions. This study reports orientations of aeolian features measured in Perseverance images to infer formative wind directions. It compares these measurements with orbital observations, climate model predictions, and wind data acquired by the Mars Environmental Dynamics Analyzer. Three-dimensional orientations of flute textures on rocks, regolith wind tails extending from behind obstacles, and other aeolian features were measured using Digital Terrain Models derived from Mastcam-Z and navigation camera (Navcam) stereo images. Orientations of rock flutes measured in images acquired through Sol (Martian day) 400 yielded a mean azimuth of 94° ± 7° (wind from the west). However, similar measurements of regolith wind tails indicate that recent sand-driving winds have been blowing from the east-southeast, nearly the opposite direction (mean azimuth = 285° ± 15°). Atmospheric modeling generally predicts net annual sand transport from the east-southeast at present, consistent with Perseverance regolith wind tail and orbital observations. The orientation of ventifact flutes thus suggests that they were formed under a different climate regime. Differences in orientations of recent and paleo-wind indicators have been noted at other Mars landing sites and may result from major orbital/axial changes that can cause significant changes in atmospheric circulation. Orientation differences between modern and older wind direction indicators at Jezero are useful clues to the climate history of the region. |
| Title: | Dynamical Core Damping of Thermal Tides in the Martian Atmosphere |
|---|---|
| Authors: | Lian, Yuan; Richardson, Mark I.; Newman, Claire E.; Lee, Chris; Toigo, Anthony; Guzewich, Scott; Yelle, Roger V. |
| Affiliation: | AA(Aeolis Research, Chandler, Arizona), AB(Aeolis Research, Chandler, Arizona), AC(Aeolis Research, Chandler, Arizona), AD(Aeolis Research, Chandler, Arizona; University of Toronto, Toronto, Ontario, Canada; University of Toronto, Toronto, Ontario, Canada), AE(The Johns Hopkins University, Baltimore, Maryland), AF(Goddard Space Flight Center, Greenbelt, Maryland), AG(The University of Arizona, Tucson, Arizona) |
| Journal: | Journal of the Atmospheric Sciences, Volume 80, Issue 2, p.535-547. |
| Publication Date: | Feb 2023 |
| Origin: | American Meteorological Society |
| Abstract Copyright: | 2023: American Meteorological Society |
| DOI: | https://doi.org/10.1175/JAS-D-22-0026.1 |
| Bibliographic Code: | 2023JAtS...80..535L |
| Abstract: | Atmospheric oscillations with daily periodicity are observed in in situ near-surface pressure, temperature, and winds observations and also in remotely sensed temperature and pressure observations of the Martian atmosphere. Such oscillations are interpreted as thermal tides driven by the diurnal cycle of solar radiation and occur at various frequencies, with the most prominent being the diurnal, semidiurnal, terdiurnal, and quadiurnal tides. Mars global circulation models reproduce these tides with varying levels of success. Until recently, both the MarsWRF and newly developed MarsMPAS models were able to produce realistic diurnal and semidiurnal tide amplitudes but predicted higher-order mode amplitudes that were significantly weaker than observed. We use linear wave analysis to show that the divergence damping applied within both MarsWRF and MarsMPAS is responsible for suppressing the amplitude of thermal tides with frequency greater than 2 per sol, despite being designed to suppress only acoustic wave modes. Decreasing the strength of the divergence damping in MarsWRF and MarsMPAS allows for excellent prediction of the higher-order tidal modes. This finding demonstrates that care must be taken when applying numerical dampers and filters that may eliminate some desired dynamical features in planetary atmospheres. |
| Title: | Convective Vortices and Dust Devils Detected and Characterized by Mars 2020 |
|---|---|
| Authors: | Hueso, R.; Newman, C. E.; del Río-Gaztelurrutia, T.; Munguira, A.; Sánchez-Lavega, A.; Toledo, D.; Apéstigue, V.; Arruego, I.; Vicente-Retortillo, A.; Martínez, G.; Lemmon, M.; Lorenz, R.; Richardson, M.; Viudez-Moreiras, D.; de la Torre-Juarez, M.; Rodríguez-Manfredi, J. A.; Tamppari, L. K.; Murdoch, N.; Navarro-López, S.; Gómez-Elvira, J.; Baker, M.; Pla-García, J.; Harri, A. M.; Hieta, M.; Genzer, M.; Polkko, J.; Jaakonaho, I.; Makinen, T.; Stott, A.; Mimoun, D.; Chide, B.; Sebastian, E.; Banfield, D.; Lepinette-Malvite, A. |
| Affiliation: | AA(Física Aplicada, Escuela de Ingeniería de Bilbao, Universidad del País Vasco UPV/EHU, Bilbao, Spain), AB(Aeolis Research, Chandler, AZ USA), AC(Física Aplicada, Escuela de Ingeniería de Bilbao, Universidad del País Vasco UPV/EHU, Bilbao, Spain), AD(Física Aplicada, Escuela de Ingeniería de Bilbao, Universidad del País Vasco UPV/EHU, Bilbao, Spain), AE(Física Aplicada, Escuela de Ingeniería de Bilbao, Universidad del País Vasco UPV/EHU, Bilbao, Spain), AF(Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain), AG(Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain), AH(Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain), AI(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AJ(Lunar and Planetary Institute, Houston, TX USA), AK(Space Science Institute, College Station, TX USA), AL(Johns Hopkins Applied Physics Laboratory, Laurel, MD USA), AM(Aeolis Research, Chandler, AZ USA), AN(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AO(Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA USA), AP(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AQ(Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA USA), AR(Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Université de Toulouse, Toulouse, France), AS(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AT(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AU(Smithsonian Institution, Washington, DC USA), AV(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AW(Finnish Meteorological Institute, Helsinki, Finland), AX(Finnish Meteorological Institute, Helsinki, Finland), AY(Finnish Meteorological Institute, Helsinki, Finland), AZ(Finnish Meteorological Institute, Helsinki, Finland), BA(Finnish Meteorological Institute, Helsinki, Finland), BB(Finnish Meteorological Institute, Helsinki, Finland), BC(Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Université de Toulouse, Toulouse, France), BD(Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Université de Toulouse, Toulouse, France), BE(Los Alamos National Laboratory, Los Alamos, NM USA), BF(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BG(Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY USA), BH(Centro de Astrobiología (INTA-CSIC), Madrid, Spain) |
| Journal: | Journal of Geophysical Research: Planets, Volume 128, Issue 2, article id. e2022JE007516. |
| Publication Date: | Feb 2023 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, dust sevils, Jezero, MEDA |
| Abstract Copyright: | 2023. The Authors. |
| DOI: | https://doi.org/10.1029/2022JE007516 |
| Bibliographic Code: | 2023JGRE..12807516H |
| Abstract: | We characterize vortex and dust devils (DDs) at Jezero from pressure and winds obtained with the Mars Environmental Dynamics Analyzer (MEDA) instrument on Mars 2020 over 415 Martian days (sols) (Ls = 6°-213°). Vortices are abundant (4.9 per sol with pressure drops >0.5 Pa correcting from gaps in coverage) and they peak at noon. At least one in every five vortices carries dust, and 75% of all vortices with ∆p > 2.0 Pa are dusty. Seasonal variability was small but DDs were abundant during a dust storm (Ls = 152°-156°). Vortices are more frequent and intense over terrains with lower thermal inertia favoring high daytime surface-to-air temperature gradients. We fit measurements of winds and pressure during DD encounters to models of vortices. We obtain vortex diameters that range from 5 to 135 m with a mean of 20 m, and from the frequency of close encounters we estimate a DD activity of 2.0-3.0 DDs km<SUP>-2</SUP> sol<SUP>-1</SUP>. A comparison of MEDA observations with a Large Eddy Simulation of Jezero at Ls = 45° produces a similar result. Three 100-m size DDs passed within 30 m of the rover from what we estimate that the activity of DDs with diameters >100 m is 0.1 DDs km<SUP>-2</SUP>sol<SUP>-1</SUP>, implying that dust lifting is dominated by the largest vortices in Jezero. At least one vortex had a central pressure drop of 9.0 Pa and internal winds of 25 ms<SUP>-1</SUP>. The MEDA wind sensors were partially damaged during two DD encounters whose characteristics we elaborate in detail. |
| Title: | The diverse meteorology of Jezero crater over the first 250 sols of Perseverance on Mars |
|---|---|
| Authors: | Rodriguez-Manfredi, J. A.; de la Torre Juarez, M.; Sanchez-Lavega, A.; Hueso, R.; Martinez, G.; Lemmon, M. T.; Newman, C. E.; Munguira, A.; Hieta, M.; Tamppari, L. K.; Polkko, J.; Toledo, D.; Sebastian, E.; Smith, M. D.; Jaakonaho, I.; Genzer, M.; De Vicente-Retortillo, A.; Viudez-Moreiras, D.; Ramos, M.; Saiz-Lopez, A.; Lepinette, A.; Wolff, M.; Sullivan, R. J.; Gomez-Elvira, J.; Apestigue, V.; Conrad, P. G.; Del Rio-Gaztelurrutia, T.; Murdoch, N.; Arruego, I.; Banfield, D.; Boland, J.; Brown, A. J.; Ceballos, J.; Dominguez-Pumar, M.; Espejo, S.; Fairén, A. G.; Ferrandiz, R.; Fischer, E.; Garcia-Villadangos, M.; Gimenez, S.; Gomez-Gomez, F.; Guzewich, S. D.; Harri, A.-M.; Jimenez, J. J.; Jimenez, V.; Makinen, T.; Marin, M.; Martin, C.; Martin-Soler, J.; Molina, A.; Mora-Sotomayor, L.; Navarro, S.; Peinado, V.; Perez-Grande, I.; Pla-Garcia, J.; Postigo, M.; Prieto-Ballesteros, O.; Rafkin, S. C. R.; Richardson, M. I.; Romeral, J.; Romero, C.; Savijärvi, H.; Schofield, J. T.; Torres, J.; Urqui, R.; Zurita, S.; MEDA Team |
| Affiliation: | AA(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AB(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA), AC(Dept. Fí sica Aplicada, Universidad del País Vasco (UPV/EHU), Bilbaoí, Spain), AD(Dept. Fí sica Aplicada, Universidad del País Vasco (UPV/EHU), Bilbaoí, Spain), AE(Lunar and Planetary Institute, Houston, TX, USA), AF(Space Science Institute, Boulder, CO, USA), AG(Aeolis Corporation, Sierra Madre, CA, USA), AH(Dept. Fí sica Aplicada, Universidad del País Vasco (UPV/EHU), Bilbaoí, Spain), AI(Finnish Meteorological Institute, Helsinki, Finland), AJ(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA), AK(Finnish Meteorological Institute, Helsinki, Finland), AL(Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain), AM(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AN(NASA Goddard Space Flight Center, Greenbelt, MD, USA), AO(Finnish Meteorological Institute, Helsinki, Finland), AP(Finnish Meteorological Institute, Helsinki, Finland), AQ(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AR(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AS(Dept. Física y Matemáticas, Universidad de Alcalá, Alcalá de Henares, Spain), AT(Institute of Physical Chemistry Rocasolano, CSIC, Madrid, Spain), AU(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AV(Space Science Institute, Boulder, CO, USA), AW(Cornell University, Ithaca, NY, USA), AX(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AY(Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain), AZ(Carnegie Institution, Washington, DC, USA), BA(Dept. Fí sica Aplicada, Universidad del País Vasco (UPV/EHU), Bilbaoí, Spain), BB(Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Université de Toulouse, Toulouse, France), BC(Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain), BD(NASA Ames Research Center, Mountain View, CA, USA), BE(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA), BF(Plancius Research, Severna Park, MD, USA), BG(Instituto de Microelectrónica de Sevilla (US-CSIC), Seville, Spain), BH(Dept. de Ingeniería Electrónica, Universidad Politécnica de Cataluña, Barcelona, Spain), BI(Instituto de Microelectrónica de Sevilla (US-CSIC), Seville, Spain), BJ(Centro de Astrobiología (INTA-CSIC), Madrid, Spain; Cornell University, Ithaca, NY, USA), BK(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BL(Dept. of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, USA), BM(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BN(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BO(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BP(NASA Goddard Space Flight Center, Greenbelt, MD, USA), BQ(Finnish Meteorological Institute, Helsinki, Finland), BR(Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain), BS(Dept. de Ingeniería Electrónica, Universidad Politécnica de Cataluña, Barcelona, Spain), BT(Finnish Meteorological Institute, Helsinki, Finland), BU(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BV(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BW(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BX(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BY(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BZ(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CA(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CB(Dept. de Mecánica de Fluidos y Propulsión Aeroespacial, Universidad Politécnica de Madrid, Madrid, Spain), CC(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CD(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CE(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CF(Southwest Research Institute, Boulder, CO, USA), CG(Aeolis Corporation, Sierra Madre, CA, USA), CH(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CI(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CJ(Finnish Meteorological Institute, Helsinki, Finland), CK(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA), CL(Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain), CM(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CN(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CO(Centro de Astrobiología (INTA-CSIC), Madrid, Spain; Dept. Física y Matemáticas, Universidad de Alcalá, Alcalá de Henares, Spain; Institute of Physical Chemistry Rocasolano, CSIC, Madrid, Spain; Cornell University, Ithaca, NY, USA; Carnegie Institution, Washington, DC, USA; Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Université de Toulouse, Toulouse, France; NASA Ames Research Center, Mountain View, CA, USA; Plancius Research, Severna Park, MD, USA; Instituto de Microelectrónica de Sevilla (US-CSIC), Seville, Spain; Dept. de Ingeniería Electrónica, Universidad Politécnica de Cataluña, Barcelona, Spain; Dept. of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, USA; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA; Dept. de Mecánica de Fluidos y Propulsión Aeroespacial, Universidad Politécnica de Madrid, Madrid, Spain; Southwest Research Institute, Boulder, CO, USA; Dept. Fí sica Aplicada, Universidad del País Vasco (UPV/EHU), Bilbaoí, Spain; Lunar and Planetary Institute, Houston, TX, USA; Space Science Institute, Boulder, CO, USA; Aeolis Corporation, Sierra Madre, CA, USA; Finnish Meteorological Institute, Helsinki, Finland; Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain; NASA Goddard Space Flight Center, Greenbelt, MD, USA) |
| Journal: | Nature Geoscience, Volume 16, Issue 1, p.19-28. |
| Publication Date: | Jan 2023 |
| Origin: | Springer Science and Business Media LLC |
| DOI: | https://doi.org/10.1038/s41561-022-01084-0 |
| Bibliographic Code: | 2023NatGe..16...19R |
| Abstract: | NASA's Perseverance rover's Mars Environmental Dynamics Analyzer is collecting data at Jezero crater, characterizing the physical processes in the lowest layer of the Martian atmosphere. Here we present measurements from the instrument's first 250 sols of operation, revealing a spatially and temporally variable meteorology at Jezero. We find that temperature measurements at four heights capture the response of the atmospheric surface layer to multiple phenomena. We observe the transition from a stable night-time thermal inversion to a daytime, highly turbulent convective regime, with large vertical thermal gradients. Measurement of multiple daily optical depths suggests aerosol concentrations are higher in the morning than in the afternoon. Measured wind patterns are driven mainly by local topography, with a small contribution from regional winds. Daily and seasonal variability of relative humidity shows a complex hydrologic cycle. These observations suggest that changes in some local surface properties, such as surface albedo and thermal inertia, play an influential role. On a larger scale, surface pressure measurements show typical signatures of gravity waves and baroclinic eddies in a part of the seasonal cycle previously characterized as low wave activity. These observations, both combined and simultaneous, unveil the diversity of processes driving change on today's Martian surface at Jezero crater. |
| Title: | Winds at the Mars 2020 Landing Site: 1. Near-Surface Wind Patterns at Jezero Crater |
|---|---|
| Authors: | Viúdez-Moreiras, D.; Lemmon, M.; Newman, C. E.; Guzewich, S.; Mischna, M.; Gómez-Elvira, J.; Herkenhoff, K.; Sánchez-Lavega, A.; de la Torre, M.; Rodríguez-Manfredi, J. A.; Lorenz, R. D.; Pla-García, J.; Hueso, R.; Richardson, M.; Tamppari, L.; Smith, M.; Apéstigue, V.; Toledo, D.; Bell, J. |
| Affiliation: | AA(Centro de Astrobiologia (CAB, CSIC-INTA) and National Institute for Aerospace Technology (INTA), Madrid, Spain), AB(Space Science Institute, College Station, TX USA), AC(Aeolis Research, Chandler, AZ USA), AD(NASA Goddard Spaceflight Center, Greenbelt, MD USA), AE(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AF(National Institute for Aerospace Technology (INTA), Madrid, Spain), AG(USGS Astrogeology Science Center, Flagstaff, AZ USA), AH(Universidad del País Vasco (UPV/EHU), Bilbao, Spain), AI(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AJ(Centro de Astrobiologia (CAB, CSIC-INTA) and National Institute for Aerospace Technology (INTA), Madrid, Spain), AK(Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA), AL(Centro de Astrobiologia (CAB, CSIC-INTA) and National Institute for Aerospace Technology (INTA), Madrid, Spain), AM(USGS Astrogeology Science Center, Flagstaff, AZ USA), AN(Aeolis Research, Chandler, AZ USA), AO(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AP(NASA Goddard Spaceflight Center, Greenbelt, MD USA), AQ(National Institute for Aerospace Technology (INTA), Madrid, Spain), AR(National Institute for Aerospace Technology (INTA), Madrid, Spain), AS(School of Earth and Space Exploration, Arizona State University, Tempe, AZ USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 127, Issue 12, article id. e2022JE007522. |
| Publication Date: | Dec 2022 |
| Origin: | American Geophysical Union (AGU) |
| Abstract Copyright: | 2022. The Authors. |
| DOI: | https://doi.org/10.1029/2022JE007522 |
| Bibliographic Code: | 2022JGRE..12707522V |
| Abstract: | This is the first part of a two-part paper. NASA's Mars 2020 Perseverance rover measured winds on the Jezero crater floor close to the delta of an ancient river. A mostly repeatable diurnal cycle was observed and presented two regimes: (a) a convective regime, from dawn to sunset, with average easterly to southeasterly winds, during which maximum wind speeds were measured, and (b) a nighttime regime with westerly-northwesterly winds followed by a relatively calm period with highly variable wind directions as a function of sol and time of night. The timing and magnitude of the observed regimes are consistent with primary control by regional and local slope flows. Data suggest that the surface circulation at Jezero region in northern spring and summer is highly unaffected by large-scale circulation except during particular periods in the diurnal cycle or generally during dust storms, which is supported by MarsWRF model simulations. Consequently, the observed seasonal variability was weak. However, sol-to-sol and seasonal variability were measured, most of it during certain nighttime periods. Traveling waves consistent with baroclinic instability were clearly observed in surface winds at L<SUB>s</SUB> ∼ 75°. The early MY36/2022A regional dust storm at L<SUB>s</SUB> ∼ 153° disturbed the wind patterns with changes suggesting enhanced tidal flows. After sunset, the dust storm also produced detectable gravity wave activity, increasing the mixing in the nighttime planetary boundary layer during storm conditions. Inferred wind directions from dust devil movies strongly suggest that prevailing winds continued to be slope-driven during the late summer, fall and early winter seasons. |
| Title: | Analyzing vertical dust distribution and associated meteorological characteristics over Acidalia Planitia during a regional and global dust event |
|---|---|
| Authors: | Guha, Bijay Kumar; Panda, Jagabandhu |
| Affiliation: | AA(National Space Science and Technology Center, United Arab Emirates University, Al Ain, Abu Dhabi, United Arab Emirates), AB(Department of Earth and Atmospheric Sciences, National Institute of Technology Rourkela, Odisha, India) |
| Journal: | Icarus, Volume 388, article id. 115230. |
| Publication Date: | Dec 2022 |
| Origin: | Elsevier BV |
| Keywords: | Mars atmosphere, Dust storm, Cloud, MarsWRF, EOF |
| Abstract Copyright: | (c) 2022 The Authors |
| DOI: | https://doi.org/10.1016/j.icarus.2022.115230 |
| Bibliographic Code: | 2022Icar..38815230G |
| Abstract: | This study analyzed the vertical distribution of dust and associated atmospheric structural changes over Acidalia Planitia during one regional dust event (RDE) (MY 32, Ls = 220°) and one global dust event (GDE) (MY 28, Ls = 260°), using Mars Climate Sounder observations and Mars Weather Research and Forecasting (MarsWRF) model simulations. Multilinear Regression Coefficient (MLRC) analysis suggests that dustiness at 25-35 km and ~ 40-50 km altitudes contributed significantly to the column integrated opacity during the RDE and GDE, respectively. Both dust events reduced water ice opacity at ~40 km altitude. The atmosphere subsequently warmed ~10 K during the RDE and ~ 30 K during the GDE because of dust radiative heating. An inversion layer formed below ~20 km altitude during RDE due to the combined effect of reduced surface temperature and the downwelling radiation from suspended dust. However, the GDE's much larger opacity at higher altitudes helped form a similar inversion layer at 40 km. This atmospheric warming with the inversion layer below could be associated with heating/cooling layers centered around 35-50 and 20-35 km heights, influencing the variability of water ice within them. The MarsWRF simulations showed downwelling over Acidalia Planitia at ~35-50 km altitude, which supports the presence of the heating layer due to the suspended atmospheric dust during the GDE. However, findings from the heating rate analysis indicated a dominance of dust radiative heating compared to adiabatic heating due to compression on the atmospheric warming during the dust storm occurrences. The simulated boundary layer height and surface radiation flux suggest weaker vertical mixing from the surface and a surface energy budget dominated by downward radiation from the suspended dust, which helped form heating/cooling layers and drove variability in water ice clouds. The Empirical Orthogonal Function analysis (carried out using MCS observations) suggests that the seasonal cycle of the southern hemispheric dust storms, northern hemispheric active storm track, and the cap-edge storms possibly influenced the seasonality observed in the heating/cooling layer clouds. |
| Title: | The Effect of Model Resolution on the Vertical and Temporal Variation in the Simulated Martian Climate |
|---|---|
| Authors: | Zhou, Yu-Wei; Chow, Kim-Chiu; Xiao, Jing |
| Affiliation: | AA(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau 999078, China), AB(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau 999078, China; CNSA Macau Center for Space Exploration and Science, Macau 999078, China;), AC(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau 999078, China; CNSA Macau Center for Space Exploration and Science, Macau 999078, China) |
| Journal: | Atmosphere, Volume 13, Issue 10, id.1736. |
| Publication Date: | Oct 2022 |
| Origin: | MDPI AG |
| Keywords: | Mars, general circulation model, dust lifting, MarsWRF, model resolution |
| DOI: | https://doi.org/10.3390/atmos13101736 |
| Bibliographic Code: | 2022Atmos..13.1736Z |
| Abstract: | To study the impact of model horizontal resolution on the simulated climate of Mars, we increased the model resolution of the Mars general circulation model MarsWRF from the commonly used 5° × 5° (standard resolution, SR) to 3° × 3° (high resolution, HR). We applied an interactive dust scheme to parameterize the dust-lifting process and investigated the effect of model resolution from three aspects: (1) temporal variation; (2) horizontal distribution; and (3) vertical distribution. From the results of the simulations, we obtained the following conclusions: (1) The seasonal variation in some zonal-mean fields such as the column optical depth and T15 temperature could be reasonably simulated in both the SR and HR simulations, and the results were similar. (2) The effect of resolution on the horizontal distribution of the climate fields was significant at some regions with complicated terrain. (3) The HR simulation could be different from the SR simulation in the vertical dynamic field and thermal field. To obtain more accurate simulation results, it is recommended to use a higher resolution simulation when the vertical distribution is a major concern in the study. |
| Title: | Connections between the Transient Polar Warming and Solstitial Pause on Mars |
|---|---|
| Authors: | Toigo, Anthony D.; Waugh, Darryn W. |
| Affiliation: | AA(Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA), AB(Department of Earth and Planetary Science, Johns Hopkins University, Baltimore, MD 21218, USA) |
| Journal: | The Planetary Science Journal, Volume 3, Issue 9, id.208, <NUMPAGES>18</NUMPAGES> pp. |
| Publication Date: | Sep 2022 |
| Origin: | American Astronomical Society |
| Keywords: | Planetary atmospheres, Planetary science, Atmospheric science, Planetary climates, Mars, 1244, 1255, 116, 2184, 1007 |
| DOI: | https://doi.org/10.3847/PSJ/ac8550 |
| Bibliographic Code: | 2022PSJ.....3..208T |
| Abstract: | Observations show two different transient atmospheric events around the northern winter solstice on Mars: a warming of the polar lower atmosphere (100-10 Pa) and a reduction in the near-surface wave activity. Here we examine the cause of, and connections between, these two events, and how their occurrence may have changed in past climates using a suite of Mars general circulation model simulations. These simulations show that the polar warming and pause in wave activity are connected, and they occur when there are sufficiently large dust heating rates in the southern (summer) high latitudes, which drive an expansion of the downwelling branch of the Hadley cell into the northern polar region. This causes a poleward shift and weakening of the jet, a warming of the polar lower atmosphere, and reduced baroclinic instability and waves near the surface. The occurrence and strength of the polar warming and wave activity pause increase with obliquity and dust optical depth, with a stronger dependence on obliquity. In past climates with low obliquity the warming and pause are unlikely to occur, or will be very weak, whereas during times of high obliquity they will likely be strong and occur every winter, unless the atmosphere is nearly free of dust. |
| Title: | Simulation of dust activities in the southern high latitudes of Mars |
|---|---|
| Authors: | Chow, Kim-Chiu; Xiao, Jing; Wang, Ye-Meng |
| Affiliation: | AA(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau, PR China), AB(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau, PR China), AC(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau, PR China) |
| Journal: | Planetary and Space Science, Volume 217, article id. 105492. |
| Publication Date: | Aug 2022 |
| Origin: | Elsevier BV |
| Keywords: | Mars, Cap-edge dust, Sublimation flow, Dust lifting |
| Abstract Copyright: | (c) 2022 Elsevier Ltd |
| DOI: | https://doi.org/10.1016/j.pss.2022.105492 |
| Bibliographic Code: | 2022P&SS..21705492C |
| Abstract: | Annual occurrence of dust activities in the southern high-latitude region around the southern solstice period have been observed for many Martian years. Theses dust events occur near the southern cap-edge region and play an important role in the observed dust climate. However, they generally cannot be simulated in the existing Mars general circulation models. In this study, an approach of parameterization has been applied to the Mars climate model MarsWRF in which the dust lifting threshold stress is adjusted in according to the surface temperature difference between the regolith and the ice in the southern polar region. By this approach, dust events in the southern cap-edge region have been simulated around the southern solstice period. As a result, the simulated temperature in the southern high-latitude region is increased and the resulting vertical temperature profile is closer to that from observation. In addition, westward propagating dust events as observed in a previous study have been simulated, with a propagating speed similar to that observed. Results of the numerical experiments suggest that the flow associated with the sublimation of the CO<SUB>2</SUB> ice in the southern cap edge is important to the occurrence and propagation of these dust events in this region. |
| Title: | The Aeolian Environment in Glen Torridon, Gale Crater, Mars |
|---|---|
| Authors: | Sullivan, R.; Baker, M.; Newman, C.; Turner, M.; Schieber, J.; Weitz, C.; Hallet, B.; Ellison, D.; Minitti, M. |
| Affiliation: | AA(CCAPS, Cornell University, Ithaca, NY USA), AB(Center for Earth & Planetary Studies, National Air & Space Museum, Smithsonian Institution, Washington, DC USA), AC(Aeolis Research, Pasadena, CA USA), AD(The Johns Hopkins University Morton K. Blaustein Department of Earth and Planetary Sciences, Baltimore, MD USA), AE(Department of Geological Sciences, Indiana University, Bloomington, IN USA), AF(Planetary Science Institute, Tucson, AZ USA), AG(University of Washington, Seattle, WA USA), AH(Jet Propulion Laboratory, Pasadena, CA USA), AI(Framework, Silver Spring, MD USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 127, Issue 8, article id. e07174. |
| Publication Date: | Aug 2022 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, aeolian, Glen Torridon |
| Abstract Copyright: | 2022. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2021JE007174 |
| Bibliographic Code: | 2022JGRE..12707174S |
| Abstract: | The Mars Science Laboratory (MSL) rover spent a full martian year exploring the phyllosilicate-bearing Glen Torridon trough on the flank of Aeolis Mons in Gale crater, enabling in-depth assessment of aeolian processes. MSL encountered erosional and depositional features recording a long aeolian history. The trough has served as a long-term conduit for sand transport, probably involving many cycles of sand accumulation and deflation. Rock abrasion textures indicate sand-driving winds blowing W-SW (opposite of abrasion textures on the Greenheugh Pediment above the trough floor). Indurated megaripple surfaces with 2-5 mm grains contrast with seasonally active ripples having finer maximum grain sizes, indicating more vigorous saltation in the past. Active ripples display a broad continuum of wavelengths, as well as coarser grains at crests than troughs, consistent with origins as impact ripples. Orientations of a wind streak extending from a large ripple field, and sandy wind tails behind obstacles, indicate sand is driven W-SW in the current era, approximately along the trough axis. Erosion of drill tailings piles was strongly seasonal, enhanced during late spring and early summer (perihelion). Climate modeling suggests W-SW sand transport can be attributed to seasonal enhancement of nighttime regional winds entering Gale crater from the N, combined with local katabatic winds flowing down the slopes of Aeolis Mons. However, it is unclear whether sand transport at Glen Torridon is primarily from these wind components combining and acting simultaneously, or occurring in serial at different times of night; field evidence supports both possibilities. |
| Title: | Multi-year measurements of ripple and dune migration on Mars: Implications for the wind regime and sand transport |
|---|---|
| Authors: | Roback, Kevin P.; Runyon, Kirby; Newman, Claire; Avouac, Jean-Philippe |
| Affiliation: | AA(California Institute of Technology, Division of Geological and Planetary Sciences, Pasadena, CA, USA), AB(The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA), AC(Aeolis Research, Tucson, AZ, USA), AD(California Institute of Technology, Division of Geological and Planetary Sciences, Pasadena, CA, USA) |
| Journal: | Icarus, Volume 380, article id. 114966. |
| Publication Date: | Jul 2022 |
| Origin: | Elsevier BV |
| Keywords: | Mars, Aeolian geomorphology, Sand transport, Mars climate, Image correlation |
| Abstract Copyright: | (c) 2022 Elsevier Science B.V. All rights reserved. |
| DOI: | https://doi.org/10.1016/j.icarus.2022.114966 |
| Bibliographic Code: | 2022Icar..38014966R |
| Abstract: | Aeolian sand dunes are observed across the Martian surface. The arrival of the HiRISE camera on Mars Reconnaissance Orbiter at Mars in 2006 enabled detection of modern-day movement of dunes and ripples from orbit for the first time. Since 2006, HiRISE collected a long timeseries of repeat imagery at a few Martian dune fields. We analyze this timeseries of imagery at two of these dune fields, using COSI-Corr for image registration and correlation, to study the movement and dynamics of dunes and meter-scale ripples at the Nili Patera and Meroe Patera barchan dune fields. We present measurements of whole-dune translational sand fluxes extracted at both dune fields via manual tracking of dune crestlines and slipfaces in HiRISE images. We also present a multi-Mars year timeseries of ripple flux measurements. Ripple migration shows a consistent pattern of seasonal variation, with maxima in flux during northern-hemisphere autumn and winter at both dune fields. Ripple migration is also observed to decrease away from the upwind margins of dune fields. We compare our observations with predicted sand transport using winds output from the MarsWRF atmospheric circulation model and theories of sand motion. The model predicts half-hourly, mesoscale winds, from which we estimate the 1 Hz, local-scale winds by assuming a Weibull distribution of wind speed, with parameters chosen based on landed wind data. This approach uses remote sensing observations of bedform migration, and comparisons with model output, to place constraints on the wind regime. Our measurements of the seasonal pattern of sand flux variation agree, to first order, with predictions based on modeled wind speeds. Comparison of the magnitudes of predicted and observed sand fluxes is not feasible due to the high uncertainties in our calculated sand fluxes caused by uncertainties in input parameters, most importantly the assumed fluid threshold for sand transport. However, we note that model predictions fit our observed sand fluxes best when relatively low values of the fluid threshold shear velocity of ~0.6-0.8 m/s (or shear stresses of O(10<SUP>-3</SUP>) Pa) are assumed. |
| Title: | Earth-like thermal and dynamical coupling processes in the Martian climate system |
|---|---|
| Authors: | Wu, Zhaopeng; Li, Tao; Heavens, Nicholas G.; Newman, Claire E.; Richardson, Mark I.; Yang, Chengyun; Li, Jing; Cui, Jun |
| Affiliation: | AA(Planetary Environmental and Astrobiological Research Laboratory, School of Atmospheric Sciences, Sun Yat-Sen University, Zhuhai, Guangdong, 519082, China), AB(CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, China), AC(Department of Earth Science and Engineering, Imperial College, London, UK), AD(Aeolis Research, Chandler, AZ, USA), AE(Aeolis Research, Chandler, AZ, USA), AF(CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, China), AG(Planetary Environmental and Astrobiological Research Laboratory, School of Atmospheric Sciences, Sun Yat-Sen University, Zhuhai, Guangdong, 519082, China), AH(Planetary Environmental and Astrobiological Research Laboratory, School of Atmospheric Sciences, Sun Yat-Sen University, Zhuhai, Guangdong, 519082, China) |
| Journal: | Earth Science Reviews, Volume 229, article id. 104023. |
| Publication Date: | Jun 2022 |
| Origin: | Elsevier BV |
| Abstract Copyright: | (c) 2022 Elsevier Science B.V. All rights reserved. |
| DOI: | https://doi.org/10.1016/j.earscirev.2022.104023 |
| Bibliographic Code: | 2022ESRv..22904023W |
| Abstract: | The burst of Mars exploration in the past two decades has significantly improved our knowledge of the Martian atmosphere. A variety of complementary, multiannual observational records have revealed Earth-like cycling of dust and water through the Mars system, as well as hints of dynamical coupling between the lower, middle, and upper atmosphere involving deep convection, planetary waves, thermal tides, and gravity waves that can be analogous to, but sometimes very different from, coupling processes in the Earth's atmosphere. This review focuses on several essential coupling processes on Mars involving the dust/water cycling and wave activity: (1) interaction between the dust cycle, water cycle and wave activity in the lower atmosphere; (2) the global meridional circulation and middle atmospheric polar warmings; and (3) vertical coupling throughout the atmosphere during dusty/non-dusty conditions. Most of these processes have been studied with state-of-the-art numerical models validated with recent observations. In addition, we summarize several newly proposed hypotheses that potentially impact our understanding of major issues in planetary science such as atmospheric coupling, water escape, or mesospheric cloud formation. We find many similarities between wave-induced couplings on Earth and Mars and analogies between the Earth's water cycle and Mars's dust cycle, which provide insights into comparative studies of these two planets. |
| Title: | Orbital and In-Situ Investigation of Periodic Bedrock Ridges in Glen Torridon, Gale Crater, Mars |
|---|---|
| Authors: | Stack, Kathryn M.; Dietrich, William E.; Lamb, Michael P.; Sullivan, Robert J.; Christian, John R.; Newman, Claire E.; O'Connell-Cooper, Catherine D.; Sneed, Jonathan W.; Day, Mackenzie; Baker, Mariah; Arvidson, Raymond E.; Fedo, Christopher M.; Khan, Sabrina; Williams, Rebecca M. E.; Bennett, Kristen A.; Bryk, Alexander B.; Cofield, Shannon; Edgar, Lauren A.; Fox, Valerie K.; Fraeman, Abigail A.; House, Christopher H.; Rubin, David M.; Sun, Vivian Z.; Van Beek, Jason K. |
| Affiliation: | AA(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AB(Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA USA), AC(Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA USA), AD(Cornell Center for Astrophysics & Planetary Science, Cornell University, Ithaca, NY USA), AE(Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO USA), AF(Aeolis Research, Chandler, AZ USA), AG(Department of Earth Science, University of New Brunswick, Fredericton, NB Canada), AH(Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, CA USA), AI(Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, CA USA), AJ(Center for Earth & Planetary Studies, National Air & Space Museum, Smithsonian Institution, Washington, DC USA), AK(Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO USA), AL(Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, Knoxville, TN USA), AM(Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA USA), AN(Planetary Science Institute, Tucson, AZ USA), AO(Astrogeology Science Center, U.S. Geological Survey, Flagstaff, AZ USA), AP(Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA USA), AQ(U.S. Department of the Interior, Bureau of Ocean Energy Management, Washington, DC USA), AR(Astrogeology Science Center, U.S. Geological Survey, Flagstaff, AZ USA), AS(Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN USA), AT(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AU(College of Earth and Mineral Sciences, Penn State University, University Park, PA USA), AV(Earth and Planetary Sciences, University of California, Santa Cruz, Santa Cruz, CA USA), AW(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AX(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 127, Issue 6, article id. e07096. |
| Publication Date: | Jun 2022 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | periodic bedrock ridges, Mars Science Laboratory, Gale crater, Glen Torridon, aeolian processes |
| Abstract Copyright: | 2022 Jet Propulsion Laboratory. California Institute of Technology. Government sponsorship acknowledged. |
| DOI: | https://doi.org/10.1029/2021JE007096 |
| Bibliographic Code: | 2022JGRE..12707096S |
| Abstract: | Gale crater, the field site for NASA's Mars Science Laboratory Curiosity rover, contains a diverse and extensive record of aeolian deposition and erosion. This study focuses on a series of regularly spaced, curvilinear, and sometimes branching bedrock ridges that occur within the Glen Torridon region on the lower northwest flank of Aeolis Mons, the central mound within Gale crater. During Curiosity's exploration of Glen Torridon between sols ∼2300-3080, the rover drove through this field of ridges, providing the opportunity for in situ observation of these features. This study uses orbiter and rover data to characterize ridge morphology, spatial distribution, compositional and material properties, and association with other aeolian features in the area. Based on these observations, we find that the Glen Torridon ridges are consistent with an origin as wind-eroded bedrock ridges, carved during the exhumation of Mount Sharp. Erosional features like the Glen Torridon ridges observed elsewhere on Mars, termed periodic bedrock ridges (PBRs), have been interpreted to form transverse to the dominant wind direction. The size and morphology of the Glen Torridon PBRs are consistent with transverse formative winds, but the orientation of nearby aeolian bedforms and bedrock erosional features raise the possibility of PBR formation by a net northeasterly wind regime. Although several formation models for the Glen Torridon PBRs are still under consideration, and questions persist about the nature of PBR-forming paleowinds, the presence of PBRs at this site provides important constraints on the depositional and erosional history of Gale crater. |
| Title: | Changing spatial distribution of water flow charts major change in Mars's greenhouse effect |
|---|---|
| Authors: | Kite, Edwin S.; Mischna, Michael A.; Fan, Bowen; Morgan, Alexander M.; Wilson, Sharon A.; Richardson, Mark I. |
| Journal: | Science Advances, vol. 8, issue 21, id. eabo5894. |
| Publication Date: | May 2022 |
| Origin: | American Association for the Advancement of Science (AAAS) |
| Keywords: | Astrophysics - Earth and Planetary Astrophysics, Physics - Atmospheric and Oceanic Physics, Physics - Geophysics |
| DOI: | https://doi.org/10.1126/sciadv.abo5894 |
| Bibliographic Code: | 2022SciA....8O5894K |
| Abstract: | Early Mars had rivers, but the cause of Mars's wet-to-dry transition remains unknown. Past climate on Mars can be probed using the spatial distribution of climate-sensitive landforms. We analyzed global databases of water-worked landforms and identified changes in the spatial distribution of rivers over time. These changes are simply explained by comparison to a simplified meltwater model driven by an ensemble of global climate model simulations, as the result of ≳10 K global cooling, from global average surface temperature T ̄ ≥ 268 K to T ̄ ~ 258 K, due to a weaker greenhouse effect. In other words, river-forming climates on early Mars were warm and wet first, and cold and wet later. Unexpectedly, analysis of the greenhouse effect within our ensemble of global climate model simulations suggests that this shift was primarily driven by waning non-CO 2 radiative forcing, and not changes in CO 2 radiative forcing. Climates on early Mars were warm and wet first, and cold and wet later, likely due to waning non-CO 2 radiative forcing. |
| Title: | Winter Weakening of Titan's Stratospheric Polar Vortices |
|---|---|
| Authors: | Shultis, J.; Waugh, D. W.; Toigo, A. D.; Newman, C. E.; Teanby, N. A.; Sharkey, J. |
| Affiliation: | AA(Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21210, USA), AB(Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21210, USA), AC(Johns Hopkins Applied Physics Laboratory, MD, USA), AD(Aeolis Research, USA), AE(School of Earth Sciences, University of Bristol, Bristol, UK), AF(School of Earth Sciences, University of Bristol, Bristol, UK) |
| Journal: | The Planetary Science Journal, Volume 3, Issue 4, id.73, <NUMPAGES>11</NUMPAGES> pp. |
| Publication Date: | Apr 2022 |
| Origin: | American Astronomical Society |
| Keywords: | Atmospheric science, Planetary atmospheres, Atmospheric circulation, Titan, Saturnian satellites, Stratosphere, 116, 1244, 112, 2186, 1427, 1640 |
| DOI: | https://doi.org/10.3847/PSJ/ac5ea1 |
| Bibliographic Code: | 2022PSJ.....3...73S |
| Abstract: | Polar vortices are a prominent feature in Titan's stratosphere. The Cassini mission has provided a detailed view of the breakdown of the northern polar vortex and formation of the southern vortex, but the mission did not observe the full annual cycle of the evolution of the vortices. Here we use a TitanWRF general circulation model simulation of an entire Titan year to examine the full annual cycle of the polar vortices. The simulation reveals a winter weakening of the vortices, with a clear minimum in polar potential vorticity and midlatitude zonal winds between winter solstice and spring equinox. The simulation also produces the observed postfall equinox cooling followed by rapid warming in the upper stratosphere. This warming is due to strong descent and adiabatic heating, which also leads to the formation of an annular potential vorticity structure. The seasonal evolution of the polar vortices is very similar in the two hemispheres, with only small quantitative differences that are much smaller than the seasonal variations, which can be related to Titan's orbital eccentricity. This suggests that any differences between observations of the northern hemisphere vortex in late northern winter and the southern hemisphere vortex in early winter are likely due to the different observation times with respect to solstice, rather than fundamental differences in the polar vortices. |
| Title: | Characteristics of Dust Devils in Two Pre-Selected Landing Regions of the Tianwen-1 Mission—Comparing Observations and Predictions Using Numerical Model |
|---|---|
| Authors: | Wang, Ye-Meng; Chow, Kim-Chiu; Xiao, Jing; Xu, Yi |
| Affiliation: | AA(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau 999078, China;), AB(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau 999078, China; China National Space Administration (CNSA), Macau Center for Space Exploration and Science, Macau 999078, China;), AC(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau 999078, China; China National Space Administration (CNSA), Macau Center for Space Exploration and Science, Macau 999078, China), AD(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau 999078, China; China National Space Administration (CNSA), Macau Center for Space Exploration and Science, Macau 999078, China;) |
| Journal: | Remote Sensing, Volume 14, Issue 9, id.2117. |
| Publication Date: | Apr 2022 |
| Origin: | MDPI AG |
| Keywords: | dust devils, CTX, MarsWRF, Tianwen-1, Utopia Planitia |
| DOI: | https://doi.org/10.3390/rs14092117 |
| Bibliographic Code: | 2022RemS...14.2117W |
| Abstract: | The spatial and temporal distribution of dust devils (DDs) in the two pre-selected landing regions (ZA and ZB) of the Tianwen-1 mission in southern Utopia Planitia have been investigated by using images from the Context Camera (CTX) of the Mars Reconnaissance Orbiter (MRO). From the images of the regions in 8 Martian years, no DD was found in ZA, while 77 DDs were found in ZB. The observed DDs are mainly distributed in the northeastern part of ZB. The temporal variation in the observed DDs shows a prominent two-peak pattern in their local early spring and late summer. The size and height of the observed DDs have also been evaluated from the images, and they show a similar temporal variation as the occurrence. To investigate the possible conditions pertinent to these observed patterns of DD distribution, some analysis based on the thermodynamic theory of heat engines was performed using the output of the Mars climate model, MarsWRF. The spatial and temporal distribution of the simulated DDs are generally consistent with the observation, with significantly more DDs in ZB. Analysis of the model results suggests that the spatial distributions of the predicted DDs are mainly related to the distribution of sensible heat flux, which, in turn, is mainly determined by the surface-to-air temperature difference. The difference in DDs between ZA and ZB (more DDs in ZB) is dominated by the difference in sensible heat flux, which, in turn, is mainly related to the spatial variation of surface albedo. |
| Title: | Characteristics of convective vortices and dust devils at gale crater on Mars during MY33 |
|---|---|
| Authors: | Uttam, Shefali; Sheel, Varun; Singh, D.; Newman, C. E.; Lemmon, M. T. |
| Affiliation: | AA(Physical Research Laboratory, Navarangpura, Ahmedabad, 380009, India), AB(Physical Research Laboratory, Navarangpura, Ahmedabad, 380009, India), AC(Physical Research Laboratory, Navarangpura, Ahmedabad, 380009, India), AD(Aeolis Research, Pasadena, CA, USA), AE(Space Science Institute, Boulder, USA) |
| Journal: | Planetary and Space Science, Volume 213, article id. 105430. |
| Publication Date: | Apr 2022 |
| Origin: | Elsevier BV |
| Keywords: | Martian atmosphere, Convective vortex, Dust devils |
| Abstract Copyright: | (c) 2022 Elsevier Ltd |
| DOI: | https://doi.org/10.1016/j.pss.2022.105430 |
| Bibliographic Code: | 2022P&SS..21305430U |
| Abstract: | Convective vortices that are dust laden (dust devils), are believed to be an efficient mechanism for particle entrainment in the Martian atmosphere. Such vortices can be identified in-situ by landers or rovers by the reduced surface pressure when they pass by the instrument. We analyse data from the Rover Environmental Monitoring Station (REMS) on-board the Mars Science Laboratory (MSL) rover Curiosity during mission sols 1019 to 1686 (corresponding to Martian Year (MY) 33). We identified 611 short pressure drops that likely indicate the passage of convective vortices in vicinity of the rover. The cumulative power-law analysis of the detected pressure drops suggests a low abundance of stronger pressure drop events at the MSL site as compared to the Pathfinder and Phoenix sites. The reason for this can be attributed to the smaller boundary layer height at Gale crater. The power-law slope is smaller for MY 33 as compared to previous years, suggesting that the dust devil activity also increased inside the Gale crater with the progressing year. Among all vortices detected, 63 vortices (∼10%) also show a simultaneous drop in ultraviolet intensity, which signifies obscuration of sunlight by the dust-laden vortices. A seasonal study for dust devils occurrences based on UV flux data shows an increase in their frequency during the local southern summer season. A majority of our estimated tangential wind velocities are well below the Martian dust lifting threshold. This indicates that either the vortices passed far from the measuring instrument or that the threshold being used is higher than the actual threshold on Mars. |
| Title: | Diurnal Variability in Aeolian Sediment Transport at Gale Crater, Mars |
|---|---|
| Authors: | Baker, Mariah M.; Newman, Claire E.; Sullivan, Robert; Minitti, Michelle E.; Edgett, Kenneth S.; Fey, Deirdra; Ellison, Doug; Lewis, Kevin W. |
| Affiliation: | AA(Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington, DC USA; Morton K. Blaustein Department of Earth and Planetary Sciences, The Johns Hopkins University, Baltimore, MD USA), AB(Aeolis Research, Pasadena, CA USA), AC(Department of Astronomy, Cornell University, Ithaca, NY USA), AD(Framework, Silver Spring, MD USA), AE(Malin Space Science Systems, San Diego, CA USA), AF(Malin Space Science Systems, San Diego, CA USA), AG(NASA's Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AH(Morton K. Blaustein Department of Earth and Planetary Sciences, The Johns Hopkins University, Baltimore, MD USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 127, Issue 2, article id. e06734. |
| Publication Date: | Feb 2022 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | aeolian activity, saltation dynamics, Martian circulation patterns, Gale crater, Mars, curiosity rover |
| Abstract Copyright: | 2022. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2020JE006734 |
| Bibliographic Code: | 2022JGRE..12706734B |
| Abstract: | A suite of high resolution cameras onboard the Mars Science Laboratory (MSL) Curiosity rover have provided an unparalleled look at active aeolian processes on Mars, including within the first active dune field explored on another planet, the Bagnold Dunes. Here we present results from a subset of MSL's repeat imaging ("change detection") experiments with temporal resolutions sufficient to probe the diurnal variability in winds within Gale crater. Images reveal that saltation is a near-daily phenomenon during southern summer, with repeatable diurnal circulation patterns producing steady impact ripple migration toward the west/southwest. Nighttime fluxes are inferred to be ∼four times larger than daytime fluxes, consistent with predictions from the MarsWRF model of multiple periods of enhanced wind between sunset and sunrise. Multiple factors are likely facilitating saltation at this time: (a) time-averaged nighttime winds have a higher degree of variance (i.e., higher peak friction speeds) than daytime winds, (b) interactions between regional Hadley flows and local, thermally driven slope winds cause increased turbulence at night, and (c) relatively higher atmospheric density produces correspondingly higher shear stresses and decreases critical thresholds. Observations of sand transport at a range of spatiotemporal scales (down to scale of individual particles moving on the timescale of seconds) support the idea that bedform migration is driven by intermittent, low-flux saltation events when winds fluctuate between canonical impact and fluid thresholds. Yet, whereas gustiness may play a role in initiating transport, saltation is found to be highly predictable on diurnal timescales and is only stochastic on the shortest timescales characteristic of turbulent fluctuations in wind. |
| Title: | Simulation of Martian Dust Effects on Polar CO<SUB>2</SUB> Ice Caps and Atmospheric Circulation Using the MarsWRF Model |
|---|---|
| Authors: | Zhao, Yang; Zhong, Lei; Yuan, Renming; Zhao, Chun; Li, Rui; Wang, Yu; Lian, Yuan; Richardson, Mark |
| Affiliation: | AA(School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China), AB(School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China; CAS Center for Excellence in Comparative Planetology, Hefei, China; Frontiers Science Center for Planetary Exploration and Emerging Technologies, University of Science and Technology of China, Hefei, China), AC(School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China; Frontiers Science Center for Planetary Exploration and Emerging Technologies, University of Science and Technology of China, Hefei, China), AD(School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China; CAS Center for Excellence in Comparative Planetology, Hefei, China; Frontiers Science Center for Planetary Exploration and Emerging Technologies, University of Science and Technology of China, Hefei, China), AE(School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China; CAS Center for Excellence in Comparative Planetology, Hefei, China; Frontiers Science Center for Planetary Exploration and Emerging Technologies, University of Science and Technology of China, Hefei, China), AF(School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China; CAS Center for Excellence in Comparative Planetology, Hefei, China; Frontiers Science Center for Planetary Exploration and Emerging Technologies, University of Science and Technology of China, Hefei, China), AG(Aeolis Research, Chandler, AZ USA), AH(Aeolis Research, Chandler, AZ USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 126, Issue 12, article id. e06937. |
| Publication Date: | Dec 2021 |
| Origin: | American Geophysical Union (AGU) |
| Abstract Copyright: | 2021. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2021JE006937 |
| Bibliographic Code: | 2021JGRE..12606937Z |
| Abstract: | Martian dust plays an important role in modulating climate. However, the effects of dust on polar CO<SUB>2</SUB> ice caps, atmospheric circulation processes and the relationship between them are not yet clear. In this study, a Mars general circulation model (MarsWRF) was applied to investigate the impacts of the magnitude and timing of Martian dust storms on the spatiotemporal characteristics of polar CO<SUB>2</SUB> ice caps and atmospheric circulation. The results show that dust can inhibit the sublimation of southern CO<SUB>2</SUB> ice through the radiation effect. Under the "High Dust" scenario, the ice edge can extend up to 5° more equatorward than that under the "Standard" scenario around Ls = 220°. The extent of northern CO<SUB>2</SUB> ice cap is hardly affected by dust because the impacts induced by dust mainly appear north of 80°N. By shifting the timing of maximum dust loading during the dust season, the "Early Dust" scenario inhibits the sublimation of the southern ice cap, while the "Late Dust" scenario accelerates the sublimation process. In addition, the variations in dust loading strength can lead to changes in three near-surface wind belts, which are related to intensified Hardly circulation. The appearance of the warming vortex under the "Early Dust" scenario is delayed, and its intensity is 60 K lower than that observed in the "High Dust" and "Late Dust" scenarios. When dust loading increases, the northern CO<SUB>2</SUB> condensation process in the Western Hemisphere accelerates, which is due to the increased pole-to-equator temperature gradient and the increased meridional wind speed. |
| Title: | Dust and water ice variability and their interaction pattern during Martian low-dust and high-dust periods |
|---|---|
| Authors: | Guha, Bijay Kumar; Panda, Jagabandhu; Newman, Claire E.; Richardson, Mark I. |
| Affiliation: | AA(Department of Earth and Atmospheric Sciences, National Institute of Technology Rourkela, Odisha, 769008, India), AB(Department of Earth and Atmospheric Sciences, National Institute of Technology Rourkela, Odisha, 769008, India), AC(Aeolis Research, 333 N, Dobson Road, Unit 5, Chandler, AZ, 85224, USA), AD(Aeolis Research, 333 N, Dobson Road, Unit 5, Chandler, AZ, 85224, USA) |
| Journal: | Planetary and Space Science, Volume 209, article id. 105357. |
| Publication Date: | Dec 2021 |
| Origin: | Elsevier BV |
| Keywords: | Mars atmosphere, Dust, Water ice, MCS, MarsWRF |
| Abstract Copyright: | (c) 2021 Elsevier Ltd |
| DOI: | https://doi.org/10.1016/j.pss.2021.105357 |
| Bibliographic Code: | 2021P&SS..20905357G |
| Abstract: | Analysis of dust and water ice variation is carried out using observations from the Mars Climate Sounder (MCS), which includes the data for six years (during Martian years 29-34). This study only used the nighttime observations, as these profiles extend closer to the surface compared to the daytime. The correlation between dust opacity and water ice opacity is found to switch sign between the low-dust northern spring and summer (L<SUB>S</SUB> = 0°-180°) and high-dust southern spring and summer seasons (L<SUB>S</SUB> = 180°-360°). Density-scaled opacity profiles show the correlation between dust and water ice variability over the southern hemisphere and the tropics, which alters between 20 and 40 km altitudes. The positive correlation during the low-dust period over the latitudes 40-80°S is mainly controlled by the water ice cycle in the south polar hood clouds. Whereas the water ice cycle within the tropical cloud belt (TCB) serves as a primary controlling factor, and the presence of atmospheric dust prevails only in its formation stage within the latitudes -20 - 40°N. During the high-dust period, at southern latitudes, significant dust lifting and the associated temperature change are found to be the reason for the strong negative correlation with ice clouds. And in tropical latitudes, the significant positive relationship at relatively high altitudes (∼40 km) is possibly due to the presence of thin or haze clouds. The global dust storm occurrence only modulates the correlation behavior during the high-dust period, and the influence is seen above ∼40 km altitude that indicates an enhanced vertical advection sustained till late northern winter. Based on analysis of observational data and simulations with the MarsWRF model, it is found that the difference in correlation behavior between low and high-dust seasons could be explained from the variations in the planetary boundary layer height. Moreover, the dust and water ice interaction pattern has a prominent seasonal variation that is influenced by the water ice cycle, dust cycle, or the dust-ice microphysical relationship. It also has an altitudinal dependency, which changes between low-dust, high-dust, or global dust storm scenarios. |
| Title: | Thermal Forcing of the Nocturnal Near Surface Environment by Martian Water Ice Clouds |
|---|---|
| Authors: | Cooper, B.; de la Torre Juárez, M.; Mischna, M.; Lemmon, M.; Martínez, G.; Kass, D.; Vasavada, A. R.; Campbell, C.; Moores, J. |
| Affiliation: | AA(York University, Toronto, ON Canada; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA; Now at NOIRLab-Gemini North Observatory, Hilo, HI USA), AB(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AC(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AD(Space Science Institute, College Station, TX USA), AE(Lunar and Planetary Institute, Houston, TX USA), AF(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AG(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AH(York University, Toronto, ON Canada), AI(York University, Toronto, ON Canada) |
| Journal: | Journal of Geophysical Research: Planets, Volume 126, Issue 12, article id. e06737. |
| Publication Date: | Dec 2021 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, Mars atmosphere, Mars Clouds, Mars Science Laboratory, REMS |
| Abstract Copyright: | 2021. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2020JE006737 |
| Bibliographic Code: | 2021JGRE..12606737C |
| Abstract: | We explore the potential role of clouds in moderating the nighttime temperature within Gale crater, as observed by the Rover Environmental Monitoring Station (REMS) instrument suite aboard the Curiosity rover. Just prior to aphelion, the decreasing trend in minimum daily temperature within Gale slows down. We investigate if this is due to increased formation of twilight and nighttime clouds, re-radiating heat and reducing atmospheric and surface cooling. While diurnal analysis of REMS temperatures shows brief atmospheric warmings of 3-5 K post-sunset during the occurrence of these clouds, an absence of similar warmings in the ground temperature measurements make it unlikely that clouds are the primary source. Seasonally, however, clouds that persist overnight could cause a warming of daily minimum surface temperatures in the L<SUB>s</SUB>∼20°-50° season. This period can serve as a baseline and allow the potential effects of clouds to be more clearly discerned in the REMS temperature measurements. For this season, and in the peak of the aphelion cloud belt season, our modeled atmospheric energy budget shows a nocturnal decay signature of downward IR reflected and re-emitted flux consistent with the presence and impact of clouds. The expected approximate exponential decay of this flux post-sunset is damped more heavily in cloudier seasons than less cloudy or dusty seasons, suggesting formation and thickening of ice clouds as atmospheric nighttime temperatures cool. |
| Title: | Constraints on Emission Source Locations of Methane Detected by Mars Science Laboratory |
|---|---|
| Authors: | Viúdez-Moreiras, D.; Richardson, M. I.; Newman, C. E. |
| Affiliation: | AA(Centro de Astrobiología (CSIC-INTA), National Institute for Aerospace Technology (INTA), Madrid, Spain), AB(Aeolis Research, Chandler, AZ USA), AC(Aeolis Research, Chandler, AZ USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 126, Issue 12, article id. e06958. |
| Publication Date: | Dec 2021 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | atmospheric chemistry, methane on Mars, Mars Science Laboratory, Trace Gas Orbiter Exomars |
| Abstract Copyright: | 2021 The Authors. |
| DOI: | https://doi.org/10.1029/2021JE006958 |
| Bibliographic Code: | 2021JGRE..12606958V |
| Abstract: | The Sample Analysis at Mars (SAM) instrument on the Mars Science Laboratory (MSL) Curiosity rover has detected both methane spikes and variable background methane abundance in recent years in Gale Crater, Mars. While methane spikes have been attributed to a hypothetical local or regional source emission, the background measurements acquired during the nighttime were postulated to represent the global methane abundance on Mars. However, recent high-accuracy observations by instruments on the Trace Gas Orbiter (TGO) in several locations around the planet have not detected methane at all, apparently contradicting the SAM measurements. This paper analyzes the constraints that TGO and MSL impose on the hypothetical location of the emission source of methane responsible for the levels detected by SAM. The numerical simulations presented here indicate that not only the spikes but also the background measurements performed by MSL must result from localized emissions, specifically in the northwest interior of Gale Crater. Other simulated emission source locations at a greater distance from MSL, even if still within Gale Crater, are difficult to reconcile with current observations by MSL and TGO. Confirming previous studies, these results therefore point either to an improbable scenario, in which the rover has landed close to one of only a few localized emission sources on Mars, or to a problematic scenario, in which an unknown loss mechanism must be invoked that is able to destroy methane orders of magnitude faster than predicted by standard gas chemistry or to a weighted action between both scenarios. |
| Title: | Effect of dust particle size on the climate of Mars |
|---|---|
| Authors: | Wang, Yemeng; Chow, Kim-Chiu; Xiao, Jing; Wong, Chi-Fong |
| Affiliation: | AA(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau), AB(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau), AC(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau), AD(State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau) |
| Journal: | Planetary and Space Science, Volume 208, article id. 105346. |
| Publication Date: | Nov 2021 |
| Origin: | Elsevier BV |
| Keywords: | Mars, Dust, Particle size, General circulation model |
| Abstract Copyright: | (c) 2021 Elsevier Ltd |
| DOI: | https://doi.org/10.1016/j.pss.2021.105346 |
| Bibliographic Code: | 2021P&SS..20805346W |
| Abstract: | Dust particle size is one important property in evaluating the radiative effect of airborne dust. However, its effect on the climate of Mars is not clearly understood. In the present study, some numerical experiments with the Mars climate model MarsWRF have been performed to investigate this issue. In these simulations, the ratio of two sizes (small and large) of dust particles is changed gradually to investigate the corresponding effects on the distribution of dust mixing ratio, thermal field, and the dynamic field. Based on the results of this study, the following effects on the Martian climate have been identified. (1) The effect of small dust particles is significant in the dust season and mainly in the lower atmosphere. (2) Increasing the ratio of small dust particles may increase the heating rate, temperature, westerly wind, and the meridional wind associated with the Hadley circulation during the dust season, as well as a decrease in the easterly wind over the equatorial region. (3) The effect of increasing the ratio of small dust particles is generally more significant in the second episodic dust period during the dust season. This may be due to the longer time of sedimentation for small dust particles. |
| Title: | Lander and rover histories of dust accumulation on and removal from solar arrays on Mars |
|---|---|
| Authors: | Lorenz, Ralph D.; Martínez, German M.; Spiga, Aymeric; Vicente-Retortillo, Alvaro; Newman, Claire E.; Murdoch, Naomi; Forget, Francois; Millour, Ehouarn; Pierron, Thomas |
| Affiliation: | AA(Space Exploration Sector, Johns Hopkins Applied Physics Laboratory, Laurel, MD, 20723, USA), AB(Lunar and Planetary Institute, Universities Space Research Association, Houston, TX, USA), AC(Laboratoire de Météorologie Dynamique/IPSL, Sorbonne Université, CNRS, Ecole Normale Supérieure, PSL Research University, Ecole Polytechnique, 75005, Paris, France), AD(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AE(Aeolis Research, Chandler, AZ, USA), AF(Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Université de Toulouse, Toulouse, France), AG(Laboratoire de Météorologie Dynamique/IPSL, Sorbonne Université, CNRS, Ecole Normale Supérieure, PSL Research University, Ecole Polytechnique, 75005, Paris, France), AH(Laboratoire de Météorologie Dynamique/IPSL, Sorbonne Université, CNRS, Ecole Normale Supérieure, PSL Research University, Ecole Polytechnique, 75005, Paris, France), AI(Laboratoire de Météorologie Dynamique/IPSL, Sorbonne Université, CNRS, Ecole Normale Supérieure, PSL Research University, Ecole Polytechnique, 75005, Paris, France) |
| Journal: | Planetary and Space Science, Volume 207, article id. 105337. |
| Publication Date: | Nov 2021 |
| Origin: | Elsevier BV |
| Keywords: | Solar power, Dust, Dust devils, Mars, Boundary layer meteorology |
| Abstract Copyright: | (c) 2021 The Authors |
| DOI: | https://doi.org/10.1016/j.pss.2021.105337 |
| Bibliographic Code: | 2021P&SS..20705337L |
| Abstract: | The degradation in electrical output of solar arrays on Mars landers and rovers is reviewed. A loss of 0.2% per Sol is typical, although observed rates of decrease in 'dust factor' vary between 0.05% and 2% per Sol. 0.2%/Sol has been observed throughout the first 800 Sols of the ongoing InSight mission, as well as the shorter Mars Pathfinder and Phoenix missions. This rate was also evident for much of the Spirit and Opportunity missions, but the degradation there was episodically reversed by cleaning events due to dust devils and gusts. The enduring success of those rover missions may have given an impression of the long-term viability of solar power on the Martian surface that is not globally-applicable: the occurrence of cleaning events with an operationally-useful frequency seems contingent upon local meteorological circumstances. The conditions for significant cleaning events have apparently not been realized at the InSight landing site, where, notably, dust devils have not been detected in imaging. Optical obscuration by dust deposition and removal has also been observed by ultraviolet sensors on Curiosity, with a similar (but slightly higher) degradation rate. The observations are compared with global circulation model (GCM) results: these predict a geographically somewhat uniform dust deposition rate, while there is some indication that the locations where cleaning events were more frequent may be associated with weaker background winds and a deeper planetary boundary layer. The conventional Dust Devil Activity metric in GCMs does not effectively predict the different dust histories. |
| Title: | Mars Methane Sources in Northwestern Gale Crater Inferred From Back Trajectory Modeling |
|---|---|
| Authors: | Luo, Y.; Mischna, M. A.; Lin, J. C.; Fasoli, B.; Cai, X.; Yung, Y. L. |
| Affiliation: | AA(Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA USA), AB(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AC(Department of Atmospheric Sciences, University of Utah, Salt Lake City, UT USA), AD(Department of Atmospheric Sciences, University of Utah, Salt Lake City, UT USA), AE(Columbia University, New York, NY USA), AF(Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA USA; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA) |
| Journal: | Earth and Space Science, Volume 8, Issue 11, article id. e01915. |
| Publication Date: | Nov 2021 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, methane, back trajectory, MSL, TLS, TGO |
| Abstract Copyright: | 2021 The Authors. Earth and Space Science published by Wiley Periodicals LLC on behalf of American Geophysical Union. |
| DOI: | https://doi.org/10.1029/2021EA001915 |
| Bibliographic Code: | 2021E&SS....801915L |
| Abstract: | During its first seven years of operation, the Sample Analysis at Mars Tunable Laser Spectrometer (TLS) on board the Curiosity rover has detected seven methane spikes above a low background abundance in Gale crater. The methane spikes are likely sourced by surface emission within or around Gale crater. Here, we use inverse Lagrangian modeling techniques to identify upstream emission regions on the Martian surface for these methane spikes at an unprecedented spatial resolution. Inside Gale crater, the northwestern crater floor casts the strongest influence on the detections. Outside Gale crater, the upstream regions common to all the methane spikes extend toward the north. The contrasting results from two consecutive TLS methane measurements performed on the same sol point to an active emission site to the west or the southwest of the Curiosity rover on the northwestern crater floor. The observed spike magnitude and frequency also favor emission sites on the northwestern crater floor, unless there are fast methane removal mechanisms at work, or either the methane spikes of TLS or the non-detections of ExoMars Trace Gas Orbiter cannot be trusted. |
| Title: | Interannual, Seasonal and Regional Variations in the Martian Convective Boundary Layer Derived From GCM Simulations With a Semi-Interactive Dust Transport Model |
|---|---|
| Authors: | Senel, Cem Berk; Temel, Orkun; Lee, Christopher; Newman, Claire E.; Mischna, Michael A.; Muñoz-Esparza, Domingo; Sert, Hakan; Karatekin, Özgür |
| Affiliation: | AA(Royal Observatory of Belgium, Reference Systems and Planetology, Brussels, Belgium), AB(Royal Observatory of Belgium, Reference Systems and Planetology, Brussels, Belgium; KU Leuven, Institute of Astronomy, Leuven, Belgium), AC(Department of Physics, University of Toronto, Toronto, ON Canada; Aeolis Research, Pasadena, CA USA), AD(Aeolis Research, Pasadena, CA USA), AE(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AF(National Center for Atmospheric Research, Boulder, CO USA), AG(Royal Observatory of Belgium, Reference Systems and Planetology, Brussels, Belgium), AH(Royal Observatory of Belgium, Reference Systems and Planetology, Brussels, Belgium) |
| Journal: | Journal of Geophysical Research: Planets, Volume 126, Issue 10, article id. e06965. |
| Publication Date: | Oct 2021 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | dust transport, global circulation modeling, Martian convective boundary layer, turbulence |
| Abstract Copyright: | 2021. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2021JE006965 |
| Bibliographic Code: | 2021JGRE..12606965S |
| Abstract: | We present interannual, seasonal, and regional variations in the daytime Martian convective boundary layer (CBL). Martian CBL meteorology is driven both by the effect of diurnal and seasonal cycles as well as complex Martian topography. One of the most important components of the Martian atmosphere is its dust cycle. Here, we develop a novel semi-interactive dust transport model within the MarsWRF framework, in which the dust is lifted, advected by model winds, mixed, and allowed to sediment, but is then scaled to match two-dimensional maps of the observed daily column-integrated dust opacity. This allows the vertical dust distribution and associated dust radiative heating to be controlled by model processes, while the horizontal dust distribution is constrained to follow observations. We report the impact of the dust cycle on Martian boundary layer meteorology. Enhanced dust transport lowers the global net surface heating rates, decreasing the turbulent mixing in CBL to virtually zero (within the dust storm season) and, enhances the wind shear on average by almost 50%. As a superposition of both impacts, during global dust storms (GDS) in Mars Year (MY) 25 and 34, we find that long-lasting extremely shallow daytime boundary layers can globally form as shallow as 0.5 km (but not for the less intense GDS in MY 28), unlike the 9 km deep and highly turbulent CBL formation at GDS onset and decay. Based on our GCM results, strong CBL suppression lasts as long as approximately 67 and 57 sols during GDS events in MY 25 and 34. |
| Title: | Strong Seasonal and Regional Variations in the Evaporation Rate of Liquid Water on Mars |
|---|---|
| Authors: | Temel, Orkun; Karatekin, Özgür; Mischna, Michael A.; Senel, Cem Berk; Martínez, Germán.; Gloesener, Elodie; Van Hoolst, Tim |
| Affiliation: | AA(KU Leuven, Institute of Astronomy, Leuven, Belgium; Royal Observatory of Belgium, Brussels, Belgium), AB(Royal Observatory of Belgium, Brussels, Belgium), AC(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AD(Royal Observatory of Belgium, Brussels, Belgium), AE(Lunar and Planetary Institute, Houston, TX USA), AF(Royal Observatory of Belgium, Brussels, Belgium; Earth and Life Institute, Université Catholique de Louvain, Louvain-la-Neuve, Belgium), AG(KU Leuven, Institute of Astronomy, Leuven, Belgium; Royal Observatory of Belgium, Brussels, Belgium) |
| Journal: | Journal of Geophysical Research: Planets, Volume 126, Issue 10, article id. e06867. |
| Publication Date: | Oct 2021 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, water, brines, GCM |
| Abstract Copyright: | 2021. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2021JE006867 |
| Bibliographic Code: | 2021JGRE..12606867T |
| Abstract: | We have investigated the seasonal and regional variations in the evaporation rate of both pure liquid water and liquid brine solutions on the surface of Mars. Our evaporation rate estimates are performed using a novel parameterization method taking into account the effects of concentration difference, between the evaporating liquid water solution and the atmosphere, in addition to the effects of near-surface winds. The method is based on atmospheric surface-layer calculations obtained from a global circulation model. We show that near-surface winds strongly enhance strong seasonal variability in the evaporation rate of liquid solutions on Mars. The evaporation rate of a liquid brine solution can vary seasonally up to a factor of 3 and changes by two orders of magnitude depending on the surface elevation and properties of the terrain. |
| Title: | Large Eddy Simulations of the Dusty Martian Convective Boundary Layer With MarsWRF |
|---|---|
| Authors: | Wu, Zhaopeng; Richardson, Mark I.; Zhang, Xi; Cui, Jun; Heavens, Nicholas G.; Lee, Christopher; Li, Tao; Lian, Yuan; Newman, Claire E.; Soto, Alejandro; Temel, Orkun; Toigo, Anthony D.; Witek, Marcin |
| Affiliation: | AA(School of Atmospheric Sciences, Planetary Environmental and Astrobiological Research Laboratory, Sun Yat-Sen University, Zhuhai, China; CAS Center for Excellence in Comparative Planetology, Hefei, China), AB(Aeolis Research, Chandler, AZ USA), AC(Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA USA), AD(School of Atmospheric Sciences, Planetary Environmental and Astrobiological Research Laboratory, Sun Yat-Sen University, Zhuhai, China; CAS Center for Excellence in Comparative Planetology, Hefei, China; CAS Key Laboratory of Lunar and Deep Space Exploration, Chinese Academy of Sciences, National Astronomical Observatories, Beijing, China), AE(Space Science Institute, Boulder, CO USA; Department of Earth Science and Engineering, Imperial College, London, UK), AF(Aeolis Research, Chandler, AZ USA; Department of Physics, University of Toronto, Toronto, ON Canada), AG(CAS Center for Excellence in Comparative Planetology, Hefei, China; CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China), AH(Aeolis Research, Chandler, AZ USA), AI(Aeolis Research, Chandler, AZ USA), AJ(Southwest Research Institute, Boulder, CO USA), AK(KU Leuven, Institute of Astronomy, Leuven, Belgium; Royal Observatory of Belgium, Brussels, Belgium), AL(Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA), AM(Jet Propulsion Laboratory, Pasadena, CA USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 126, Issue 9, article id. e06752. |
| Publication Date: | Sep 2021 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Martian atmosphere, large eddy simulation, convective boundary layer, dust inhomogeneity, radiative-dynamical feedback |
| Abstract Copyright: | 2021. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2020JE006752 |
| Bibliographic Code: | 2021JGRE..12606752W |
| Abstract: | Large eddy simulation (LES) of the Martian convective boundary layer (CBL) with a Mars-adapted version of the Weather Research and Forecasting model is used to examine the impact of aerosol dust radiative-dynamical feedbacks on turbulent mixing. The LES is validated against spacecraft observations and prior modeling. To study dust redistribution by coherent dynamical structures within the CBL, two radiatively active dust distribution scenarios are used: one in which the dust distribution remains fixed and another in which dust is freely transported by CBL motions. In the fixed dust scenario, increasing atmospheric dust loading shades the surface from sunlight and weakens convection. However, a competing effect emerges in the free dust scenario, resulting from the lateral concentration of dust in updrafts. The resulting enhancement of dust radiative heating in upwelling plumes both generates horizontal thermal contrasts in the CBL and increases buoyancy production, jointly enhancing CBL convection. We define a dust inhomogeneity index (DII) to quantify how much dust is concentrated in upwelling plumes. If the DII is large enough, the destabilizing effect of lateral heating contrasts can exceed the stabilizing effect of surface shading such that the CBL depth increases with increasing dust optical depth. Thus, under certain combinations of total dust optical depth and the lateral inhomogeneity of dust, a positive feedback exists between dust optical depth, the vigor and depth of CBL mixing, and—to the extent that dust lifting is controlled by the depth and vigor of CBL mixing—the further lifting of dust from the surface. |
| Title: | The Surface Energy Budget at Gale Crater During the First 2500 Sols of the Mars Science Laboratory Mission |
|---|---|
| Authors: | Martínez, G. M.; Vicente-Retortillo, A.; Vasavada, A. R.; Newman, C. E.; Fischer, E.; Rennó, N. O.; Savijärvi, H.; de la Torre, M.; Ordóñez-Etxeberria, I.; Lemmon, M. T.; Guzewich, S. D.; McConnochie, T. H.; Sebastián, E.; Hueso, R.; Sánchez-Lavega, A. |
| Affiliation: | AA(Lunar and Planetary Institute, Universities Space Research Association, Houston, TX USA; Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI USA), AB(Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI USA; Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AC(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AD(Aeolis Research, Chandler, AZ USA), AE(Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI USA), AF(Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI USA), AG(Institute for Atmospheric and Earth System Research / Physics, University of Helsinki, Helsinki, Finland; Finnish Meteorological Institute, Helsinki, Finland), AH(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AI(Universidad del País Vasco, Bilbao, Spain; Planetario de Pamplona, Pamplona, Spain), AJ(Space Science Institute, College Station, TX USA), AK(NASA Goddard Spaceflight Center, Greenbelt, MD USA), AL(Department of Astronomy, University of Maryland, College Park, MD USA), AM(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AN(Universidad del País Vasco, Bilbao, Spain), AO(Universidad del País Vasco, Bilbao, Spain) |
| Journal: | Journal of Geophysical Research: Planets, Volume 126, Issue 9, article id. e06804. |
| Publication Date: | Sep 2021 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, Mars Science Laboratory, surface energy budget, thermal Forcing, solar energy, REMS |
| Abstract Copyright: | 2021. The Authors. |
| DOI: | https://doi.org/10.1029/2020JE006804 |
| Bibliographic Code: | 2021JGRE..12606804M |
| Abstract: | We use in situ environmental measurements by the Mars Science Laboratory (MSL) mission to obtain the surface energy budget (SEB) across Curiosity's traverse during the first 2500 sols of the mission. This includes values of the downwelling shortwave solar radiation, the upwelling solar radiation reflected by the surface, the downwelling longwave radiation from the atmosphere, the upwelling longwave radiation emitted by the surface, the sensible heat flux associated with turbulent motions, and the latent heat flux associated with water phase changes. We then analyze their temporal variation on different timescales and relate this to the mechanisms causing these variations. Through its Rover Environmental Monitoring Station, MSL allows for a more accurate determination of the SEB than its predecessors on Mars. Moreover, the unprecedented duration, cadence, and frequency of MSL environmental observations allow for analyses of the SEB from diurnal to interannual timescales. The results presented in this article can be used to evaluate the consistency with predictions from atmospheric numerical models, to validate aerosol radiative properties under a range of dust conditions, to understand the energy available for solar-powered missions, and to enable comparisons with measurements of the SEB by the Perseverance rover at Jezero crater. |
| Title: | Gravity Wave Observations by the Mars Science Laboratory REMS Pressure Sensor and Comparison With Mesoscale Atmospheric Modeling With MarsWRF |
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| Authors: | Guzewich, Scott D.; de la Torre Juárez, Manuel; Newman, Claire E.; Mason, Emily; Smith, Michael D.; Miller, Nina; Khayat, Alain S. J.; Kahanpää, Henrik; Viúdez-Moreiras, Daniel; Richardson, Mark I. |
| Affiliation: | AA(NASA Goddard Space Flight Center, Greenbelt, MD USA), AB(Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA USA), AC(Aeolis Research, Chandler, AZ USA), AD(NASA Goddard Space Flight Center, Greenbelt, MD USA; University of Maryland Baltimore County, Baltimore, MD USA; Center for Research and Exploration in Space Science and Technology, NASA/GSFC, Greenbelt, MD USA), AE(NASA Goddard Space Flight Center, Greenbelt, MD USA), AF(University of Nevada Reno, Reno, NV USA), AG(NASA Goddard Space Flight Center, Greenbelt, MD USA; Center for Research and Exploration in Space Science and Technology, NASA/GSFC, Greenbelt, MD USA; University of Maryland College Park, College Park, MD USA), AH(Aalto University School of Electrical Engineering, Espoo, Finland), AI(Centro de Astrobiología (INTA-CSIC), Torrejón de Ardoz, Spain), AJ(Aeolis Research, Chandler, AZ USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 126, Issue 8, article id. e06907. |
| Publication Date: | Aug 2021 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, curiosity, gravity waves, mesoscale, REMS |
| Abstract Copyright: | 2021. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2021JE006907 |
| Bibliographic Code: | 2021JGRE..12606907G |
| Abstract: | Surface pressure measurements on Mars have revealed a wide variety of atmospheric phenomena. The Mars Science Laboratory Rover Environmental Monitoring Station pressure sensor data set is now the longest duration record of surface pressure on Mars. We use the first 2580 Martian sols, nearly 4 Mars years, of measurements to identify atmospheric pressure waves with periods of tens of minutes to hours using wavelet analysis on residual pressure after the tidal harmonics are removed. We find these waves have a clear diurnal cycle with strongest activity in the early morning and late evening and a seasonal cycle with the strongest waves in the second half of the martian year (L<SUB>s</SUB> = 180-360°). The strongest such waves of the entire mission occurred during the Mars Year 34 global dust storm. Comparable atmospheric waves are identified using atmospheric modeling with the MarsWRF general circulation model in a "nested" high spatial resolution mode. With the support of the modeling, we find these waves best fit the expected properties of inertia-gravity waves with horizontal wavelengths of O(100s) of km. |
| Title: | Vortex-Dominated Aeolian Activity at InSight's Landing Site, Part 1: Multi-Instrument Observations, Analysis, and Implications |
|---|---|
| Authors: | Charalambous, C.; McClean, J. B.; Baker, M.; Pike, W. T.; Golombek, M.; Lemmon, M.; Ansan, V.; Perrin, C.; Spiga, A.; Lorenz, R. D.; Banks, M. E.; Murdoch, N.; Rodriguez, S.; Weitz, C. M.; Grant, J. A.; Warner, N. H.; Garvin, J.; Daubar, I. J.; Hauber, E.; Stott, A. E.; Johnson, C. L.; Mittelholz, A.; Warren, T.; Navarro, S.; Sotomayor, L. M.; Maki, J.; Lucas, A.; Banfield, D.; Newman, C.; Viúdez-Moreiras, D.; Pla-García, J.; Lognonné, P.; Banerdt, W. B. |
| Affiliation: | AA(Department of Electrical and Electronic Engineering, South Kensington Campus, Imperial College London, London, UK), AB(Now at MIT Haystack Observatory, Westford, MA USA), AC(Morton K. Blaustein Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD USA), AD(Department of Electrical and Electronic Engineering, South Kensington Campus, Imperial College London, London, UK), AE(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AF(Space Science Institute, Boulder, CO USA), AG(Laboratoire de Planétologie et Géodynamique, UMR 6112-CNRS, Université de Nantes, Nantes Cedex 3, France), AH(Institut de physique du globe de Paris, CNRS, Université de Paris, Paris, France), AI(Laboratoire de Météorologie Dynamique/Institut Pierre-Simon Laplace, Sorbonne Université, Centre National de la Recherche Scientifique, École Polytechnique, École Normalé Supérieure, Campus Pierre et Marie Curie BC99, Paris, France; Institut Universitaire de France, Paris, France), AJ(Johns Hopkins Applied Physics Laboratory, Laurel, MD USA), AK(NASA Goddard Space Flight Center, Greenbelt, MD USA), AL(Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Toulouse, France), AM(Laboratoire de Planétologie et Géodynamique, UMR 6112-CNRS, Université de Nantes, Nantes Cedex 3, France), AN(Planetary Science Institute, Tucson, AZ USA), AO(Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington, DC USA), AP(Department of Geological Sciences, State University of New York at Geneseo, 1 College Circle, Geneseo, NY USA), AQ(Johns Hopkins Applied Physics Laboratory, Laurel, MD USA), AR(Department of Earth, Environmental, and Planetary Sciences, Brown University, Providence, RI USA), AS(German Aerospace Center, Institute of Planetary Research, Berlin, Germany), AT(Department of Electrical and Electronic Engineering, South Kensington Campus, Imperial College London, London, UK), AU(Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC Canada; Planetary Science Institute, Tucson, AZ USA), AV(Institute of Geophysics, ETH Zürich, Zürich, Switzerland), AW(Department of Physics, University of Oxford, Oxford, UK), AX(Centro de Astrobiologíca (CSIC-INTA), Madrid, Spain), AY(Centro de Astrobiologíca (CSIC-INTA), Madrid, Spain), AZ(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), BA(Institut de physique du globe de Paris, CNRS, Université de Paris, Paris, France), BB(Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY USA), BC(Aeolis Research, Chandler, AZ USA), BD(Centro de Astrobiologíca (CSIC-INTA), Madrid, Spain), BE(Centro de Astrobiologíca (CSIC-INTA), Madrid, Spain), BF(Institut de physique du globe de Paris, CNRS, Université de Paris, Paris, France), BG(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 126, Issue 6, article id. e06757. |
| Publication Date: | Jun 2021 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | aeolian changes at the InSight landing site on Mars, convective vortices as a primary driver of particle motion, dust lifting and saltation, multi-instrument measurements constrain the timing and atmospheric conditions of aeolian changes, passing vortices lifting dust are correlated with magnetic signatures, surface creep, surface tracks |
| Abstract Copyright: | 2021. The Authors. |
| DOI: | https://doi.org/10.1029/2020JE006757 |
| Bibliographic Code: | 2021JGRE..12606757C |
| Abstract: | We report the aeolian changes observed in situ by NASA's InSight lander during the first 400 sols of operations: Granule creep, saltation, dust removal, and the formation of dark surface tracks. Aeolian changes are infrequent and sporadic. However, on sols, when they do occur, they consistently appear between noon to 3 p.m., and are associated with the passage of convective vortices during periods of high vortex activity. Aeolian changes are more frequent at elevated locations, such as the top surfaces of rocks and lander footpads. InSight observed these changes using, for the first time, simultaneous in-situ and orbital imaging and high-frequency meteorological, seismological, and magnetic measurements. Seismometer measurements of ground acceleration constrain the timing and trajectory of convective vortex encounters, linking surface changes to source vortices. Magnetometer measurements show perturbations in magnetic field strength during the passage of convective vortices consistent with charged-particle motion. Detachment of sand-scale particles occurs when high background winds and vortex-induced turbulence provide a peak surface friction wind speed above the classic saltation fluid threshold. However, detachment of dust- and granule-scale particles also occurred when the surface friction wind speed remained below this threshold. This may be explained by local enhancement of the surface roughness and other effects described here and further studied in Part 2 (Baker et al., 2021). The lack of saltation and bright dust-coated surfaces at the InSight landing site implies surface stability and the onset of particle motion may be suppressed by dust "cushioning." This differentiates the InSight landing site from other areas on Mars that exhibit more aeolian activity. |
| Title: | The Mars Environmental Dynamics Analyzer, MEDA. A Suite of Environmental Sensors for the Mars 2020 Mission |
|---|---|
| Authors: | Rodriguez-Manfredi, J. A.; de la Torre Juárez, M.; Alonso, A.; Apéstigue, V.; Arruego, I.; Atienza, T.; Banfield, D.; Boland, J.; Carrera, M. A.; Castañer, L.; Ceballos, J.; Chen-Chen, H.; Cobos, A.; Conrad, P. G.; Cordoba, E.; del Río-Gaztelurrutia, T.; de Vicente-Retortillo, A.; Domínguez-Pumar, M.; Espejo, S.; Fairen, A. G.; Fernández-Palma, A.; Ferrándiz, R.; Ferri, F.; Fischer, E.; García-Manchado, A.; García-Villadangos, M.; Genzer, M.; Giménez, S.; Gómez-Elvira, J.; Gómez, F.; Guzewich, S. D.; Harri, A.-M.; Hernández, C. D.; Hieta, M.; Hueso, R.; Jaakonaho, I.; Jiménez, J. J.; Jiménez, V.; Larman, A.; Leiter, R.; Lepinette, A.; Lemmon, M. T.; López, G.; Madsen, S. N.; Mäkinen, T.; Marín, M.; Martín-Soler, J.; Martínez, G.; Molina, A.; Mora-Sotomayor, L.; Moreno-Álvarez, J. F.; Navarro, S.; Newman, C. E.; Ortega, C.; Parrondo, M. C.; Peinado, V.; Peña, A.; Pérez-Grande, I.; Pérez-Hoyos, S.; Pla-García, J.; Polkko, J.; Postigo, M.; Prieto-Ballesteros, O.; Rafkin, S. C. R.; Ramos, M.; Richardson, M. I.; Romeral, J.; Romero, C.; Runyon, K. D.; Saiz-Lopez, A.; Sánchez-Lavega, A.; Sard, I.; Schofield, J. T.; Sebastian, E.; Smith, M. D.; Sullivan, R. J.; Tamppari, L. K.; Thompson, A. D.; Toledo, D.; Torrero, F.; Torres, J.; Urquí, R.; Velasco, T.; Viúdez-Moreiras, D.; Zurita, S.; MEDA Team |
| Affiliation: | AA(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AB(Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA, USA), AC(CRISA-Airbus, Tres Cantos, Spain), AD(Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain), AE(Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain), AF(Universidad Politécnica de Cataluña, Barcelona, Spain), AG(Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY, USA), AH(Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA, USA), AI(Added-Value-Solutions, Elgoibar, Spain), AJ(Universidad Politécnica de Cataluña, Barcelona, Spain), AK(Instituto de Microelectrónica de Sevilla (US-CSIC), Seville, Spain), AL(Universidad del País Vasco (UPV/EHU), Bilbao, Spain), AM(CRISA-Airbus, Tres Cantos, Spain), AN(Carnegie Institution, Washington, DC, USA), AO(Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA, USA), AP(Universidad del País Vasco (UPV/EHU), Bilbao, Spain), AQ(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AR(Universidad Politécnica de Cataluña, Barcelona, Spain), AS(Instituto de Microelectrónica de Sevilla (US-CSIC), Seville, Spain), AT(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AU(Added-Value-Solutions, Elgoibar, Spain), AV(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AW(Università degli Studi di Padova, Padova, Italy), AX(University of Michigan, Ann Arbor, MI, USA), AY(CRISA-Airbus, Tres Cantos, Spain), AZ(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BA(Finnish Meteorological Institute, Helsinki, Finland), BB(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BC(Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain), BD(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BE(NASA Goddard Space Flight Center, Greenbelt, MD, USA), BF(Finnish Meteorological Institute, Helsinki, Finland), BG(Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA, USA), BH(Finnish Meteorological Institute, Helsinki, Finland), BI(Universidad del País Vasco (UPV/EHU), Bilbao, Spain), BJ(Finnish Meteorological Institute, Helsinki, Finland), BK(Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain), BL(Universidad Politécnica de Cataluña, Barcelona, Spain), BM(Added-Value-Solutions, Elgoibar, Spain), BN(Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA, USA), BO(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BP(Space Science Institute, Boulder, CO, USA), BQ(Universidad Politécnica de Cataluña, Barcelona, Spain), BR(Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA, USA), BS(Finnish Meteorological Institute, Helsinki, Finland), BT(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BU(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BV(Lunar and Planetary Institute, Houston, TX, USA), BW(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BX(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), BY(CRISA-Airbus, Tres Cantos, Spain), BZ(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CA(Aeolis Corporation, Sierra Madre, CA, USA), CB(Added-Value-Solutions, Elgoibar, Spain), CC(Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain), CD(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CE(CRISA-Airbus, Tres Cantos, Spain), CF(Universidad Politécnica de Madrid, Madrid, Spain), CG(Universidad del País Vasco (UPV/EHU), Bilbao, Spain), CH(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CI(Finnish Meteorological Institute, Helsinki, Finland), CJ(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CK(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CL(Southwest Research Institute, Boulder, CO, USA), CM(Universidad de Alcalá, Alcalá de Henares, Spain), CN(Aeolis Corporation, Sierra Madre, CA, USA), CO(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CP(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CQ(John Hopkins APL, Laurel, MD, USA), CR(Dept. of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, CSIC, Madrid, Spain), CS(Universidad del País Vasco (UPV/EHU), Bilbao, Spain), CT(Added-Value-Solutions, Elgoibar, Spain), CU(Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA, USA), CV(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), CW(NASA Goddard Space Flight Center, Greenbelt, MD, USA), CX(Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY, USA), CY(Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA, USA), CZ(Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA, USA), DA(Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain), DB(CRISA-Airbus, Tres Cantos, Spain), DC(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), DD(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), DE(CRISA-Airbus, Tres Cantos, Spain), DF(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), DG(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), DH(Centro de Astrobiología (INTA-CSIC), Madrid, Spain; Carnegie Institution, Washington, DC, USA; Università degli Studi di Padova, Padova, Italy; University of Michigan, Ann Arbor, MI, USA; Finnish Meteorological Institute, Helsinki, Finland; Space Science Institute, Boulder, CO, USA; Lunar and Planetary Institute, Houston, TX, USA; Aeolis Corporation, Sierra Madre, CA, USA; Universidad Politécnica de Madrid, Madrid, Spain; Southwest Research Institute, Boulder, CO, USA; Universidad de Alcalá, Alcalá de Henares, Spain; Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA, USA; John Hopkins APL, Laurel, MD, USA; Dept. of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, CSIC, Madrid, Spain; NASA Goddard Space Flight Center, Greenbelt, MD, USA; CRISA-Airbus, Tres Cantos, Spain; Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain; Universidad Politécnica de Cataluña, Barcelona, Spain; Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY, USA; Added-Value-Solutions, Elgoibar, Spain; Instituto de Microelectrónica de Sevilla (US-CSIC), Seville, Spain; Universidad del País Vasco (UPV/EHU), Bilbao, Spain; Carnegie Institution, Washington, DC, USA; Università degli Studi di Padova, Padova, Italy; University of Michigan, Ann Arbor, MI, USA; Finnish Meteorological Institute, Helsinki, Finland; Space Science Institute, Boulder, CO, USA; Lunar and Planetary Institute, Houston, TX, USA; Aeolis Corporation, Sierra Madre, CA, USA; Universidad Politécnica de Madrid, Madrid, Spain; Southwest Research Institute, Boulder, CO, USA; Universidad de Alcalá, Alcalá de Henares, Spain; Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA, USA; John Hopkins APL, Laurel, MD, USA; Dept. of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, CSIC, Madrid, Spain; CRISA-Airbus, Tres Cantos, Spain; Instituto Nacional de Técnica Aeroespacial (INTA), Madrid, Spain; Universidad Politécnica de Cataluña, Barcelona, Spain; Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY, USA; Added-Value-Solutions, Elgoibar, Spain; Instituto de Microelectrónica de Sevilla (US-CSIC), Seville, Spain; Universidad del País Vasco (UPV/EHU), Bilbao, Spain) |
| Journal: | Space Science Reviews, Volume 217, Issue 3, article id.48. |
| Publication Date: | Apr 2021 |
| Origin: | Springer Science and Business Media LLC |
| Keywords: | MEDA instrument, Mars2020, Perseverance, Instruments, Mars, Atmosphere, Pressure, Wind, Temperature, Surface temperature, Albedo, Dust, Clouds, UV, Thermal infrared, Radiation fluxes |
| DOI: | https://doi.org/10.1007/s11214-021-00816-9 |
| Bibliographic Code: | 2021SSRv..217...48R |
| Abstract: | NASA's Mars 2020 (M2020) rover mission includes a suite of sensors to monitor current environmental conditions near the surface of Mars and to constrain bulk aerosol properties from changes in atmospheric radiation at the surface. The Mars Environmental Dynamics Analyzer (MEDA) consists of a set of meteorological sensors including wind sensor, a barometer, a relative humidity sensor, a set of 5 thermocouples to measure atmospheric temperature at ∼1.5 m and ∼0.5 m above the surface, a set of thermopiles to characterize the thermal IR brightness temperatures of the surface and the lower atmosphere. MEDA adds a radiation and dust sensor to monitor the optical atmospheric properties that can be used to infer bulk aerosol physical properties such as particle size distribution, non-sphericity, and concentration. The MEDA package and its scientific purpose are described in this document as well as how it responded to the calibration tests and how it helps prepare for the human exploration of Mars. A comparison is also presented to previous environmental monitoring payloads landed on Mars on the Viking, Pathfinder, Phoenix, MSL, and InSight spacecraft. |
| Title: | Vortex Dominated Aeolian Activity at InSight's Landing Site, Part 2: Local Meteorology, Transport Dynamics, and Model Analysis |
|---|---|
| Authors: | Baker, M.; Newman, C.; Charalambous, C.; Golombek, M.; Spiga, A.; Banfield, D.; Lemmon, M.; Banks, M.; Lorenz, R.; Garvin, J.; Grant, J.; Lewis, K.; Ansan, V.; Warner, N.; Weitz, C.; Wilson, S.; Rodriguez, S. |
| Affiliation: | AA(Center for Earth & Planetary Studies, National Air & Space Museum, Smithsonian Institution, Washington, DC USA; The Morton K. Blaustein Department of Earth & Planetary Sciences, Johns Hopkins University, Baltimore, MD USA), AB(Aeolis Research, Pasadena, CA USA), AC(Imperial College, London, UK), AD(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AE(Laboratoire de Meteorologie Dynamique, Paris, France), AF(Cornell Center for Astrophysics & Planetary Science, Cornell University, Ithaca, NY USA), AG(Space Science Institute, Boulder, CO USA), AH(NASA Goddard Space Flight Center, Greenbelt, MD USA), AI(Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA), AJ(NASA Goddard Space Flight Center, Greenbelt, MD USA), AK(Center for Earth & Planetary Studies, National Air & Space Museum, Smithsonian Institution, Washington, DC USA), AL(The Morton K. Blaustein Department of Earth & Planetary Sciences, Johns Hopkins University, Baltimore, MD USA), AM(Laboratoire de Planétologie et de Géodynamique de Nantes, Nantes, France), AN(Department of Geological Sciences, SUNY Geneseo, Geneseo, NY USA), AO(Planetary Science Institute, Tucson, AZ USA), AP(Center for Earth & Planetary Studies, National Air & Space Museum, Smithsonian Institution, Washington, DC USA), AQ(Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France) |
| Journal: | Journal of Geophysical Research: Planets, Volume 126, Issue 4, article id. e06514. |
| Publication Date: | Apr 2021 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | aeolian sediment transport, Mars surface processes, threshold conditions, vortex dynamics |
| Abstract Copyright: | 2020. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2020JE006514 |
| Bibliographic Code: | 2021JGRE..12606514B |
| Abstract: | Geologic and climatic processes on modern day Mars are heavily influenced by aeolian surface activity, yet the relationship between atmospheric conditions and sediment mobilization is not well understood. The Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport (InSight) spacecraft is uniquely able to address this issue, due to its joint imaging and continuous high frequency meteorological capabilities, which allow for direct comparison between surface activity and atmospheric conditions. Since landing in the volcanic plains of Elysium Planitia, InSight's camera's have recorded intermittent, small scale surface changes, including removal of fine material on the lander footpad, linear tracks and localized surface darkening caused by minor dust removal, and surface creep of granules, as presented in Part 1 (Charalambous et al., 2021, this issue). Surface activity is found to correlate well with the timing of abrupt pressure drops (∆P ∼ 1-9 Pa) and transient wind gusts (v ∼ 14-31 m/s) associated with convective vortex passage. Here we identify the major erosive forces acting on surface particles during these events, including the vertical pressure gradient force at the vortex core and the drag force generated by quickly rotating tangential winds. Orbital and ground truth data suggest that aeolian activity at InSight's landing site is sporadic under modern climatic conditions. Ongoing aeolian surface modifcation is driven primarily by turbulent vortices that sporadically lift dust and redistribute coarser sediment (i.e., sand and granules) but do not aid in the development of organized aeolian bedforms. Surface erosion is localized within the path these vortices take across the surface which is controlled by seasonally reversing background circulation patterns. |
| Title: | Characterizing Dust Radiation Feedback and Refining the Horizontal Resolution of the MarsWRF Model Down to 0.5 Degree |
|---|---|
| Authors: | Gebhardt, C.; Abuelgasim, A.; Fonseca, R. M.; Martín-Torres, J.; Zorzano, M.-P. |
| Affiliation: | AA(National Space Science and Technology Center, United Arab Emirates University, Al Ain, UAE), AB(National Space Science and Technology Center, United Arab Emirates University, Al Ain, UAE; Department of Geography and Urban Sustainability, College of Humanities and Social Sciences, United Arab Emirates University, Al Ain, UAE), AC(Khalifa University of Science and Technology, Abu Dhabi, UAE; Group of Atmospheric Science, Luleå University of Technology, Luleå, Sweden), AD(Group of Atmospheric Science, Luleå University of Technology, Luleå, Sweden; School of Geosciences, University of Aberdeen, Aberdeen, UK; Instituto Andaluz de Ciencias de la Tierra, Granada, Spain), AE(School of Geosciences, University of Aberdeen, Aberdeen, UK; Centro de Astrobiología (CSIC INTA), Torrejón de Ardoz, Madrid Spain) |
| Journal: | Journal of Geophysical Research: Planets, Volume 126, Issue 3, article id. e06672. |
| Publication Date: | Mar 2021 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | dust cycle, dust radiation feedback, interactive dust, MarsWRF model, model resolution, prescribed dust |
| Abstract Copyright: | 2021. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2020JE006672 |
| Bibliographic Code: | 2021JGRE..12606672G |
| Abstract: | In this study, three simulations by the Mars Weather Research and Forecasting Model are compared: two 10 Martian year (MY) 2° × 2° simulations with (i) fully radiatively active dust and (ii) a prescribed dust scenario, and a (iii) 1 MY 0.5° × 0.5° simulation with prescribed dust as in (ii). From comparing (i) and (ii), we found that the impact of dust radiation feedback is individually different for any region. The most striking evidence are major dust lifting activities to the south of Chryse Planitia (S CP) seen in (i) but not in (ii). By contrast, dust lifting and deposition on the southern slopes and inside the Hellas Basin are similar in both simulations. The latter, in turn, points toward a similar near surface atmospheric circulation. In (iii), the total global amount of wind stress lifted dust is by a factor of ∼8 higher than in (ii), with S CP being a major lifting region as in (i). Nonetheless, the surface dust lifting by wind stress in (iii) may be also reduced regionally, as seen at the peak of Elysium Mons because of its unique topography. The zonal mean circulation in (i) is generally of a comparable strength to that in (ii), with exceptions in global dust storm years, when it is clearly stronger in (i), in line with a dustier atmosphere. The differences in the zonal mean circulation between (ii) and (iii) are mostly at lower altitudes and may arise because of differences in the representation of the topography. |
| Title: | Large eddy simulations of the Martian convective boundary layer: Towards developing a new planetary boundary layer scheme |
|---|---|
| Authors: | Temel, Orkun; Senel, Cem Berk; Porchetta, Sara; Muñoz-Esparza, Domingo; Mischna, Michael A.; Van Hoolst, Tim; van Beeck, Jeroen; Karatekin, Özgür |
| Affiliation: | AA(KU Leuven, Institute of Astronomy, Leuven, Belgium; Royal Observatory of Belgium, Brussels, Belgium), AB(von Karman Institute for Fluid Dynamics, Rhode-St-Genese, Belgium), AC(von Karman Institute for Fluid Dynamics, Rhode-St-Genese, Belgium), AD(National Center for Atmospheric Research, CO, USA), AE(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA), AF(Royal Observatory of Belgium, Brussels, Belgium; KU Leuven, Institute of Astronomy, Leuven, Belgium), AG(von Karman Institute for Fluid Dynamics, Rhode-St-Genese, Belgium), AH(Royal Observatory of Belgium, Brussels, Belgium) |
| Journal: | Atmospheric Research, Volume 250, article id. 105381. |
| Publication Date: | Mar 2021 |
| Origin: | Elsevier BV |
| Keywords: | Large eddy simulation, Mars, Planetary boundary layer |
| Abstract Copyright: | (c) 2021 Elsevier B.V. |
| DOI: | https://doi.org/10.1016/j.atmosres.2020.105381 |
| Bibliographic Code: | 2021AtmRe.25005381T |
| Abstract: | The grid resolutions typically employed in atmospheric global circulation and mesoscale models are not sufficient to explicitly resolve the turbulence processes within the planetary boundary layer (PBL). turbulent fluxes are, therefore, fully parameterized in those models, based on empirical relationships for the mixing length scale using PBL schemes. However, microscale models use the large-eddy simulation (LES) technique to resolve turbulence processes. Here, we perform LES computations for the daytime Martian planetary boundary layer, ranging from weakly to strong convective conditions, using the Mars implementation of planetWRF, the MarsWRF model. In this study, our main focus is to investigate the turbulence statistics and turbulent spectrum utilizing our LES results. Then, using the computed turbulence kinetic energy and its dissipation rate, a generic formulation for the mixing length scale variation in the Martian convective boundary layer is proposed. This mixing length formulation is used to derive a Mars-specific PBL scheme and its performance is compared to the PBL scheme currently in use by the MarsWRF model, the MRF scheme. The proposed scheme is tested both in global and mesoscale simulations, which are used to evaluate the convective boundary layer height and near-surface meteorology conditions at the InSight landing site. The presently proposed PBL scheme results in an improved prediction of convective boundary layer height that agree better with the observational estimations acquired by radio occultations of Mars Express in comparison to the MRF scheme. Also, the prediction of near-surface winds at the InSight landing site is slightly improved. |
| Title: | Characteristic features of water ice clouds over Olympus and Arsia Mons using MOM and MRO observations |
|---|---|
| Authors: | Guha, Bijay Kumar; Panda, Jagabandhu; Arya, A. S. |
| Affiliation: | AA(Department of Earth and Atmospheric Sciences, National Institute of Technology, Rourkela, Odisha, 769008, India), AB(Department of Earth and Atmospheric Sciences, National Institute of Technology, Rourkela, Odisha, 769008, India), AC(Space Applications Centre, Indian Space Research Organization, Jodhpur Tekra, Ahmedabad, 380015, India) |
| Journal: | Planetary and Space Science, Volume 196, article id. 105155. |
| Publication Date: | Feb 2021 |
| Origin: | Elsevier BV |
| Keywords: | Mars atmosphere, Olympus mons, Arsia mons, Clouds |
| Abstract Copyright: | (c) 2021 Elsevier Ltd |
| DOI: | https://doi.org/10.1016/j.pss.2020.105155 |
| Bibliographic Code: | 2021P&SS..19605155G |
| Abstract: | The present study used the observations from Mars Color Camera (MCC) onboard Mars Orbiter Mission, from the two instruments onboard Mars Reconnaissance Orbiter, i.e., Mars Climate Sounder (MCS) and Mars Color Imager (MARCI), for investigating the water ice cloud appearance over two Martian volcanos, Olympus Mons and Arsia Mons. Indeed, these regions offer an opportunity to explore the dynamical effects related to the orographic clouds and give an idea about their interactions with atmospheric transport. Also, the long-term MCS profile observations are much useful to emphasize the sub-seasonal, seasonal, and interannual variability of clouds at different altitudes. The MCC and MARCI images show a cloud patch over Olympus Mons within the aphelion and a thin cloud trails over Arsia Mons within the perihelion of Mars years. Night-time MCS observations suggest an appearance of thick low altitude clouds within 15-32 km height during L<SUB>S</SUB> = 35-150° and thin high-altitude clouds within 30-50 km height during L<SUB>S</SUB> = 225-315°. The profile observations over both the volcanic regions show that the atmospheric temperature variations more strongly control the water ice cloud distribution at lower altitudes during northern hemispheric spring and summer. In contrast, the high altitude thin clouds during southern hemispheric spring and summer are found to be more associated with the elevated dustiness and vertical advection of dust-laden mountain induced regional circulation, as suggested by MarsWRF simulated wind. The appearance of the consistent thick followed by thin clouds during aphelion and perihelion season shows a nearly constant cloud water content of ~0.2 and ~0.05 pr μm. The high or low magnitude of cloud water content could be distinguished from the peak water ice extinction within the column, as observed in the inter-annual variations. However, irrespective of low cloud water content during the second half of the year, the presence of high altitude thin clouds leads to an overall cloud vertical depth (≥30 km) higher (mostly visible during the night) than the first half of the year. Comparison of the nighttime appearance of thick clouds (centered at ~20 km) during the first half and thin clouds (centered at ~40 km) during the second half of the year over two volcanos indicates the suitable atmospheric conditions in the case of the Olympus Mons for the former type clouds and over Arsia Mons for the later. Also, the appearance of thick clouds mostly resembles the consistent and stable aphelion cloud cycle. In contrast, the thin high altitude clouds are more variable and influenced by the vertical advection during the perihelion season. Besides, these high altitude clouds drive the more prominent east-west asymmetry in the cloud abundance over the Arsia Mons region during the perihelion period. |
| Title: | Multi-model Meteorological and Aeolian Predictions for Mars 2020 and the Jezero Crater Region |
|---|---|
| Authors: | Newman, C. E.; de la Torre Juárez, M.; Pla-García, J.; Wilson, R. J.; Lewis, S. R.; Neary, L.; Kahre, M. A.; Forget, F.; Spiga, A.; Richardson, M. I.; Daerden, F.; Bertrand, T.; Viúdez-Moreiras, D.; Sullivan, R.; Sánchez-Lavega, A.; Chide, B.; Rodriguez-Manfredi, J. A. |
| Affiliation: | AA(Aeolis Research, Tucson, AZ, USA), AB(Jet Propulsion Laboratory, California Institute of Technology, 91001, Pasadena, CA, USA), AC(Centro de Astrobiología (CSIC-INTA), 28850, Madrid, Spain; Space Science Institute, 80301, Boulder, CO, USA; Space Science Institute, 80301, Boulder, CO, USA), AD(Ames Research Center, Mountain View, CA, USA), AE(The Open University, Milton Keynes, UK), AF(Belgian Institute for Space Aeronomy, Brussels, Belgium), AG(Ames Research Center, Mountain View, CA, USA), AH(Laboratoire de Météorologie Dynamique/Institut Pierre Simon Laplace (LMD/IPSL), Sorbonne Université, Centre National de la Recherche Scientifique (CNRS), École Polytechnique, École Normale Supérieure (ENS), 75005, Paris, France), AI(Laboratoire de Météorologie Dynamique/Institut Pierre Simon Laplace (LMD/IPSL), Sorbonne Université, Centre National de la Recherche Scientifique (CNRS), École Polytechnique, École Normale Supérieure (ENS), 75005, Paris, France; Institut Universitaire de France, 75005, Paris, France; Institut Universitaire de France, 75005, Paris, France), AJ(Aeolis Research, Tucson, AZ, USA), AK(Belgian Institute for Space Aeronomy, Brussels, Belgium), AL(LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris, 92195, Meudon, France; Ames Research Center, Mountain View, CA, USA; Ames Research Center, Mountain View, CA, USA), AM(Centro de Astrobiología (CSIC-INTA), 28850, Madrid, Spain), AN(Cornell Center for Astrophysics and Planetary Science, Cornell University, 14853, Ithaca, NY, USA), AO(Universidad del País Vasco (UPV/EHU), Bilbao, Spain), AP(Institut Supérieur de l'Aéronautique et de l'Espace (ISAE), Toulouse, France), AQ(Centro de Astrobiología (CSIC-INTA), 28850, Madrid, Spain) |
| Journal: | Space Science Reviews, Volume 217, Issue 1, article id.20. |
| Publication Date: | Feb 2021 |
| Origin: | Springer Science and Business Media LLC |
| Keywords: | Mars, Meteorology, Aeolian, Atmosphere, Dust devils, Mars 2020, Jezero crater |
| DOI: | https://doi.org/10.1007/s11214-020-00788-2 |
| Bibliographic Code: | 2021SSRv..217...20N |
| Abstract: | Nine simulations are used to predict the meteorology and aeolian activity of the Mars 2020 landing site region. Predicted seasonal variations of pressure and surface and atmospheric temperature generally agree. Minimum and maximum pressure is predicted at Ls∼145<SUP>∘</SUP> and 250<SUP>∘</SUP>, respectively. Maximum and minimum surface and atmospheric temperature are predicted at Ls∼180<SUP>∘</SUP> and 270<SUP>∘</SUP>, respectively; i.e., are warmest at northern fall equinox not summer solstice. Daily pressure cycles vary more between simulations, possibly due to differences in atmospheric dust distributions. Jezero crater sits inside and close to the NW rim of the huge Isidis basin, whose daytime upslope (∼east-southeasterly) and nighttime downslope (∼northwesterly) winds are predicted to dominate except around summer solstice, when the global circulation produces more southerly wind directions. Wind predictions vary hugely, with annual maximum speeds varying from 11 to 19 ms-<SUP>1</SUP> and daily mean wind speeds peaking in the first half of summer for most simulations but in the second half of the year for two. Most simulations predict net annual sand transport toward the WNW, which is generally consistent with aeolian observations, and peak sand fluxes in the first half of summer, with the weakest fluxes around winter solstice due to opposition between the global circulation and daytime upslope winds. However, one simulation predicts transport toward the NW, while another predicts fluxes peaking later and transport toward the WSW. Vortex activity is predicted to peak in summer and dip around winter solstice, and to be greater than at InSight and much greater than in Gale crater. |
| Title: | Meteorological Predictions for Mars 2020 Perseverance Rover Landing Site at Jezero Crater |
|---|---|
| Authors: | Pla-García, Jorge; Rafkin, S. C. R.; Martinez, G. M.; Vicente-Retortillo, Á.; Newman, C. E.; Savijärvi, H.; de la Torre, M.; Rodriguez-Manfredi, J. A.; Gómez, F.; Molina, A.; Viúdez-Moreiras, D.; Harri, Ari-Matti |
| Affiliation: | AA(Centro de Astrobiología (CSIC-INTA), Madrid, Spain; Space Science Institute, Boulder, CO, USA; Space Science Institute, Boulder, CO, USA), AB(Southwest Research Institute, Boulder, CO, USA), AC(Lunar and Planetary Institute, Houston, TX, USA; University of Michigan, Ann Arbor, MI, USA; University of Michigan, Ann Arbor, MI, USA), AD(Centro de Astrobiología (CSIC-INTA), Madrid, Spain; University of Michigan, Ann Arbor, MI, USA; University of Michigan, Ann Arbor, MI, USA), AE(Aeolis Research, Chandler, AZ, USA), AF(Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, Finland; Finnish Meteorological Institute, Helsinki, Finland; Finnish Meteorological Institute, Helsinki, Finland), AG(Jet Propulsion Laboratory/CalTech, Pasadena, CA, USA), AH(Centro de Astrobiología (CSIC-INTA), Madrid, Spain), AI(Centro de Astrobiología (CSIC-INTA), Madrid, Spain), AJ(Centro de Astrobiología (CSIC-INTA), Madrid, Spain), AK(Centro de Astrobiología (CSIC-INTA), Madrid, Spain), AL(Finnish Meteorological Institute, Helsinki, Finland) |
| Journal: | Space Science Reviews, Volume 216, Issue 8, article id.148. |
| Publication Date: | Dec 2020 |
| Origin: | Springer Science and Business Media LLC |
| Keywords: | Mars, Atmosphere, Mars 2020, Perseverance |
| DOI: | https://doi.org/10.1007/s11214-020-00763-x |
| Bibliographic Code: | 2020SSRv..216..148P |
| Abstract: | The Mars Regional Atmospheric Modeling System (MRAMS) and a nested simulation of the Mars Weather Research and Forecasting model (MarsWRF) are used to predict the local meteorological conditions at the Mars 2020 Perseverance rover landing site inside Jezero crater (Mars). These predictions are complemented with the COmplutense and MIchigan MArs Radiative Transfer model (COMIMART) and with the local Single Column Model (SCM) to further refine predictions of radiative forcing and the water cycle respectively. The primary objective is to facilitate interpretation of the meteorological measurements to be obtained by the Mars Environmental Dynamics Analyzer (MEDA) aboard the rover, but also to provide predictions of the meteorological phenomena and seasonal changes that might impact operations, from both a risk perspective and from the perspective of being better prepared to make certain measurements. A full diurnal cycle at four different seasons (L<SUB>s</SUB> 0<SUP>∘</SUP>, 90<SUP>∘</SUP>, 180<SUP>∘</SUP>, and 270<SUP>∘</SUP>) is investigated. Air and ground temperatures, pressure, wind speed and direction, surface radiative fluxes and moisture data are modeled. The good agreement between observations and modeling in prior works [Pla-Garcia et al. in Icarus 280:103-113, 2016; Newman et al. in Icarus 291:203-231, 2017; Vicente-Retortillo et al. in Sci. Rep. 8(1):1-8, 2018; Savijärvi et al. in Icarus, 2020] provides confidence in utilizing these models results to predict the meteorological environment at Mars 2020 Perseverance rover landing site inside Jezero crater. The data returned by MEDA will determine the extent to which this confidence was justified. |
| Title: | Atmospheric transport into polar regions on Mars in different orbital epochs |
|---|---|
| Authors: | Toigo, Anthony D.; Waugh, Darryn W.; Guzewich, Scott D. |
| Affiliation: | AA(Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA), AB(Department of Earth and Planetary Science, Johns Hopkins University, Baltimore, MD, USA), AC(NASA Goddard Space Flight Center, Greenbelt, MD, USA) |
| Journal: | Icarus, Volume 347, article id. 113816. |
| Publication Date: | Sep 2020 |
| Origin: | Elsevier BV |
| Keywords: | Mars, atmosphere, Mars, polar caps, Mars, climate, Atmosphere, dynamics |
| Abstract Copyright: | (c) 2020 Elsevier Inc. |
| DOI: | https://doi.org/10.1016/j.icarus.2020.113816 |
| Bibliographic Code: | 2020Icar..34713816T |
| Abstract: | The variation of the transport of air into Martian polar regions with obliquity is examined using a series of MarsWRF general circulation model simulations which include idealized age of air and exponential decay tracers. These show substantial changes in the circulation, polar vortex structure, and tracer transport with changes in obliquity. These changes are non-monotonic with respect to obliquity, as well as differing between the summer and winter polar regions. In particular, there is an increase in the rate of vertically-integrated transport of air to the winter pole as obliquity increases from 5° to 25° followed by a decrease from 25° to 55°, with generally the reverse trends for transport to the summer pole. This behavior suggests that the amount of dust transport into polar regions will vary with obliquity, and could contribute to the apparent cyclical deposition of dust in polar regions as expressed in the polar layered deposits. Furthermore, the non-monotonic variation with obliquity suggests that visible changes in the appearance of polar layering may vary on a cycle with half the period of the cycle over the full obliquity variation range. |
| Title: | Fully Interactive and Refined Resolution Simulations of the Martian Dust Cycle by the MarsWRF Model |
|---|---|
| Authors: | Gebhardt, C.; Abuelgasim, A.; Fonseca, R. M.; Martín-Torres, J.; Zorzano, M.-P. |
| Affiliation: | AA(National Space Science and Technology Center, United Arab Emirates University, Al Ain, UAE), AB(Department of Geography and Urban Sustainability, College of Humanities and Social Sciences, United Arab Emirates University, Al Ain, UAE; National Space Science and Technology Center, United Arab Emirates University, Al Ain, UAE), AC(Khalifa University of Science and Technology, Abu Dhabi, UAE; Group of Atmospheric Science, Luleå University of Technology, Luleå, Sweden), AD(School of Geosciences, University of Aberdeen, Aberdeen, UK; Instituto Andaluz de Ciencias de la Tierra, Granada, Spain; Group of Atmospheric Science, Luleå University of Technology, Luleå, Sweden), AE(Centro de Astrobiología (CSIC-INTA), Torrejón de Ardoz, Madrid, Spain; School of Geosciences, University of Aberdeen, Aberdeen, UK) |
| Journal: | Journal of Geophysical Research: Planets, Volume 125, Issue 9, article id. e06253. |
| Publication Date: | Sep 2020 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars atmosphere, Mars climate modelling, dust storms, MarsWRF, Interactive dust, model resolution |
| Abstract Copyright: | ©2020. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2019JE006253 |
| Bibliographic Code: | 2020JGRE..12506253G |
| Abstract: | The MarsWRF model is set up with fully interactive dust at 5° × 5° and 2° × 2 resolution. The latter allows for a better representation of topography and other surface properties. An infinite reservoir of surface dust is assumed for both resolutions. For 5° × 5°, surface dust lifting by wind stress takes place over broad areas, occurring in about 20% of the model's grid cells. For 2° × 2°, it is more spatially restricted, occurring in less than 5% of the grid cells, and somewhat reminiscent of the corridors Acidalia-Chryse, Utopia-Isidis, and Arcadia-West of Tharsis. The onset times of major dust storms—large regional storms or global dust storm events (GDEs)—do not exhibit much interannual variability, typically occurring at around L<SUB>s</SUB> 260°. However, their magnitude does show significant interannual variability—with only small regional storms in some years, large regional storms in others, and some years with GDEs—owing to the interaction between major dust lifting regions at low latitudes. The latter is consistent with observed GDEs having several active dust lifting centers. The agreement between the model's surface dust distribution and observation-based dust cover index maps is potentially better for 2° × 2°. For the latter, there is also significant surface dust lifting by wind stress in the aphelion season that is largely confined to the Hellas basin. It has a recurring time pattern of 2-7 sols, possibly resulting from the interaction between midlatitude baroclinic systems and local downslope flows. |
| Title: | Changes in Soil Cohesion Due to Water Vapor Exchange: A Proposed Dry-Flow Trigger Mechanism for Recurring Slope Lineae on Mars |
|---|---|
| Authors: | Gough, R. V.; Nuding, D. L.; Archer, P. D.; Fernanders, M. S.; Guzewich, S. D.; Tolbert, M. A.; Toigo, A. D. |
| Affiliation: | AA(Cooperative Institute for Research in Environmental Sciences and Department of Chemistry, University of Colorado, Boulder, CO USA), AB(Applied Physics Laboratory, Johns Hopkins University, Laurel, MD USA), AC(Jacobs, NASA Johnson Space Center, Houston, TX USA), AD(Cooperative Institute for Research in Environmental Sciences and Department of Chemistry, University of Colorado, Boulder, CO USA), AE(NASA-Goddard Space Flight Center, Greenbelt, MD USA), AF(Cooperative Institute for Research in Environmental Sciences and Department of Chemistry, University of Colorado, Boulder, CO USA), AG(Applied Physics Laboratory, Johns Hopkins University, Laurel, MD USA) |
| Journal: | Geophysical Research Letters, Volume 47, Issue 11, article id. e87618. |
| Publication Date: | Jun 2020 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, recurring slope lineae, water vapor, salt, perchlorate, humidity |
| Abstract Copyright: | ©2020. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2020GL087618 |
| Bibliographic Code: | 2020GeoRL..4787618G |
| Abstract: | Recurring slope lineae (RSL) are seasonal flows on steep slopes on Mars. Their formation mechanism is unknown, but dry granular flows are a likely explanation. Any proposed trigger for these flows must be consistent with the observed temperature dependence of RSL: more active in warmer months or when sun-facing. Here, we use atmospheric modeling and laboratory experiments to explore a potential mechanism that involves both wet and dry processes at Hale Crater, a known RSL location. We propose that dry flows are triggered by changes in soil cohesion due to the loss of water. When surface temperature and humidity were experimentally simulated, salts likely found in the soil only completely dehydrated during the active season for RSL. We propose that the loss of water from soil in warmer months (or when illuminated) lowers soil cohesion and maximum stability angle. Slope failure may occur, exposing darker underlying material and creating RSL. |
| Title: | The role of atmospheric pressure on Mars surface properties and early Mars climate modeling |
|---|---|
| Authors: | Mischna, Michael A.; Piqueux, Sylvain |
| Affiliation: | AA(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA), AB(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA) |
| Journal: | Icarus, Volume 342, article id. 113496. |
| Publication Date: | May 2020 |
| Origin: | Elsevier BV |
| Keywords: | Mars atmosphere, Mars climate, Mars surface, Atmospheres, Evolution |
| Abstract Copyright: | (c) 2020 Elsevier Inc. |
| DOI: | https://doi.org/10.1016/j.icarus.2019.113496 |
| Bibliographic Code: | 2020Icar..34213496M |
| Abstract: | The thermal inertia of a planetary surface is a compound function of the regolith thermal conductivity, density and specific heat. On planetary bodies with atmospheres, the conductivity of the surface must account for the contributions of both the solid component of the surface as well as that of atmospheric gas found in the interstitial pore spaces. Today, variations in thermal inertia and thermal conductivity on Mars affect the size and timing of areas for which surface temperatures exceed the melting point temperature of water, which is a necessary-but-not-sufficient prerequisite for surface liquid water. Models of past Mars climate, when the atmosphere may have been significantly thicker than at present, have largely neglected the potential role of interstitial atmospheric gas as a thermally conducting element of the 'surface,' though we show here that such underestimation of surface conductivity and thermal inertia has no appreciable effect on models of past Mars climate. In more recent Mars history, changes in obliquity have a similar effect of inflating or collapsing the Mars atmosphere, though to a lesser extent. Orbital changes will also modify surface thermal properties, leading to variations in surface conductivity (and thermal inertia) on 10<SUP>5</SUP>-10<SUP>7</SUP> year cycles. We show that these variations, in fact, should not be neglected. We propose an obliquity-driven cycle of surface evolution that drives variability in surface thermal inertia, and suggest that the potential for liquid water at the surface should increase with time following large, positive excursions in Mars' obliquity. |
| Title: | Methane release on Early Mars by atmospheric collapse and atmospheric reinflation |
|---|---|
| Authors: | Kite, Edwin S.; Mischna, Michael A.; Gao, Peter; Yung, Yuk L.; Turbet, Martin |
| Affiliation: | AA(University of Chicago, Chicago, IL, 6063, USA), AB(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109, USA), AC(NASA Ames Research Center, Mountain View, CA, 94035, USA; University of California, Berkeley, CA, 94720, USA), AD(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109, USA; California Institute of Technology, Pasadena, CA, 91125, USA), AE(Laboratoire de Météorologie Dynamique, IPSL, Sorbonne Universités, UPMC Univ Paris 06, CNRS, Paris, 75005, France; Observatoire Astronomique de l'Université de Genève, 51 Chemin des Maillettes, 1290, Sauverny, Switzerland) |
| Journal: | Planetary and Space Science, Volume 181, article id. 104820. |
| Publication Date: | Feb 2020 |
| Origin: | Elsevier BV |
| Abstract Copyright: | (c) 2020 Elsevier Ltd |
| DOI: | https://doi.org/10.1016/j.pss.2019.104820 |
| Bibliographic Code: | 2020P&SS..18104820K |
| Abstract: | A candidate explanation for Early Mars rivers is atmospheric warming due to surface release of H<SUB>2</SUB> or CH<SUB>4</SUB> gas. However, it remains unknown how much gas could be released in a single event. We model the CH<SUB>4</SUB> release by one mechanism for rapid release of CH<SUB>4</SUB> from clathrate. By modeling how CH<SUB>4</SUB>-clathrate release is affected by changes in Mars' obliquity and atmospheric composition, we find that a large fraction of total outgassing from CH<SUB>4</SUB> clathrate occurs following Mars' first prolonged atmospheric collapse. This atmosphere-collapse-initiated CH<SUB>4</SUB>-release mechanism has three stages. (1) Rapid collapse of Early Mars' carbon dioxide atmosphere initiates a slower shift of water ice from high ground to the poles. (2) Upon subsequent CO<SUB>2</SUB>-atmosphere re-inflation and CO<SUB>2</SUB>-greenhouse warming, low-latitude clathrate decomposes and releases methane gas. (3) Methane can then perturb atmospheric chemistry and surface temperature, until photochemical processes destroy the methane. <P />Within our model, we find that under some circumstances a Titan-like haze layer would be expected to form, consistent with transient deposition of abundant complex abiotic organic matter on the Early Mars surface. We also find that this CH<SUB>4</SUB>-release mechanism can warm Early Mars, but special circumstances are required in order to uncork 10<SUP>17</SUP> kg of CH<SUB>4</SUB>, the minimum needed for strong warming. Specifically, strong warming only occurs when the fraction of the hydrate stability zone that is initially occupied by clathrate exceeds 10%, and when Mars' first prolonged atmospheric collapse occurs for atmospheric pressure >1 bar. |
| Title: | MarsWRF Convective Vortex and Dust Devil Predictions for Gale Crater Over 3 Mars Years and Comparison With MSL-REMS Observations |
|---|---|
| Authors: | Newman, C. E.; Kahanpää, H.; Richardson, M. I.; Martínez, G. M.; Vicente-Retortillo, A.; Lemmon, M. T. |
| Affiliation: | AA(Aeolis Research, Pasadena, CA USA), AB(School of Electrical Engineering, Aalto University, Espoo, Finland), AC(Aeolis Research, Pasadena, CA USA), AD(Lunar and Planetary Institute, Universities Space Research Association, Houston, TX USA; College of Engineering, University of Michigan, Ann Arbor, MI USA), AE(College of Engineering, University of Michigan, Ann Arbor, MI USA), AF(Space Science Institute, College Station, TX USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 124, Issue 12, pp. 3442-3468. |
| Publication Date: | Dec 2019 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, Convective vortices, Dust devils, Gale Crater, Mars Science Laboratory, Mars atmospheric modeling |
| Abstract Copyright: | ©2019. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2019JE006082 |
| Bibliographic Code: | 2019JGRE..124.3442N |
| Abstract: | Convective vortices and dust devils have been inferred and observed in Gale Crater, Mars, using Mars Science Laboratory (MSL) meteorological data and camera images. Rennó et al. (1998, <A href="https://doi.org/10.1175/1520-0469(1998)055<3244:asttfd>2.0.co2">https://doi.org/10.1175/1520-0469(1998)055<3244:asttfd>2.0.co2</A>) modeled convective vortices as convective heat engines and predicted a "dust devil activity" (DDA) that depends only on local meteorological variables, specifically the sensible heat flux and the vertical thermodynamic efficiency which increases with the pressure thickness of the planetary boundary layer. This work uses output from the MarsWRF General Circulation Model, run with high-resolution nests over Gale Crater, to predict DDA as a function of location, time of day, and season, and compares these predictions to the record of vortices found in MSL's Rover Environmental Monitoring Station pressure data set. Much of the observed time-of-day and seasonal variation of vortex activity is captured, such as maximum (minimum) activity in southern summer (winter), peaking between 11:00 and 14:00. However, while two daily peaks are predicted around both equinoxes, only a late morning peak is observed. An increase in vortex activity is predicted as MSL climbs the northwest slopes of Aeolis Mons, as observed. This is attributed largely to increased sensible heat flux, due to (i) larger daytime surface-to-air temperature differences over higher terrain, enhanced by reduced thermal inertia, and (ii) the increase in drag velocity associated with faster daytime upslope winds. However, the observed increase in number of vortex pressure drops is much stronger than the predicted DDA increase, although a better match exists when a threshold DDA is used. |
| Title: | Vertical and horizontal heterogeneity of atmospheric dust loading in northern Gale Crater, Mars |
|---|---|
| Authors: | Moore, Casey A.; Moores, John E.; Newman, Claire E.; Lemmon, Mark T.; Guzewich, Scott D.; Battalio, Michael |
| Affiliation: | AA(York University, Centre for Research in Earth and Space Sciences (CRESS), 4700 Keele Street, Toronto, ON M3J 1P3, Canada), AB(York University, Centre for Research in Earth and Space Sciences (CRESS), 4700 Keele Street, Toronto, ON M3J 1P3, Canada), AC(Aeolis Research, Pasadena, CA 91107, United States), AD(Texas A&M University, Department of Atmospheric Sciences, MS 3150, College Station, TX 77843, United States), AE(NASA Goddard Space Flight Center, Greenbelt, MD 20771, United States), AF(Texas A&M University, Department of Atmospheric Sciences, MS 3150, College Station, TX 77843, United States) |
| Journal: | Icarus, Volume 329, p. 197-206. |
| Publication Date: | Sep 2019 |
| Origin: | Elsevier BV |
| Keywords: | Mars, Atmospheric dust, Extinction, Opacity, Sedimentation |
| Abstract Copyright: | (c) 2019 Elsevier Inc. |
| DOI: | https://doi.org/10.1016/j.icarus.2019.03.041 |
| Bibliographic Code: | 2019Icar..329..197M |
| Abstract: | This paper updates the record of atmospheric dust loading within northern Gale Crater, Mars, by providing line-of-sight extinction (LOS-Ext) measurements of the intervening dust between the rover and the crater rim. These measurements are derived from images taken with the Navigation Cameras (Navcam) onboard the Mars Science Laboratory (MSL) rover, Curiosity. The observations span 2.44 Mars years, from Mars Year (MY) 31 at a solar longitude (L<SUB>S</SUB>) of 208° to t L<SUB>S</SUB> = 7° of MY34, sols 100-1701 of the MSL surface mission. This work examines the dataset for seasonal trends of the LOS-Ext in addition to horizontal variations and the vertical structure of LOS-Ext. The LOS-Ext has a repetitive pattern with a single peak in the latter half of the Mars year. The atmosphere in the crater is well mixed horizontally but not vertically as larger LOS-Ext is seen nearer the crater floor than at higher altitudes within the crater. The results allow a discussion on whether or not Gale Crater is a sink for atmospheric dust or a source of atmospheric dust in the current era. |
| Title: | MARSWRF Prediction of Entry Descent Landing Profiles: Applications to Mars Exploration |
|---|---|
| Authors: | Fonseca, Ricardo Morais; Zorzano, María-Paz; Martín-Torres, Javier |
| Affiliation: | AA(Division of Space Technology, Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology, Luleå, Sweden), AB(Centro de Astrobiología (INTA-CSIC), Madrid, Spain; Division of Space Technology, Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology, Luleå, Sweden), AC(Division of Space Technology, Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology, Luleå, Sweden; Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR), Granada, Spain; The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Misasa, Tottori, Japan) |
| Journal: | Earth and Space Science, Volume 6, Issue 8, pp. 1440-1459. |
| Publication Date: | Aug 2019 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, atmosphere, EDL, MarsWRF, ExoMars 2020, Mars 2020 |
| Abstract Copyright: | ©2019. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2019EA000575 |
| Bibliographic Code: | 2019E&SS....6.1440F |
| Abstract: | In this paper we use the Mars implementation of the Planet Weather Research and Forecasting model, MarsWRF, to simulate the Entry, Descent and Landing (EDL) vertical profiles from six past missions: Pathfinder, Mars Exploration Rovers Opportunity and Spirit, Phoenix, Mars Science Laboratory Curiosity rover, and ExoMars 2016 (Schiaparelli), and compare the results with observed data. In order to investigate the sensitivity of the model predictions to the atmospheric dust distribution, MarsWRF is run with two prescribed dust scenarios. It is concluded that the MarsWRF EDL predictions can be used for guidance into the design and planning stage of future missions to the planet, as it generally captures the observed EDL profiles, although it has a tendency to underestimate the temperature and overestimate the density for heights above 15 km. This could be attributed to an incorrect representation of the observed dust loading. We have used the model to predict the EDL conditions that may be encountered by two future missions: ExoMars 2020 and Mars 2020. When run for Oxia Planum and Jezero Crater for the expected landing time, MarsWRF predicts a large sensitivity to the dust loading in particular for the horizontal wind speed above 10-15 km with maximum differences of up to ±30 m/s for the former and ±15 m/s for the latter site. For both sites, the best time for EDL, that is, when the wind speed is generally the weakest with smaller shifts in direction, is predicted to be in the late morning and early afternoon. |
| Title: | The Methane Diurnal Variation and Microseepage Flux at Gale Crater, Mars as Constrained by the ExoMars Trace Gas Orbiter and Curiosity Observations |
|---|---|
| Authors: | Moores, John E.; King, Penelope L.; Smith, Christina L.; Martinez, German M.; Newman, Claire E.; Guzewich, Scott D.; Meslin, Pierre-Yves; Webster, Christopher R.; Mahaffy, Paul R.; Atreya, Sushil K.; Schuerger, Andrew C. |
| Affiliation: | AA(Centre for Research in Earth and Space Science, York University, Toronto, Ontario Canada; Research School of Earth Sciences, Australian National University, Canberra, ACT Australia), AB(Research School of Earth Sciences, Australian National University, Canberra, ACT Australia), AC(Centre for Research in Earth and Space Science, York University, Toronto, Ontario Canada), AD(Lunar and Planetary Institute, Houston, TX USA), AE(Aeolis Research, Pasadena, CA USA), AF(NASA Goddard Space Flight Center, Greenbelt, MD USA), AG(Département de Physique, Université Paul Sabatier, Toulouse, France), AH(NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AI(NASA Goddard Space Flight Center, Greenbelt, MD USA), AJ(Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI USA), AK(Department of Plant Pathology, University of Florida, Gainesville, FL USA) |
| Journal: | Geophysical Research Letters, Volume 46, Issue 16, pp. 9430-9438. |
| Publication Date: | Aug 2019 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, methane, boundary layer, dust, atmosphere |
| Abstract Copyright: | ©2019. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2019GL083800 |
| Bibliographic Code: | 2019GeoRL..46.9430M |
| Abstract: | The upper bound of 50 parts per trillion by volume for Mars methane above 5 km established by the ExoMars Trace Gas Orbiter, substantially lower than the 410 parts per trillion by volume average measured overnight by the Curiosity Rover, places a strong constraint on the daytime methane flux at the Gale crater. We propose that these measurements may be largely reconciled by the inhibition of mixing near the surface overnight, whereby methane emitted from the subsurface accumulates within meters of the surface before being mixed below detection limits at dawn. A model of this scenario allows the first precise calculation of microseepage fluxes at Gale to be derived, consistent with a constant 1.5 × 10<SUP>-10</SUP> kg·m<SUP>-2</SUP>·sol<SUP>-1</SUP> (5.4 × 10<SUP>-5</SUP> tonnes·km<SUP>-2</SUP>·year<SUP>-1</SUP>) source at depth. Under this scenario, only 2.7 × 10<SUP>4</SUP> km<SUP>2</SUP> of Mars's surface may be emitting methane, unless a fast destruction mechanism exists. |
| Title: | Flow Associated With the Condensation and Sublimation of Polar Ice Caps on Mars |
|---|---|
| Authors: | Chow, Kim-Chiu; Xiao, Jing; Chan, Kwing L.; Wong, Chi-Fong |
| Affiliation: | AA(Space Science Institute/Lunar and Planetary Science Laboratory, Macau University of Science and Technology, Taipa Macau), AB(Space Science Institute/Lunar and Planetary Science Laboratory, Macau University of Science and Technology, Taipa Macau), AC(Space Science Institute/Lunar and Planetary Science Laboratory, Macau University of Science and Technology, Taipa Macau), AD(Space Science Institute/Lunar and Planetary Science Laboratory, Macau University of Science and Technology, Taipa Macau) |
| Journal: | Journal of Geophysical Research: Planets, Volume 124, Issue 6, pp. 1570-1580. |
| Publication Date: | Jun 2019 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, ice caps, sublimation flow, condensation flow |
| Abstract Copyright: | ©2019. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2018JE005848 |
| Bibliographic Code: | 2019JGRE..124.1570C |
| Abstract: | The flow associated with the sublimation and condensation of carbon dioxide ice in the polar regions of Mars is an important part of the general circulation. However, so far the pattern of the flow is generally not well known. In this study, a Mars general circulation model (MarsWRF) has been applied to derive the pattern of this flow based on some specially designed experiments. The results suggest that the equatorward sublimation and the poleward condensation flows in both hemispheres are rather shallow except near the poles, and the strength of the sublimation flow is significantly stronger than the condensation flow in both hemispheres. The results also show that the strength of the sublimation and condensation flow in the southern hemisphere is much stronger than that in the northern hemisphere. During the summer time, the surface wind in the high-latitude region near the pole could be dominated by the sublimation flow. |
| Title: | Atmospheric transport of subsurface, sporadic, time-varying methane releases on Mars |
|---|---|
| Authors: | Temel, Orkun; Karatekin, Özgür; Gloesener, Elodie; Mischna, Michael A.; van Beeck, Jeroen |
| Affiliation: | AA(von Karman Institute for Fluid Dynamics, Rhode-St-Genèse, Belgium; Royal Observatory of Belgium, Brussels, Belgium), AB(Royal Observatory of Belgium, Brussels, Belgium), AC(Royal Observatory of Belgium, Brussels, Belgium; Université catholique de Louvain, Louvain-la-Neuve, Belgium), AD(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA), AE(von Karman Institute for Fluid Dynamics, Rhode-St-Genèse, Belgium) |
| Journal: | Icarus, Volume 325, p. 39-54. |
| Publication Date: | Jun 2019 |
| Origin: | Elsevier BV |
| Keywords: | Mars, atmosphere, surface, Atmospheres, dynamics, Meteorology, General circulation modeling |
| Abstract Copyright: | (c) 2019 Elsevier Inc. |
| DOI: | https://doi.org/10.1016/j.icarus.2019.02.014 |
| Bibliographic Code: | 2019Icar..325...39T |
| Abstract: | This study is devoted to the general circulation modeling (GCM) of methane transport in the Martian atmosphere. A localized source originating from a near-subsurface methane reservoir is considered in the GCM simulations, which are performed with a modified version of the Weather Research and Forecasting (WRF) model, MarsWRF. The localized strength of a methane source varies with time, based on a 1-D near-subsurface diffusive transport. Time-varying surface release scenarios are also compared with an instantaneous release scenario. After release from the surface, the methane transport is investigated in the GCM as a passive scalar over time scales varying between 15 and 60 days, much shorter than the photochemical lifetime. Different emission scenarios of various duration and source intensity, as well as multiple locations with different elevation and terrain complexity are considered, to reproduce the substantial concentrations of methane (up to 50 ppb) observed in the northern hemisphere of Mars in 2003 (Mumma et al., 2009). Among the scenarios considered, the observations are reproduced best for an emission scenario of 45 sols duration, during which a total amount of about 90,000 metric tons of methane is released. The results reveal that observed Mars methane plumes in the northern hemisphere of Mars by Mumma et al. (2009) can be reproduced using a localized, time-varying methane source, consistent with a near surface methane reservoir. |
| Title: | Replication of the historic record of Martian global dust storm occurrence in an atmospheric general circulation model |
|---|---|
| Authors: | Shirley, James H.; Newman, Claire E.; Mischna, Michael A.; Richardson, Mark I. |
| Affiliation: | AA(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States), AB(Aeolis Research, Pasadena, CA, United States), AC(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States), AD(Aeolis Research, Pasadena, CA, United States) |
| Journal: | Icarus, Volume 317, p. 197-208. |
| Publication Date: | Jan 2019 |
| Origin: | Elsevier BV |
| Abstract Copyright: | (c) 2019 Elsevier Inc. |
| DOI: | https://doi.org/10.1016/j.icarus.2018.07.024 |
| Bibliographic Code: | 2019Icar..317..197S |
| Abstract: | The MarsWRF Mars general circulation model (GCM) with radiatively active dust and orbit-spin coupling reproduces the observational record of Mars years with and without global dust storms (GDS) with a success rate of 77%. Atmospheric conditions diagnostic to the occurrence or non-occurrence of GDS were successfully simulated in 17 of the 22 Mars years of the available historic record. Statistical significance at the 99% level is obtained in a comparison of success rates between an occurrence model with stochastic forcing and those of the GCM forced by orbit-spin coupling. These results provide proof of concept for the orbit-spin coupling hypothesis as a factor contributing to the observed interannual variability of the weather and climate of Mars. |
| Title: | An initial assessment of the impact of postulated orbit-spin coupling on Mars dust storm variability in fully interactive dust simulations |
|---|---|
| Authors: | Newman, Claire E.; Lee, Chris; Mischna, Micheal A.; Richardson, Mark I.; Shirley, James H. |
| Affiliation: | AA(Aeolis Research, Pasadena, CA, United States), AB(University of Toronto, Toronto, Canada), AC(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States) |
| Journal: | Icarus, Volume 317, p. 649-668. |
| Publication Date: | Sept 2018 |
| Origin: | ELSEVIER |
| Keywords: | Atmospheres, dynamics, Mars, atmosphere |
| Abstract Copyright: | (c) 2018 The Authors |
| DOI: | https://doi.org/10.1016/j.icarus.2018.07.023 |
| Bibliographic Code: | 2019Icar..317..649N |
| Abstract: | A weak coupling between the rotational and orbital angular momenta of Mars has been postulated to produce a ‘coupling term acceleration’ (CTA) that accelerates the wind field and is asynchronous with the seasonal cycle of solar forcing (Shirley, 2017). This paper presents the first GCM simulations of a fully interactive dust cycle with the CTA included, enabling storm sizes, onset times and locations to be predicted. The inclusion of the CTA greatly augments interannual variability in the occurrence and timing of GDS, with the nature of the storm season strongly linked to the phasing and amplitude of the orbit-spin coupling. This dramatically improves the model's skill at predicting GDS and non-GDS Mars Years (MY) compared to a GCM without CTA forcing. The model is clearly wrong in only 4 out of 22 well-observed storm seasons and is able to capture the general onset time of most observed storms as well as some onset locations. In years when the CTA forcing has large positive amplitudes around perihelion, GDS with onset near perihelion occur due to a net strengthening of the single-cell Hadley circulation at this time, while earlier (or later) GDS are likely produced by more localized constructive interference between the CTA and tidal/topographic flows at a time of peak forcing amplitudes. The latter may be more sensitive to errors in the assumed surface dust availability, which may explain why a late GDS observed in MY 10 is not predicted. Depletion of surface dust in source regions by GDS in prior years may have prevented a GDS from occurring in the real MY 17, when a large GDS is incorrectly predicted. Early GDS are observed but not predicted in two MYs (12 and 25) with large negative CTA forcing amplitudes around perihelion, which may be associated with a lack of water cycle coupling in these simulations. Other missing physical processes, imperfect dust parameterizations or parameter values, the assumption of unlimited surface dust availability, or the wrong CTA strength may account for other mismatches. A GDS is predicted close to perihelion in the current storm season, MY34 (2018), with a smaller GDS predicted later next Mars year, MY35 (2020). The CTA forcing in MY 34 is very similar to that of MY 21, in which a GDS is correctly predicted by the model. |
| Title: | Age of martian air: Time scales for martian atmospheric transport |
|---|---|
| Authors: | Waugh, Darryn W.; Toigo, Anthony D.; Guzewich, Scott D. |
| Affiliation: | AA(Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, Maryland USA), AB(The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland USA), AC(NASA Goddard Spaceflight Center, Greenbelt, Maryland USA) |
| Journal: | Icarus, Volume 317, p. 148-157. |
| Publication Date: | August 2018 |
| Origin: | ELSEVIER |
| Keywords: | Atmospheres, dynamics, Mars, atmosphere |
| Abstract Copyright: | (c) 2018 Elsevier Inc. All rights reserved. |
| DOI: | https://doi.org/10.1016/j.icarus.2018.08.002 |
| Bibliographic Code: | 2019Icar..317..148W |
| Abstract: | MarsWRF general circulation model. The spatial distribution and seasonality of the mean age in low- and mid-latitudes broadly follow contours of the mean meridional circulation, with the mean age increasing from 0 at the surface to a maximum of 60–100 sols in the upper atmosphere. Substantially older mean ages (exceeding 300 sols) are found in polar regions, with oldest ages in the lower atmosphere (10–100 Pa), above a near-surface layer with very young ages (around 20 sols). The annual maximum ages occur around the equinoxes, and the age in the polar lower atmosphere decreases during the autumn to winter transition. This autumn-winter decrease in age occurs because of mixing of polar and mid-latitude air when the polar vortex exhibits an annulus of high potential vorticity (PV) with a local minimum near the pole. There is no autumn-winter decrease and old ages persist throughout autumn and winter in simulations with CO2 phase changes disabled, and thus no latent heating, where there is a monopolar vortex (i.e., a monotonic increase in PV from equator to pole) forms. The altitudinal and seasonal variations in the mean age indicates similar variations in the transport of dust into polar regions and the mixing of polar air (with, e.g., low water vapor and high ozone concentrations during winter) into mid-latitudes. |
| Title: | Dynamical processes of dust lifting in the northern mid-latitude region of Mars during the dust storm season |
|---|---|
| Authors: | Xiao, Jing; Chow, Kim-Chiu; Chan, Kwing-lam |
| Affiliation: | AA(Space Science Institute / Lunar and Planetary Science Laboratory, Macau University of Science and Technology, Administration Building, Block A, Avenida Wai Long, Taipa, Macau) |
| Journal: | Icarus, Volume 317, p. 94-103. |
| Publication Date: | July 2018 |
| Origin: | ELSEVIER |
| Keywords: | Atmospheres, dynamics, Mars, atmosphere |
| Abstract Copyright: | (c) 2018 Elsevier Inc. All rights reserved. |
| DOI: | https://doi.org/10.1016/j.icarus.2018.07.020 |
| Bibliographic Code: | 2019Icar..317...94X |
| Abstract: | The general circulation model MarsWRF has been used to simulate the regular dust climate on Mars. In particular, the double-peak episodes of dust storm activities during the dust storm season can be captured with the use of an active dust lifting scheme in the model. This study focuses on the dynamical processes of dust lifting in the northern mid-latitude region during these episodic periods. Wavelet analysis to the time series shows that dust lifting activities are associated with three distinct modes of variability. The first is the high frequency signal with a period of 0.5 to 1 sol, which is generally associated with the thermal tide. The second mode has the period about 7 sols, which is generally associated with the mid-latitude planetary waves. The third mode has the period over 50 sols, which is basically the signal of seasonal change in the region. Further analysis on wave numbers suggests that the dust lifting processes are dominated by the mode around wave number three. Results of sensitivity experiments also suggest that topography in the northern mid-latitude region is important to the lifting of dust in the period around 1 sol. |
| Title: | On the relationship between surface pressure, terrain elevation, and air temperature. Part I: The large diurnal surface pressure range at Gale Crater, Mars and its origin due to lateral hydrostatic adjustment |
|---|---|
| Authors: | Richardson, Mark I.; Newman, Claire E. |
| Affiliation: | AA(Aeolis Research, Pasadena, CA, United States) |
| Journal: | Planetary and Space Science, Volume 164, p. 132-157. |
| Publication Date: | July 2018 |
| Origin: | ELSEVIER |
| Keywords: | Atmospheres, dynamics, Mars, atmosphere |
| Abstract Copyright: | (c) 2018 The Authors |
| DOI: | https://doi.org/10.1016/j.pss.2018.07.003 |
| Bibliographic Code: | 2018P&SS..164..132R |
| Abstract: | The daily variation of surface pressure observed by the Curiosity Rover Environmental Monitoring Station (REMS) is both significantly larger than observed at other landing sites on Mars and larger than simulated for the Curiosity site by global circulation models (GCM). Mesoscale numerical models are able to simulate the large REMS daily pressure range, but only if they possess sufficiently high horizontal resolution (grid spacing <5 km); low resolution (120–500 km) GCM simulations typically generate daily ranges of about half the observed value. The pressure range in low resolution simulations corresponds to the large-scale thermal tides and the augmentation of this range in high resolution models is associable with mesoscale topographic and surface property variations in the Gale Crater region. We show that the augmentation is due to the lateral redistribution of mass required for the surface pressure distribution over topographic relief to remain approximately hydrostatic as the near-surface air temperature varies through the diurnal cycle. The physical origin and nature of this adjustment flow is explored. We provide a means of predicting the daily surface pressure due to lateral hydrostatic adjustment for any location and further show that this range is slightly reduced by the inability of the atmosphere to completely achieve hydrostaticity and by the thermal effects of induced flows. |
| Title: | The sensitivity of solsticial pauses to atmospheric ice and dust in the MarsWRF General Circulation Model |
|---|---|
| Authors: | Chris Lee, Mark I. Richardson, Claire E. Newman; Michael A. Mischna |
| Affiliation: | AA(Department of Physics, University of Toronto, St. George, Toronto, Ontario, M5S 1A7, Canada), AB(Aeolis Research, Pasadena, CA, United States), AC(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA) |
| Journal: | Icarus, Volume 311, p. 23-34. |
| Publication Date: | March 2018 |
| Origin: | ELSEVIER |
| Keywords: | Atmospheres, dynamics, Mars, atmosphere, clouds |
| Abstract Copyright: | (c) 2018 Elsevier Inc. All rights reserved. |
| DOI: | https://doi.org/10.1016/j.icarus.2018.03.019 |
| Bibliographic Code: | 2018Icar..311...23L |
| Abstract: | Mars exhibits less atmospheric variability at the solstices than it does during periods nearer the equinoxes. Much of this variability in air temperature and dust activity is attributable to a significant decrease in eastward traveling transient wave amplitudes in the lower atmosphere near the solstice. Pre- vious versions of the Mars Weather Research and Forecasting (MarsWRF) model using only dust radiative forcing have reproduced the nature but not the magnitude of this ‘solsticial pause’ in atmospheric vari- ability. In this paper, we use a version of MarsWRF that includes a fully-interactive dust and water cycle to simulate winter solsticial pauses under a range of dust and water ice conditions. The upgraded model specifically includes a new hybrid binned/two-moment microphysics model that simulates dust, water ice, and cloud condensation nuclei. The scheme tracks mass and number density for the three particle types throughout the atmosphere and allows advection by resolved winds, mixing by unresolved pro- cesses, and sedimentation that depends on particle size and density. Ice and dust particles interact with radiation in the atmosphere using a Mie scattering parameterization that allows for variable particle size and composition. Heterogeneous nucleation and condensation use an adaptive bin size scheme to accu- rately track the particle size during condensation and sublimation processes. All microphysical processes in the model are calculated within the dynamical timesteps using stability-guaranteed implicit calcula- tions with no sub-timestepping. The impact of the addition of water processes to the model was assessed by comparing simulations with only interactive dust (dry simulations) and ones with a fully-interactive dust and water cycle (wet simulations). In dry simulations with dust storms a solsticial pause occurs in the northern winter with a magnitude (or ‘depth’) that depends on the opacity of the southern summer dust storms. In wet simulations that include water ice and dust particles, deep solsticial pauses are found in both winter hemispheres. In all simulations that reproduce the solsticial pause, energy and instabil- ity analysis suggest that a decrease in baroclinic instability and increase in barotropic energy conversion occurs during the solsticial pause. In dry simulations the decrease in baroclinic instability is caused by increased dust opacity leading to increased thermal static stability. In wet simulations, additional opacity from local cap-edge ice clouds reduces the near surface wind shear and further inhibits baroclinic eddy growth. The wet simulations are in better agreement with observations and tend to support results from other models that include ice cloud radiative effects. |
| Title: | The cascade from local to global dust storms on Mars: Temporal and spatial thresholds on thermal and dynamical feedback |
|---|---|
| Authors: | Anthony D. Toigo; Mark I. Richardson; Huiqun Wang; Scott D. Guzewich; Claire E. Newman |
| Affiliation: | AA(The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland USA), AB(Aeolis Research, Pasadena, CA, United States), AC(Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, Massachusetts 02138, United States) AD(NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA) |
| Journal: | Icarus, Volume 302, p. 514-536. |
| Publication Date: | December 2017 |
| Origin: | ELSEVIER |
| Keywords: | Atmospheres, dynamics, Mars, atmosphere, dust |
| Abstract Copyright: | (c) 2017 Elsevier Inc. All rights reserved. |
| DOI: | https://doi.org/10.1016/j.icarus.2017.11.032 |
| Bibliographic Code: | 2018Icar..302..514T |
| Abstract: | We use the MarsWRF general circulation model to examine the temporal and spatial response of the at- mosphere to idealized local and regional dust storm radiative heating. The ability of storms to modify the atmosphere away from the location of dust heating is a likely prerequisite for dynamical feedbacks that aid the growth of storms beyond the local scale, while the ability of storms to modify the atmosphere after the cessation of dust radiative heating is potentially important in preconditioning the atmosphere prior to large scale storms. Experiments were conducted over a range of static, prescribed storm sizes, durations, optical depth strengths, locations, and vertical extents of dust heating. Our results show that for typical sizes (order 10^5 km 2 ) and durations (1–10 sols) of local dust storms, modification of the at- mosphere is less than the typical variability of the unperturbed (storm-free) state. Even if imposed on re- gional storm length scales (order 10^6 km 2 ), a 1-sol duration storm similarly does not significantly modify the background atmosphere. Only when imposed for 10 sols does a regional dust storm create a signifi- cant impact on the background atmosphere, allowing for the possibility of self-induced dynamical storm growth. These results suggest a prototype for how the subjective observational categorization of storms may be related to objective dynamical growth feedbacks that only become available to storms after they achieve a threshold size and duration, or if they grow into an atmosphere preconditioned by a prior large and sustained storm. |
| Title: | Winds measured by the Rover Environmental Monitoring Station (REMS) during the Mars Science Laboratory (MSL) rover’s Bagnold Dunes Campaign and comparison with numerical modeling using MarsWRF |
|---|---|
| Authors: | Claire E. Newman; Javier Gómez-Elvira; Mercedes Marin; Sara Navarro; Josefina Torres; Mark I. Richardson; J. Michael Battalio; Scott D. Guzewich; Robert Sullivan; Manuel de la Torre; Ashwin R. Vasavada; Nathan T. Bridges |
| Affiliation: | AA(Aeolis Research, Pasadena, CA, United States), AB(Centro de Astrobiología (CSIC-INTA), Torrejón de Ardoz, Madrid, Spain), AC(Texas A&M University, College Station, TX 77843, USA), AD(NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA), AE(Cornell University, Ithaca, NY 14853, USA), AF(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA), AG(Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA) |
| Journal: | Icarus, Volume 291, p. 203-231. |
| Publication Date: | December 2016 |
| Origin: | ELSEVIER |
| Keywords: | Atmospheres, dynamics, Mars, atmosphere, dunes |
| Abstract Copyright: | (c) 2016 Elsevier Inc. All rights reserved. |
| DOI: | http://dx.doi.org/10.1016/j.icarus.2016.12.016 |
| Bibliographic Code: | 2017Icar..291..203N |
| Abstract: | A high density of REMS wind measurements were collected in three science investigations during MSL’s Bagnold Dunes Campaign, which took place over ∼80 sols around southern winter solstice (Ls ∼90 °) and constituted the first in situ analysis of the environmental conditions, morphology, structure, and composition of an active dune field on Mars. The Wind Characterization Investigation was designed to fully characterize the near-surface wind field just outside the dunes and confirmed the primarily ups- lope/downslope flow expected from theory and modeling of the circulation on the slopes of Aeolis Mons in this season. The basic pattern of winds is ‘upslope’ (from the northwest, heading up Aeolis Mons) during the daytime ( ∼09:0 0–17:0 0 or 18:00) and ‘downslope’ (from the southeast, heading down Aeolis Mons) at night ( ∼20:00 to some time before 08:00). Between these times the wind rotates largely clock- wise, giving generally westerly winds mid-morning and easterly winds in the early evening. The timings of these direction changes are relatively consistent from sol to sol; however, the wind direction and speed at any given time shows considerable intersol variability. This pattern and timing is similar to predictions from the MarsWRF numerical model, run at a resolution of ∼490 m in this region, although the model predicts the upslope winds to have a stronger component from the E than the W, misses a wind speed peak at ∼09:00, and under-predicts the strength of daytime wind speeds by ∼2–4 m/s. The Namib Dune Lee Investigation reveals ‘blocking’ of northerly winds by the dune, leaving primarily a westerly com- ponent to the daytime winds, and also shows a broadening of the 1 Hz wind speed distribution likely associated with lee turbulence. The Namib Dune Side Investigation measured primarily daytime winds at the side of the same dune, in support of aeolian change detection experiments designed to put limits on the saltation threshold, and also appears to show the influence of the dune body on the local flow, though less clearly than in the lee. Using a vertical grid with lower resolution near the surface reduces the relative strength of nighttime winds predicted by MarsWRF and produces a peak in wind speed at ∼09:00, improving the match to the observed diurnal variation of wind speed, albeit with an offset in magnitude. The annual wind field predicted using this grid also provides a far better match to observa- tions of aeolian dune morphology and motion in the Bagnold Dunes. However, the lower overall wind speeds than observed and disagreement with the observed wind direction at ∼09:00 suggest that the problem has not been solved and that alternative boundary layer mixing schemes should be explored which may result in more mixing of momentum down to the near-surface from higher layers. These re- sults demonstrate a strong need for in situ wind data to constrain the setup and assumptions used in numerical models, so that they may be used with more confidence to predict the circulation at other times and locations on Mars. |
| Title: | The variability, structure and energy conversion of the northern hemisphere traveling waves simulated in a Mars general circulation model |
|---|---|
| Authors: | Wang, Huiqun; Toigo, Anthony D. |
| Affiliation: | AA(Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, Massachusetts 02138, United States), AB(Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland 20723, United States) |
| Journal: | Icarus, Volume 271, p. 207-221. |
| Publication Date: | Jun 2016 |
| Origin: | ELSEVIER |
| Keywords: | Atmospheres, dynamics, Mars, atmosphere |
| Abstract Copyright: | (c) 2016 Elsevier Inc. |
| DOI: | http://dx.doi.org/10.1016/j.icarus.2016.02.005http://bit.ly/2bk6MLt |
| Bibliographic Code: | 2016Icar..271..207W |
| Abstract: | Investigations of the variability, structure and energetics of the m = 1-3 traveling waves in the northern hemisphere of Mars are conducted with the MarsWRF general circulation model. Using a simple, annually repeatable dust scenario, the model reproduces many general characteristics of the observed traveling waves. The simulated m = 1 and m = 3 traveling waves show large differences in terms of their structures and energetics. For each representative wave mode, the geopotential signature maximizes at a higher altitude than the temperature signature, and the wave energetics suggests a mixed baroclinic-barotropic nature. There is a large contrast in wave energetics between the near-surface and higher altitudes, as well as between the lower latitudes and higher latitudes at high altitudes. Both barotropic and baroclinic conversions can act as either sources or sinks of eddy kinetic energy. Band-pass filtered transient eddies exhibit strong zonal variations in eddy kinetic energy and various energy transfer terms. Transient eddies are mainly interacting with the time mean flow. However, there appear to be non-negligible wave-wave interactions associated with wave mode transitions. These interactions include those between traveling waves and thermal tides and those among traveling waves. |
| Title: | Variations in Titan's dune orientations as a result of orbital forcing |
|---|---|
| Authors: | McDonald, George D.; Hayes, Alexander G.; Ewing, Ryan C.; Lora, Juan M.; Newman, Claire E.; Tokano, Tetsuya; Lucas, Antoine; Soto, Alejandro; Chen, Gang |
| Affiliation: | AA(School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30308, USA), AB(Department of Astronomy, Cornell University, Ithaca, NY 14853, USA), AC(Department of Geology and Geophysics, Texas A&M University, College Station, TX 77840, USA), AD(Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, CA 90095, USA), AE(Ashima Research, Pasadena, CA 91001, USA), AF(Institut für Geophysik und Meteorologie, Universität zu Köln, 50923 Köln, Germany), AG(AIM CEA-Saclay, Paris VII-Denis Diderot University, Paris 75013, France), AH(Southwest Research Institute, Boulder, CO 80032, USA), AI(Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14853, USA) |
| Journal: | Icarus, Volume 270, p. 197-210. |
| Publication Date: | May 2016 |
| Origin: | ELSEVIER |
| Keywords: | Titan, Titan, surface, Titan, atmosphere, Atmospheres, dynamics |
| Abstract Copyright: | (c) 2016 Elsevier Inc. |
| DOI: | http://dx.doi.org/10.1016/j.icarus.2015.11.036http://bit.ly/2bk6dBp |
| Bibliographic Code: | 2016Icar..270..197M |
| Abstract: | Wind-blown dunes are a record of the climatic history in Titan's equatorial region. Through modeling of the climatic conditions associated with Titan's historical orbital configurations (arising from apsidal precessions of Saturn's orbit), we present evidence that the orientations of the dunes are influenced by orbital forcing. Analysis of 3 Titan general circulation models (GCMs) in conjunction with a sediment transport model provides the first direct intercomparison of results from different Titan GCMs. We report variability in the dune orientations predicted for different orbital epochs of up to 70°. Although the response of the GCMs to orbital forcing varies, the orbital influence on the dune orientations is found to be significant across all models. Furthermore, there is near agreement among the two models run with surface topography, with 3 out of the 5 dune fields matching observation for the most recent orbital cycle. Through comparison with observations by Cassini, we find situations in which the observed dune orientations are in best agreement with those modeled for previous orbital configurations or combinations thereof, representing a larger portion of the cycle. We conclude that orbital forcing could be an important factor in governing the present-day dune orientations observed on Titan and should be considered when modeling dune evolution. |
| Title: | Atmospheric tides in Gale Crater, Mars |
|---|---|
| Authors: | Guzewich, Scott D.; Newman, C. E.; de la Torre Juárez, M.; Wilson, R. J.; Lemmon, M.; Smith, M. D.; Kahanpää, H.; Harri, A.-M. |
| Affiliation: | AA(CRESST and Planetary Systems Laboratory, NASA/GSFC, Greenbelt, MD 20771, United States), AB(Ashima Research, Pasadena, CA 91106, United States), AC(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, United States), AD(Geophysical Fluid Dynamics Laboratory, Princeton, NJ 08540, United States), AE(Texas A&M University, College Station, TX 77843, United States), AF(Planetary Systems Laboratory, NASA/GSFC, Greenbelt, MD 20771, United States), AG(Finnish Meteorological Institute, Helsinki, Finland), AH(Finnish Meteorological Institute, Helsinki, Finland) |
| Journal: | Icarus, Volume 268, p. 37-49. |
| Publication Date: | Apr 2016 |
| Origin: | ELSEVIER |
| Keywords: | Mars, atmosphere, Atmospheres, dynamics, Meteorology |
| Abstract Copyright: | (c) 2016 Elsevier Inc. |
| DOI: | http://dx.doi.org/10.1016/j.icarus.2015.12.028http://bit.ly/2boX8dS |
| Bibliographic Code: | 2016Icar..268...37G |
| Abstract: | Atmospheric tides are the primary source of daily air pressure variation at the surface of Mars. These tides are forced by solar heating of the atmosphere and modulated by the presence of atmospheric dust, topography, and surface albedo and thermal inertia. This results in a complex mix of sun-synchronous and non-sun-synchronous tides propagating both eastward and westward around the planet in periods that are integer fractions of a solar day. The Rover Environmental Monitoring Station on board the Mars Science Laboratory has observed air pressure at a regular cadence for over 1 Mars year and here we analyze and diagnose atmospheric tides in this pressure record. The diurnal tide amplitude varies from 26 to 63 Pa with an average phase of 0424 local true solar time, while the semidiurnal tide amplitude varies from 5 to 20 Pa with an average phase of 0929. We find that both the diurnal and semidiurnal tides in Gale Crater are highly correlated to atmospheric opacity variations at a value of 0.9 and to each other at a value of 0.77, with some key exceptions occurring during regional and local dust storms. We supplement our analysis with MarsWRF general circulation modeling to examine how a local dust storm impacts the diurnal tide in its vicinity. We find that both the diurnal tide amplitude enhancement and regional coverage of notable amplitude enhancement linearly scales with the size of the local dust storm. Our results provide the first long-term record of surface pressure tides near the martian equator. |
| Title: | Simulating Titan's methane cycle with the TitanWRF General Circulation Model |
|---|---|
| Authors: | Newman, Claire E.; Richardson, Mark I.; Lian, Yuan; Lee, Christopher |
| Affiliation: | AA(Aeolis Research, Suite 205, 600 North Rosemead Boulevard, Pasadena, CA 91107, USA), AB(Aeolis Research, Suite 205, 600 North Rosemead Boulevard, Pasadena, CA 91107, USA 0000-0001-9633-4141), AC(Aeolis Research, Suite 205, 600 North Rosemead Boulevard, Pasadena, CA 91107, USA), AD(Aeolis Research, Suite 205, 600 North Rosemead Boulevard, Pasadena, CA 91107, USA) |
| Journal: | Icarus, Volume 267, p. 106-134. |
| Publication Date: | Mar 2016 |
| Origin: | ELSEVIER |
| Keywords: | Titan, Titan, atmosphere, Atmospheres, dynamics, Atmospheres, structure, Meteorology |
| Abstract Copyright: | (c) 2016 Elsevier Inc. |
| DOI: | http://dx.doi.org/10.1016/j.icarus.2015.11.028http://bit.ly/22fPJwT |
| Bibliographic Code: | 2016Icar..267..106N |
| Abstract: | Observations provide increasing evidence of a methane hydrological cycle on Titan. Earth-based and Cassini-based monitoring has produced data on the seasonal variation in cloud activity and location, with clouds being observed at increasingly low latitudes as Titan moved out of southern summer. Lakes are observed at high latitudes, with far larger lakes and greater areal coverage in the northern hemisphere, where some shorelines extend down as far as 50°N. Rainfall at some point in the past is suggested by the pattern of flow features on the surface at the Huygens landing site, while recent rainfall is suggested by surface change. As with the water cycle on Earth, the methane cycle on Titan is both impacted by tropospheric dynamics and likely able to impact this circulation via feedbacks. Here we use the 3D TitanWRF General Circulation Model (GCM) to simulate Titan's methane cycle. In this initial work we use a simple large-scale condensation scheme with latent heat feedbacks and a finite surface reservoir of methane, and focus on large-scale dynamical interactions between the atmospheric circulation and methane, and how these impact seasonal changes and the long term (steady state) behavior of the methane cycle. We note five major conclusions: (1) Condensation and precipitation in the model is sporadic in nature, with interannual variability in its timing and location, but tends to occur in association with both (a) frequent strong polar upwelling during spring and summer in each hemisphere, and (b) the Inter-Tropical Convergence Zone (ITCZ), a region of increased convergence and upwelling due to the seasonally shifting Hadley cells. (2) An active tropospheric methane cycle affects the stratospheric circulation, slightly weakening the stratospheric superrotation produced. (3) Latent heating feedback strongly influences surface and near-surface temperatures, narrowing the latitudinal range of the ITCZ, and changing the distribution - and generally weakening the strength - of upwelling events. (4) TitanWRF favors low latitude 'cloudiness' around northern spring equinox as the ITCZ moves from south to north across the equator, versus the opposite time of year. (5) TitanWRF produces drying of low and mid latitudes with net transport of surface methane to high latitudes, and shows persistent hemispheric asymmetry in the methane cycle such that the favored pole for surface methane is the one with winter occurring closest to perihelion. |
| Title: | The impact of surface dust source exhaustion on the martian dust cycle, dust storms and interannual variability, as simulated by the MarsWRF General Circulation Model |
|---|---|
| Authors: | Newman, Claire E.; Richardson, Mark I. |
| Affiliation: | AA(Ashima Research, Suite 104, 600 South Lake Avenue, Pasadena, CA 91001, USA), AB(Ashima Research, Suite 104, 600 South Lake Avenue, Pasadena, CA 91001, USA) |
| Journal: | Icarus, Volume 257, p. 47-87. |
| Publication Date: | Sep 2015 |
| Origin: | ELSEVIER |
| Keywords: | Mars, atmosphere, surface, Atmospheres, dynamics, climate |
| Abstract Copyright: | (c) 2015 Elsevier Inc. |
| DOI: | http://dx.doi.org/10.1016/j.icarus.2015.03.030http://bit.ly/2bk6IeS |
| Bibliographic Code: | 2015Icar..257...47N |
| Abstract: | Observations of albedo on Mars suggest a largely invariant long-term mean surface dust distribution, but also reveal variations on shorter (seasonal to annual) timescales, particularly associated with major dust storms. We study the impact of finite surface dust availability on the dust cycle in the MarsWRF General Circulation Model (GCM), which uses radiatively active dust with parameterized 'dust devil' and wind stress dust lifting to enable the spontaneous production of dust storms, and tracks budgets of dust lifting, deposition, and total surface dust inventory. We seek a self-consistent, long-term 'steady state' dust cycle for present day Mars, consisting of (a) a surface dust distribution that varies from year to year but is constant longer-term and in balance with current dust redistribution processes, and (b) a fixed set of dust lifting parameters that continue to produce major storms for this distribution of surface dust. We relax the GCM's surface dust inventory toward this steady state using an iterative process, in which dust lifting rate parameters are increased as progressively more surface sites are exhausted of dust. Late in the equilibration process, the GCM exhibits quasi-steady state behavior in which few new surface grid points are exhausted during a 60 year period with constant dust lifting parameters. Complex regional-scale dust redistribution occurs on time-scales from less than seasonal to decadal, and the GCM generates regional to global dust storms with many realistic features. These include merging regional storms, cross-equatorial storms, and the timing and location of several storm types, though very early major storms and large amounts of late storm activity are not reproduced. Surface dust availability in key onset and growth source regions appears vital for 'early' major storms, with replenishment of these regions required before another large storm can occur, whereas 'late' major storms appear primarily dependent on atmospheric variability. For the parameter space explored, no simulation achieves a steady state with continuing major storms lasting longer than 60 years when a constant wind stress lifting threshold is used. However, such a long-term steady state is achieved when a variable threshold is introduced, in which the threshold increases as dust is removed. This negative feedback on lifting slows it sufficiently for a balance to be produced between dust removal and re-deposition, even in key source regions for major storms. One concern is that the long-term surface dust distributions produced in these simulations show significant differences to the observed northern hemisphere albedo map, in particular predicting Tharsis and NE Arabia to be relatively dust-free. Although some observed high albedo regions may not have significant mobile dust, others likely have a dust cover several meters thick. The mismatches may reflect deficiencies in the GCM or the iterative process used, or the existence of ancient deep dust deposits formed during a past climate epoch. |
| Title: | General circulation models of the dynamics of Pluto's volatile transport on the eve of the New Horizons encounter |
|---|---|
| Authors: | Toigo, Anthony D.; French, Richard G.; Gierasch, Peter J.; Guzewich, Scott D.; Zhu, Xun; Richardson, Mark I. |
| Affiliation: | AA(Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, United States), AB(Wellesley College, Wellesley, MA 02492, United States), AC(Astronomy Department, Cornell University, Ithaca, NY 14853, United States), AD(NASA Goddard Space Flight Center, Greenbelt, MD 20771, United States), AE(Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, United States), AF(Ashima Research, Pasadena, CA 91106, United States) |
| Journal: | Icarus, Volume 254, p. 306-323. |
| Publication Date: | Jul 2015 |
| Origin: | ELSEVIER |
| Keywords: | Pluto, atmosphere, Atmospheres, dynamics |
| Abstract Copyright: | (c) 2015 Elsevier Inc. |
| DOI: | http://dx.doi.org/10.1016/j.icarus.2015.03.034http://bit.ly/2b2IhC3 |
| Bibliographic Code: | 2015Icar..254..306T |
| Abstract: | Pluto's atmospheric dynamics occupy an interesting regime in which the radiative time constant is quite long, the combined effects of high obliquity and a highly eccentric orbit can produce strong seasonal variations in atmospheric pressure, and the strong coupling between the atmosphere and volatile transport on the surface results in atmospheric flows that are quite sensitive to surface and subsurface properties that at present are poorly constrained by direct observations. In anticipation of the New Horizons encounter with the Pluto system in July 2015, we present a Pluto-specific three-dimensional general circulation model (GCM), PlutoWRF, incorporating the most accurate current radiative transfer models of Pluto's atmosphere, a physically robust treatment of nitrogen volatile transport, and the flexibility to accommodate richly detailed information about the surface and subsurface conditions as new data become available. We solve for a physically self-consistent, equilibrated combination of surface, subsurface, and atmospheric conditions to specify the boundary conditions and initial state values for each GCM run. This is accomplished using two reduced versions of PlutoWRF: a two-dimensional surface volatile exchange model to specify the properties of surface nitrogen ice and the initial atmospheric surface pressure, and a one-dimensional radiative-conductive-convective model that uses the two-dimensional model predictions to determine the corresponding global-mean atmospheric thermal profile. We illustrate the capabilities of PlutoWRF in predicting Pluto's general circulation, thermal state, and volatile transport of nitrogen by calculating the dynamical response of Pluto's atmosphere, based on four different idealized models of Pluto's surface ice distribution from Young (Young, L.A. [2013]. Astrophys. J. 766, L22) and Hansen et al. (Hansen, C.J., Paige, D.A., Young, L.A. [2015]. Icarus 246, 183). Our GCM runs typically span 30 years, from 1985 to 2015, covering the period from the discovery of Pluto's atmosphere to present. For most periods simulated, zonal winds are strongly forced by a gradient wind balance, relaxing in later (recent) years to an angular momentum conservation balance of the seasonal polar cap sublimation flow. Near-surface winds generally follow a sublimation flow from the sunlit polar cap to the polar night cap, with a Coriolis turning of the wind as the air travels from pole to pole. We demonstrate the strong contribution of nitrogen sublimation and deposition to Pluto's atmospheric circulation. As New Horizons data become available, PlutoWRF can be used to construct models of Pluto's atmospheric dynamics and surface wind regimes more constrained by physical observations. |
| Title: | Martian atmospheric collapse: Idealized GCM studies |
|---|---|
| Authors: | Soto, Alejandro; Mischna, Michael; Schneider, Tapio; Lee, Christopher; Richardson, Mark |
| Affiliation: | AA(Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA), AB(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA), AC(Department of Earth Sciences, ETH Zurich, Switzerland), AD(Ashima Research, Pasadena, CA 91106, USA), AE(Ashima Research, Pasadena, CA 91106, USA) |
| Journal: | Icarus, Volume 250, p. 553-569. |
| Publication Date: | Apr 2015 |
| Origin: | ELSEVIER |
| Keywords: | Mars, climate, atmosphere, polar caps, Atmospheres, evolution, dynamics |
| Abstract Copyright: | (c) 2015 Elsevier Inc. |
| DOI: | http://dx.doi.org/10.1016/j.icarus.2014.11.028http://bit.ly/1QKB9Hl |
| Bibliographic Code: | 2015Icar..250..553S |
| Abstract: | Global energy balance models of the martian atmosphere predict that, for a range of total CO2 inventories, the CO2 atmosphere may condense until a state with a permanent polar cap is reached. This process, which is commonly referred to as atmospheric collapse, may limit the time available for physical and chemical weathering. The global energy balance models that predict atmospheric collapse represent the climate using simplified parameterizations for atmospheric processes such as radiative transfer and atmospheric heat transport. However, a more detailed representation of these atmospheric processes is critical when the atmosphere is near a transition, such as the threshold for collapse. Therefore, we use the Mars Weather Research and Forecasting (MarsWRF) general circulation model (GCM) to investigate how the explicit representation of meridional heat transport and more detailed radiative transfer affects the onset of atmospheric collapse. Using MarsWRF, we find that previous energy balance modeling underestimates the range of CO2 inventories for which the atmosphere collapses and that the obliquity of Mars determines the range of CO2 inventories that can collapse. For a much larger range of CO2 inventories than expected, atmospheric heat transport is insufficient to prevent the atmospheric collapse. We show that the condensation of CO2 onto Olympus Mons and adjacent mountains generates a condensation flow. This condensation flow syphons energy that would otherwise be transported poleward, which helps explain the large range of CO2 inventories for which the atmosphere collapses. |
| Title: | Feasibility Studies on Guidance and Global Path Planning for Wind-Assisted Montgolfière in Titan |
|---|---|
| Authors: | Fathpour, Nanaz; Blackmore, Lars; Kuwata, Yoshiaki; Assad, Christopher; Wolf, Michael T.; Newman, Claire; Elfes, Alberto; Reh, Kim |
| Journal: | IEEE Systems Journal, vol. 8, issue 4, pp. 1112-1125 |
| Publication Date: | Dec 2014 |
| Origin: | CROSSREF |
| DOI: | http://dx.doi.org/10.1109/JSYST.2013.2282700http://bit.ly/1pnplEY |
| Bibliographic Code: | 2014ISysJ...8.1112F |
| Abstract: | Not Available |
| Title: | Threshold for sand mobility on Mars calibrated from seasonal variations of sand flux |
|---|---|
| Authors: | Ayoub, F.; Avouac, J.-P.; Newman, C. E.; Richardson, M. I.; Lucas, A.; Leprince, S.; Bridges, N. T. |
| Affiliation: | AA(Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, MC 100-23, Pasadena, California 91125, USA; fayoub@gps.caltech.edu), AB(), AC(Ashima Research, 600 South Lake Avenue, Suite 104, Pasadena, California 91106, USA), AD(Ashima Research, 600 South Lake Avenue, Suite 104, Pasadena, California 91106, USA), AE(Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, MC 100-23, Pasadena, California 91125, USA), AF(Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, MC 100-23, Pasadena, California 91125, USA), AG(Space Department, 200-W230, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, USA) |
| Journal: | Nature Communications, Volume 5, id. 5096 (2014). |
| Publication Date: | Sep 2014 |
| Origin: | NATURE |
| Abstract Copyright: | (c) 2014: Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved. |
| DOI: | http://dx.doi.org/10.1038/ncomms6096 http://bit.ly/24AtjKG |
| Bibliographic Code: | 2014NatCo...5.5096A |
| Abstract: | Coupling between surface winds and saltation is a fundamental factor governing geological activity and climate on Mars. Saltation of sand is crucial for both erosion of the surface and dust lifting into the atmosphere. Wind tunnel experiments along with measurements from surface meteorology stations and modelling of wind speeds suggest that winds should only rarely move sand on Mars. However, evidence for currently active dune migration has recently accumulated. Crucially, the frequency of sand-moving events and the implied threshold wind stresses for saltation have remained unknown. Here we present detailed measurements of Nili Patera dune field based on High Resolution Imaging Science Experiment images, demonstrating that sand motion occurs daily throughout much of the year and that the resulting sand flux is strongly seasonal. Analysis of the seasonal sand flux variation suggests an effective threshold for sand motion for application to large-scale model wind fields (1-100 km scale) of τs=0.01±0.0015 N m-2. |
| Title: | Thermal tides during the 2001 Martian global-scale dust storm |
|---|---|
| Authors: | Guzewich, Scott D.; Wilson, R. John; McConnochie, Timothy H.; Toigo, Anthony D.; Banfield, Donald J.; Smith, Michael D. |
| Affiliation: | AA(NASA Goddard Spaceflight Center, Greenbelt, Maryland USA), AB(Geophysical Fluid Dynamics Laboratory NOAA, Princeton, New Jersey USA), AC(Department of Astronomy, University of Maryland, College Park, Maryland USA), AD(Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland USA), AE(Center for Radiophysics and Space Research, Cornell University, Ithaca, New York USA), AF(NASA Goddard Spaceflight Center, Greenbelt, Maryland USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 119, Issue 3, pp. 506-519 |
| Publication Date: | Mar 2014 |
| Origin: | WILEY |
| Keywords: | Mars, global dust storm, tides, waves |
| Abstract Copyright: | ©2014. American Geophysical Union. All Rights Reserved. |
| DOI: | http://dx.doi.org/10.1002/2013JE004502http://bit.ly/2bk6DaK |
| Bibliographic Code: | 2014JGRE..119..506G |
| Abstract: | The 2001 (Mars Year 25) global dust storm radically altered the dynamics of the Martian atmosphere. Using observations from the Thermal Emission Spectrometer onboard the Mars Global Surveyor spacecraft and MarsWRF general circulation model simulations, we examine the changes to thermal tides and planetary waves caused by the storm. We find that the extratropical diurnal migrating tide is dramatically enhanced during the storm, particularly in the southern hemisphere, reaching amplitudes of more than 20 K. The tropical diurnal migrating tide is weakened to almost undetectable levels. The diurnal Kelvin waves are also significantly weakened, particularly during the period of global expansion at Ls = 200°-210°. In contrast, the westward propagating diurnal wavenumber 2 tide strengthens to 4-8 K at altitudes above 30 km. The wavenumber 1 stationary wave reaches amplitudes of 10-12 K at 50°-70°N, far larger than is typically seen during this time of year. The phase of this stationary wave and the enhancement of the diurnal wavenumber 2 tide appear to be responses to the high-altitude westward propagating equatorial wavenumber 1 structure in dust mixing ratio observed during the storm in previous works. This work provides a global picture of dust storm wave dynamics that reveals the coupling between the tropics and high-latitude wave responses. We conclude that the zonal distribution of thermotidal forcing from atmospheric aerosol concentration is as important to understanding the atmospheric wave response as the total global mean aerosol optical depth. |
| Title: | Constraints on Mars' recent equatorial wind regimes from layered deposits and comparison with general circulation model results |
|---|---|
| Authors: | Sefton-Nash, E.; Teanby, N. A.; Newman, C.; Clancy, R. A.; Richardson, M. I. |
| Affiliation: | AA(Department of Earth and Space Sciences, University of California Los Angeles, 595 Charles Young Drive East, Los Angeles, CA 90095, USA), AB(School of Earth Sciences, University of Bristol, Queen's Road, Bristol BS8 1RJ, UK), AC(Ashima Research, 600 S. Lake Ave., Suite 104, Pasadena, CA 91106, USA), AD(School of Earth Sciences, University of Bristol, Queen's Road, Bristol BS8 1RJ, UK), AE(Ashima Research, 600 S. Lake Ave., Suite 104, Pasadena, CA 91106, USA) |
| Journal: | Icarus, Volume 230, p. 81-95. |
| Publication Date: | Feb 2014 |
| Origin: | ELSEVIER |
| Abstract Copyright: | (c) 2014 Elsevier Inc. |
| DOI: | http://dx.doi.org/10.1016/j.icarus.2013.11.014http://bit.ly/1TQXbh1 |
| Bibliographic Code: | 2014Icar..230...81S |
| Abstract: | Aeolian modification has been a fundamental surface process on Mars throughout the Amazonian. Orientations of aeolian features such as bedforms and yardangs are controlled by the prevailing wind regime during the feature's formation. Therefore, observation of recently formed bedform orientations provides a way to probe Mars' recent wind regime and constrain/test general circulation models (GCMs). We collect statistical distributions of transverse bedform and yardang azimuths at nine sites on Mars, and compare measured feature orientations to those predicted by using vector wind field output from the MarsWRF GCM. We focus on layered deposits because their erodible nature makes them applicable to determination of Mars' modern wind regime. Our methods of mapping from the long-term wind field to predicted feature orientations include consideration of wind stress thresholds for sand movement to occur, sand flux equations, and the direction of maximum gross bedform-normal transport. We find that all methods examined typically agree with each other to within ˜15°, though there are some exceptions using high order wind stress weightings with multi-directional annual wind fields. Generally, use of higher wind stress thresholds produces improved matches to bedform orientations. Comparison of multiple yardang orientations to annually variable wind fields is accomplished by inspection of directional maxima in modelled wind vector frequency distributions. Yardangs match well to model predictions and sub-populations in close proximity to each other are shown to match individual directional maxima in GCM output for a single site, implying that topographic effects may produce very localised unidirectional wind fields unresolved by the GCM. |
| Title: | Growth and form of the mound in Gale Crater, Mars: Slope wind enhanced erosion and transport |
|---|---|
| Authors: | Kite, Edwin S.; Lewis, Kevin W.; Lamb, Michael P.; Newman, Claire E.; Richardson, Mark I. |
| Affiliation: | AA(California Institute of Technology), AB(Princeton University), AC(California Institute of Technology), AE(Ashima Research) |
| Journal: | Geology, vol. 41, p. 543-546 |
| Publication Date: | May 2013 |
| Origin: | AUTHOR |
| Bibliographic Code: | 2013Geo....41..543K |
| Abstract: | Ancient sediments provide archives of climate and habitability on Mars. Gale Crater, the landing site for the Mars Science Laboratory (MSL), hosts a 5-km-high sedimentary mound (Mount Sharp/Aeolis Mons). Hypotheses for mound formation include evaporitic, lacustrine, fluviodeltaic, and aeolian processes, but the origin and original extent of Gale’s mound is unknown. Here we show new measurements of sedimentary strata within the mound that indicate ˜3° outward dips oriented radially away from the mound center, inconsistent with the first three hypotheses. Moreover, although mounds are widely considered to be erosional remnants of a once crater-filling unit, we find that the Gale mound’s current form is close to its maximal extent. Instead we propose that the mound’s structure, stratigraphy, and current shape can be explained by growth in place near the center of the crater mediated by wind-topography feedbacks. Our model shows how sediment can initially accrete near the crater center far from crater-wall katabatic winds, until the increasing relief of the resulting mound generates mound-flank slope winds strong enough to erode the mound. The slope wind enhanced erosion and transport (SWEET) hypothesis indicates mound formation dominantly by aeolian deposition with limited organic carbon preservation potential, and a relatively limited role for lacustrine and fluvial activity. Morphodynamic feedbacks between wind and topography are widely applicable to a range of sedimentary and ice mounds across the Martian surface, and possibly other planets. |
| Title: | The impact of a realistic vertical dust distribution on the simulation of the Martian General Circulation |
|---|---|
| Authors: | Guzewich, Scott D.; Toigo, Anthony D.; Richardson, Mark I.; Newman, Claire E.; Talaat, Elsayed R.; Waugh, Darryn W.; McConnochie, Timothy H. |
| Affiliation: | AA(NASA Goddard Spaceflight Center, Greenbelt, Maryland USA), AB(The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland USA), AC(Ashima Research, Pasadena, California USA), AD(Ashima Research, Pasadena, California USA), AE(The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland USA), AF(Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, Maryland USA), AG(Department of Astronomy, University of Maryland, College Park, Maryland USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 118, Issue 5, pp. 980-993 |
| Publication Date: | May 2013 |
| Origin: | WILEY |
| Keywords: | Mars Atmosphere, Dust, GCM Modeling |
| Abstract Copyright: | ©2013. American Geophysical Union. All Rights Reserved. |
| DOI: | http://dx.doi.org/10.1002/jgre.20084http://bit.ly/1ncyr61 |
| Bibliographic Code: | 2013JGRE..118..980G |
| Abstract: | Limb-scanning observations with the Mars Climate Sounder and Thermal Emission Spectrometer (TES) have identified discrete layers of enhanced dust opacity well above the boundary layer and a mean vertical structure of dust opacity very different from the expectation of well-mixed dust in the lowest 1-2 scale heights. To assess the impact of this vertical dust opacity profile on atmospheric properties, we developed a TES limb-scan observation-based three-dimensional and time-evolving dust climatology for use in forcing general circulation models (GCMs). We use this to force the MarsWRF GCM and compare with simulations that use a well-mixed (Conrath-ν) vertical dust profile and Mars Climate Database version 4 (MCD) horizontal distribution dust opacity forcing function. We find that simulated temperatures using the TES-derived forcing yield a 1.18 standard deviation closer match to TES temperature retrievals than a MarsWRF simulation using MCD forcing. The climatological forcing yields significant changes to many large-scale features of the simulated atmosphere. Notably the high-latitude westerly jet speeds are 10-20 m/s higher, polar warming collar temperatures are 20-30 K warmer near northern winter solstice and tilted more strongly poleward, the middle and lower atmospheric meridional circulations are partially decoupled, the migrating diurnal tide exhibits destructive interference and is weakened by 50% outside of equinox, and the southern hemisphere wave number 1 stationary wave is strengthened by up to 4 K (45%). We find the vertical dust distribution is an important factor for Martian lower and middle atmospheric thermal structure and circulation that cannot be neglected in analysis and simulation of the Martian atmosphere. |
| Title: | Zonal wavenumber three traveling waves in the northern hemisphere of Mars simulated with a general circulation model |
|---|---|
| Authors: | Wang, Huiqun; Richardson, Mark I.; Toigo, Anthony D.; Newman, Claire E. |
| Affiliation: | AA(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA), AB(Ashima Research, Pasadena, CA 91101, USA), AC(Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA), AD(Ashima Research, Pasadena, CA 91101, USA) |
| Journal: | Icarus, Volume 223, Issue 2, p. 654-676. |
| Publication Date: | Apr 2013 |
| Origin: | ELSEVIER |
| Abstract Copyright: | Elsevier Inc. |
| DOI: | http://dx.doi.org/10.1016/j.icarus.2013.01.004http://bit.ly/12XkM2Q |
| Bibliographic Code: | 2013Icar..223..654W |
| Abstract: | Observations suggest a strong correlation between curvilinear shaped traveling dust storms (observed in wide angle camera images) and eastward traveling zonal wave number m = 3 waves (observed in thermal data) in the northern mid and high latitudes during the fall and winter. Using the MarsWRF General Circulation Model, we have investigated the seasonality, structure and dynamics of the simulated m = 3 traveling waves and tested the hypothesis that traveling dust storms may enhance m = 3 traveling waves under certain conditions.Our standard simulation using a prescribed "MGS dust scenario" can capture the observed major wave modes and strong near surface temperature variations before and after the northern winter solstice. The same seasonal pattern is also shown by the simulated near surface meridional wind, but not by the normalized surface pressure. The simulated eastward traveling 1.4 < T < 10 sol m = 3 waves are confined near the surface in terms of the temperature perturbation, EP flux and eddy available potential energy, and they extend higher in terms of the eddy winds and eddy kinetic energy. The signature of the simulated m = 3 traveling waves is stronger in the near surface meridional wind than in the near surface temperature field.Compared with the standard simulation, our test simulations show that the prescribed m = 3 traveling dust blobs can enhance the simulated m = 3 traveling waves during the pre- and post-solstice periods when traveling dust storms are frequently observed in images, and that they have negligible effect during the northern winter solstice period when traveling dust storms are absent. The enhancement is even greater in our simulation when dust is concentrated closer to the surface. Our simulations also suggest that dust within the 45-75°N band is most effective at enhancing the simulated m = 3 traveling waves.There are multiple factors influencing the strength of the simulated m = 3 traveling waves. Among those, our study suggests that weaker near surface static stability, larger near surface baroclinic parameter, and wave-form dust forcing for latitudinally extended dust storms are favorable. Further study is needed to fully understand the importance of these factors and others. |
| Title: | Effects of obliquity and water vapor/trace gas greenhouses in the early martian climate |
|---|---|
| Authors: | Mischna, Michael A.; Baker, Victor; Milliken, Ralph; Richardson, Mark; Lee, Christopher |
| Affiliation: | AA(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California USA), AB(Department of Planetary Sciences, Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona USA), AC(Department of Geological Sciences, Brown University, Providence, Rhode Island USA), AD(Ashima Research, Pasadena, California USA), AE(Ashima Research, Pasadena, California USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 118, Issue 3, pp. 560-576 |
| Publication Date: | Mar 2013 |
| Origin: | WILEY |
| Keywords: | early Mars, sulfur, volcanism, obliquity, greenhouse effect, MarsWRF |
| Abstract Copyright: | ©2013. American Geophysical Union. All Rights Reserved. |
| DOI: | http://dx.doi.org/10.1002/jgre.20054http://bit.ly/1plx6LD |
| Bibliographic Code: | 2013JGRE..118..560M |
| Abstract: | We explore possible mechanisms for the generation of warm, wet climates on early Mars as a result of greenhouse warming by both water vapor and periodic volcanic trace emissions. The presence of both water vapor (a strong greenhouse gas) and other trace greenhouse gases (such as SO2) in a predominantly CO2 atmosphere may act, under certain conditions, to elevate surface temperatures above the freezing point of liquid water, at least episodically. Variations in obliquity are explored to investigate whether these periodic variations in insolation at Mars can broaden the regions or seasons where warm temperatures can exist. We use the Mars Weather Research and Forecasting general circulation model to perform several simulations of the conditions of the early martian atmosphere containing these gases and find global temperatures to be cooler than the elevated levels suggested by at least one recent study by Johnson et al. (2008). While achieving temperatures above 273 K globally remains challenging, the additional warming by greenhouse gases under certain obliquity states can permit for widespread seasonally warm conditions, which can help to explain the presence of fluvial surface features (e.g., valley networks) and hydrous minerals of post-Noachian age, a period when alternate methods do not convincingly explain the sustainability of liquid water. Furthermore, we find that global warming can be achieved with the presence of a darker surface globally, which is consistent with both widespread exposure of unweathered basaltic bedrock or the presence of a large surface ocean or sea. |
| Title: | Development of a fast, accurate radiative transfer model for the Martian atmosphere, past and present |
|---|---|
| Authors: | Mischna, Michael A.; Lee, Christopher; Richardson, Mark |
| Affiliation: | AA(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA), AB(Ashima Research, Pasadena, California, USA), AC(Ashima Research, Pasadena, California, USA) |
| Journal: | Journal of Geophysical Research, Volume 117, Issue E10, CiteID E10009 |
| Publication Date: | Oct 2012 |
| Origin: | AGU |
| Keywords: | Atmospheric Composition and Structure: Planetary atmospheres (5210, 5405, 5704), Planetary Sciences: Astrobiology: Planetary atmospheres, clouds, and hazes (0343), Planetary Sciences: Solid Surface Planets: Atmospheres (0343, 1060) |
| Abstract Copyright: | (c) 2012: American Geophysical Union |
| DOI: | http://dx.doi.org/10.1029/2012JE004110http://bit.ly/W82l7h |
| Bibliographic Code: | 2012JGRE..11710009M |
| Abstract: | We present details of an approach to creating a k-distribution radiative transfer model (KDM) for use in the Martian atmosphere. Such models preserve the accuracy of more rigorous line-by-line models, but are orders of magnitude faster, and can be effectively implemented in 3-D general circulation models. The approach taken here is sufficiently generalized that it can be employed for atmospheres of any arbitrary composition and mass, and demonstrations are provided for simulated atmospheres with a present-day Martian surface pressure (∼6 mb) and a putative thick early Mars atmosphere (∼500 mb), both with and without atmospheric water vapor. KDM-derived absorption coefficients are placed into a look-up table at a set of gridded points in pressure, temperature and atmospheric composition, and a tri-linear interpolation scheme is used to obtain the coefficients appropriate for the local atmospheric conditions. These coefficients may then be used within any of a variety of commonly used flux solvers to obtain atmospheric heating rates. A series of validation tests are performed with the KDM for both present-day and early Mars atmospheric conditions, and the model is compared against several other widely used radiative transfer schemes, including several used in contemporary general circulation models. These validation results identify weaknesses in some other approaches and demonstrate the efficacy of the KDM, providing a rigorous test of these types of models for use in the Martian atmosphere. A demonstration of results obtained by implementing the KDM in a Mars general circulation model is provided. |
| Title: | The impact of resolution on the dynamics of the martian global atmosphere: Varying resolution studies with the MarsWRF GCM |
|---|---|
| Authors: | Toigo, Anthony D.; Lee, Christopher; Newman, Claire E.; Richardson, Mark I. |
| Affiliation: | AA(The Johns Hopkins University, Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, USA), AB(Ashima Research, Suite 104, 600 South Lake Ave., Pasadena, CA 91106, USA), AC(Ashima Research, Suite 104, 600 South Lake Ave., Pasadena, CA 91106, USA), AD(Ashima Research, Suite 104, 600 South Lake Ave., Pasadena, CA 91106, USA) |
| Journal: | Icarus, Volume 221, Issue 1, p. 276–288. |
| Publication Date: | Aug 2012 |
| Origin: | ELSEVIER |
| Abstract Copyright: | Elsevier Inc. |
| DOI: | http://dx.doi.org/10.1016/j.icarus.2012.07.020http://bit.ly/PUT9VM |
| Bibliographic Code: | 2012Icar..221..276T |
| Abstract: | We investigate the sensitivity of the circulation and thermal structure of the martian atmosphere to numerical model resolution in a general circulation model (GCM) using the martian implementation (MarsWRF) of the planetWRF atmospheric model. We provide a description of the MarsWRF GCM and use it to study the global atmosphere at horizontal resolutions from 7.5 9 to 0.5 0.5, encompassing the range from standard Mars GCMs to global mesoscale modeling. We find that while most of the gross-scale features of the circulation (the rough location of jets, the qualitative thermal structure, and the major large-scale features of the surface level winds) are insensitive to horizontal resolution over this range, several major features of the circulation are sensitive in detail. The northern winter polar circulation shows the greatest sensitivity, showing a continuous transition from a smooth polar winter jet at low resolution, to a distinct vertically ‘‘split’’ jet as resolution increases. The separation of the lower and middle atmosphere polar jet occurs at roughly 10 Pa, with the split jet structure developing in concert with the intensification of meridional jets at roughly 10 Pa and above 0.1 Pa. These meridional jets appear to represent the separation of lower and middle atmosphere mean overturning circulations (with the former being consistent with the usual concept of the ‘‘Hadley cell’’). Further, the transition in polar jet structure is more sensitive to changes in zonal than meridional horizontal resolution, suggesting that representation of small-scale wave-mean flow interactions is more important than fine-scale representation of the meridional thermal gradient across the polar front. Increasing the horizontal resolution improves the match between the modeled thermal structure and the Mars Climate Sounder retrievals for northern winter high latitudes. While increased horizontal resolution also improves the simulation of the northern high latitudes at equinox, even the lowest model resolution considered here appears to do a good job for the southern winter and southern equinoctial pole (although in detail some discrepancies remain). These results suggest that studies of the northern winter jet (e.g., transient waves and cyclogenesis) will be more sensitive to global model resolution that those of the south (e.g., the confining dynamics of the southern polar vortex relevant to studies of argon transport). For surface winds, the major effect of increased horizontal resolution is in the superposition of circulations forced by local-scale topography upon the large-scale surface wind patterns. While passive predictions of dust lifting are generally insensitive to model horizontal resolution when no lifting threshold is considered, increasing the stress threshold produces significantly more lifting in higher resolution simulations with the generation of finer-scale, higher-stress winds due primarily to better-resolved topography. Considering the positive feedbacks expected for radiatively active dust lifting, we expect this bias to increase when such feedbacks are permitted. |
| Title: | Winds and tides of Ligeia Mare, with application to the drift of the proposed time TiME (Titan Mare Explorer) capsule |
|---|---|
| Authors: | Lorenz, Ralph D.; Tokano, Tetsuya; Newman, Claire E. |
| Affiliation: | AA(JHU Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, USA), AB(Institut für Geophysik und Meteorologie, Universität zu Köln, Albertus-Magnus-Platz, 50923 Köln, Germany), AC(Ashima Research, 600 S. Lake Avenue Suite 104, Pasadena, CA 91106, USA) |
| Journal: | Planetary and Space Science, Volume 60, Issue 1, p. 72-85. |
| Publication Date: | Jan 2012 |
| Origin: | ELSEVIER |
| Abstract Copyright: | (c) 2012 Elsevier Ltd |
| DOI: | http://dx.doi.org/10.1016/j.pss.2010.12.009http://bit.ly/1TQXbh1 |
| Bibliographic Code: | 2012P&SS...60...72L |
| Abstract: | We use two independent General Circulation Models (GCMs) to estimate surface winds at Titan’s Ligeia Mare (78° N, 250° W), motivated by a proposed mission to land a floating capsule in this ∼500 km hydrocarbon sea. The models agree on the overall magnitude (∼0.5-1 m/s) and seasonal variation (strongest in summer) of windspeeds, but details of seasonal and diurnal variation of windspeed and direction differ somewhat, with the role of surface exchanges being more significant than that of gravitational tides in the atmosphere. We also investigate the tidal dynamics in the sea using a numerical ocean dynamics model: assuming a rigid lithosphere, the tidal amplitude is up to ∼0.8 m. Tidal currents are overall proportional to the reciprocal of depth-with an assumed central depth of 300 m, the characteristic tidal currents are ∼1 cm/s, with notable motions being a slosh between Ligeia’s eastern and western lobes, and a clockwise flow pattern. We find that a capsule will drift at approximately one tenth of the windspeed, unless measures are adopted to augment the drag areas above or below the waterline. Thus motion of a floating capsule is dominated by the wind, and is likely to be several km per Earth day, a rate that will be readily measured from Earth by radio navigation methods. In some instances, the wind vector rotates diurnally such that the drift trajectory is epicyclic. |
| Title: | Demonstration of ensemble data assimilation for Mars using DART, MarsWRF, and radiance observations from MGS TES |
|---|---|
| Authors: | Lee, C.; Lawson, W. G.; Richardson, M. I.; Anderson, J. L.; Collins, N.; Hoar, T.; Mischna, M. |
| Affiliation: | AA(Ashima Research, Pasadena, California, USA); AB(Point Carbon, Washington, D. C., USA); AC(Ashima Research, Pasadena, California, USA); AD(Institute for Mathematics Applied to Geosciences, National Center for Atmospheric Research, Boulder, Colorado, USA); AE(Institute for Mathematics Applied to Geosciences, National Center for Atmospheric Research, Boulder, Colorado, USA); AF(Institute for Mathematics Applied to Geosciences, National Center for Atmospheric Research, Boulder, Colorado, USA); AG(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA) |
| Journal: | Journal of Geophysical Research, Volume 116, Issue E11, CiteID E11011 |
| Publication Date: | Nov 2011 |
| Origin: | AGU |
| Keywords: | Global Change: Global climate models (3337, 4928), Informatics: Community modeling frameworks, Informatics: Data assimilation, integration and fusion, Mathematical Geophysics: Numerical approximations and analysis (4260), Planetary Sciences: Solar System Objects: Mars |
| Abstract Copyright: | (c) 2011: American Geophysical Union |
| DOI: | http://dx.doi.org/10.1029/2011JE003815http://bit.ly/Yknr7L |
| Bibliographic Code: | 2011JGRE..11611011L |
| Abstract: | We describe a global atmospheric data assimilation scheme that has been adapted for use with a Martian General Circulation Model (GCM), with the ultimate goal of creating globally and temporally interpolated “reanalysis” data sets from planetary atmospheric observations. The system uses the Data Assimilation Research Testbed (DART) software to apply an Ensemble Kalman Filter (EnKF) to the MarsWRF GCM. Specific application to Mars also required the development of a radiance forward model for near-nadir Thermal Emission Spectrometer (TES) observations. Preliminary results from an assimilation of 40 sols of TES radiance data, taken around Ls = 150° (August 1999, Mars Year 24), are provided. 1.3 million TES observations are ingested and used to improve the state prediction by the GCM, with bias and error reductions obtained throughout the state vector. Results from the assimilation suggest steepening of the latitudinal and vertical thermal gradients with concurrent strengthening of the mid-latitude zonal jets, and a slower recession of the southern polar ice edge than predicted by the unaided GCM. Limitations of the prescribed dust model are highlighted by the presence of an atmospheric radiance bias. Preliminary results suggest the prescribed dust vertical profile might not be suitable for all seasons, in accordance with more recent observations of the vertical distribution of dust by the Mars Climate Sounder. |
| Title: | Stratospheric superrotation in the TitanWRF model |
|---|---|
| Authors: | Newman, Claire E.; Lee, Christopher; Lian, Yuan; Richardson, Mark I.; Toigo, Anthony D. |
| Affiliation: | AA(Ashima Research, Suite 104, 600 South Lake Avenue, Pasadena, CA 91106, USA), AB(Ashima Research, Suite 104, 600 South Lake Avenue, Pasadena, CA 91106, USA), AC(Ashima Research, Suite 104, 600 South Lake Avenue, Pasadena, CA 91106, USA), AD(Ashima Research, Suite 104, 600 South Lake Avenue, Pasadena, CA 91106, USA), AE(The Johns Hopkins University, Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, USA) |
| Journal: | Icarus, Volume 213, Issue 2, p. 636-654. |
| Publication Date: | Jun 2011 |
| Origin: | ELSEVIER |
| Abstract Copyright: | Elsevier Inc. |
| DOI: | http://dx.doi.org/10.1016/j.icarus.2011.03.025http://bit.ly/TZAPqA |
| Bibliographic Code: | 2011Icar..213..636N |
| Abstract: | TitanWRF general circulation model simulations performed without sub-grid-scale horizontal diffusion of momentum produce roughly the observed amount of superrotation in Titan's stratosphere. We compare these results to Cassini-Huygens measurements of Titan's winds and temperatures, and predict temperature and winds at future seasons. We use angular momentum and transformed Eulerian mean diagnostics to show that equatorial superrotation is generated during episodic angular momentum 'transfer events' during model spin-up, and maintained by similar (yet shorter) events once the model has reached steady state. We then use wave and barotropic instability analysis to suggest that these transfer events are produced by barotropic waves, generated at low latitudes then propagating poleward through a critical layer, thus accelerating low latitudes while decelerating the mid-to-high latitude jet in the late fall through early spring hemisphere. Finally, we identify the dominant waves responsible for the transfers of angular momentum close to northern winter solstice during spin-up and at steady state. Problems with our simulations include peak latitudinal temperature gradients and zonal winds occurring ˜60 km lower than observed by Cassini CIRS, and no reduction in zonal wind speed around 80 km, as was observed by Huygens. While the latter may have been due to transient effects (e.g. gravity waves), the former suggests that our low (˜420 km) model top is adversely affecting the circulation near the jet peak, and/or that we require active haze transport in order to correctly model heating rates and thus the circulation. Future work will include running the model with a higher top, and including advection of a haze particle size distribution. |
| Title: | Atmospheric modeling of Mars methane surface releases |
|---|---|
| Authors: | Mischna, Michael A.; Allen, Mark; Richardson, Mark I.; Newman, Claire E.; Toigo, Anthony D. |
| Affiliation: | AA(Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., M/S 183-401, Pasadena, CA 91109, USA), AB(Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., M/S 183-401, Pasadena, CA 91109, USA; Also, Division of Geological and Planetary Sciences, California Institute of Technology, MC 150-21, 1200 E. California Blvd. Pasadena, CA 91125, USA), AC(Division of Geological and Planetary Sciences, California Institute of Technology, MC 150-21, 1200 E. California Blvd. Pasadena, CA 91125, USA; Present address: Ashima Research, 600 S. Lake Ave, Suite 303, Pasadena, CA 91106, USA), AD(Division of Geological and Planetary Sciences, California Institute of Technology, MC 150-21, 1200 E. California Blvd. Pasadena, CA 91125, USA; Present address: Ashima Research, 600 S. Lake Ave, Suite 303, Pasadena, CA 91106, USA), AE(Cornell University, Department of Astronomy, Ithaca, NY 14853, USA; Present address: The Johns Hopkins University, Applied Physics Laboratory, 11100 Johns Hopkins Rd., Laurel, MD 20723, USA) |
| Journal: | Planetary and Space Science, Volume 59, Issue 2-3, p. 227-237. |
| Publication Date: | Feb 2011 |
| Origin: | ELSEVIER |
| Abstract Copyright: | Elsevier Ltd |
| DOI: | http://dx.doi.org/10.1016/j.pss.2010.07.005http://bit.ly/WsimoA |
| Bibliographic Code: | 2011P&SS...59..227M |
| Abstract: | We utilize the MarsWRF general circulation model (GCM) to address the behavior of gas plumes in the Martian atmosphere, with the specific goal of characterizing the source of the recently identified methane detection in the Martian atmosphere. These observations have been interpreted as the release of methane from localized surface sources with spatial and temporal variabilities. Due to the limited temporal coverage of ground-based observations, we use a GCM to simulate the development of passive atmospheric plumes over relevant timescales. The observations can be reproduced best if the release occurred just before the time of observation—no more than 1-2 sols earlier—and if this release were nearly instantaneous rather than a slow, steady emission. Furthermore, it requires a source region spanning a broad latitudinal range rather than a point emission. While the accuracy of our conclusions about this specific methane release scenario is limited by the uncertainties inherent in GCM simulations of the Martian atmosphere, our findings regarding generalized plume behavior are robust, and illustrate the potential power of numerical modeling for constraining plume source conditions. |
| Title: | On the mystery of the perennial carbon dioxide cap at the south pole of Mars |
|---|---|
| Authors: | Guo, Xin; Richardson, Mark Ian; Soto, Alejandro; Toigo, Anthony |
| Affiliation: | AA(Planetary Science, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA); AB(Ashima Research, Pasadena, California, USA); AC(Planetary Science, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA); AD(Center for Radiophysics and Space Research, Cornell University, Ithaca, New York, USA) |
| Journal: | Journal of Geophysical Research, Volume 115, Issue E4, CiteID E04005 |
| Publication Date: | Apr 2010 |
| Origin: | AGU |
| Keywords: | Atmospheric Composition and Structure: Planetary atmospheres (5210, 5405, 5704), Planetary Sciences: Solar System Objects: Mars, Planetary Sciences: Solid Surface Planets: Polar regions, Planetary Sciences: Solid Surface Planets: Atmospheres (0343, 1060), Planetary Sciences: Solid Surface Planets: Ices |
| DOI: | http://dx.doi.org/10.1029/2009JE003382http://bit.ly/Tha6XP |
| Bibliographic Code: | 2010JGRE..115.4005G |
| Abstract: | A perennial ice cap has long been observed near the south pole of Mars. The surface of this cap is predominantly composed of carbon dioxide ice. The retention of a CO2 ice cap results from the surface energy balance of the latent heat, solar radiation, surface emission, subsurface conduction, and atmospheric sensible heat. While models conventionally treat surface CO2 ice using constant ice albedos and emissivities, such an approach fails to predict the existence of a perennial cap. Here we explore the role of the insolation-dependent ice albedo, which agrees well with Viking, Mars Global Surveyor, and Mars Express albedo observations. Using a simple parameterization within a general circulation model, in which the albedo of CO2 ice responds linearly to the incident solar insolation, we are able to predict the existence of a perennial CO2 cap at the observed latitude and only in the southern hemisphere. Further experiments with different total CO2 inventories, planetary obliquities, and surface boundary conditions suggest that the location of the residual cap may exchange hemispheres favoring the pole with the highest peak insolation. |
| Title: | Fitting the Viking lander surface pressure cycle with a Mars General Circulation Model |
|---|---|
| Authors: | Guo, Xin; Lawson, W. Gregory; Richardson, Mark I.; Toigo, Anthony |
| Affiliation: | AA(Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA); AB(Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA); AC(Ashima Research, Pasadena, California, USA); AD(Center for Radiophysics and Space Research, Cornell University, Ithaca, New York, USA) |
| Journal: | Journal of Geophysical Research, Volume 114, Issue E7, CiteID E07006 |
| Publication Date: | Jul 2009 |
| Origin: | AGU |
| Keywords: | Atmospheric Composition and Structure: Planetary atmospheres (5210, 5405, 5704), Planetary Sciences: Solar System Objects: Mars, Planetary Sciences: Solid Surface Planets: Polar regions, Planetary Sciences: Solid Surface Planets: Atmospheres (0343, 1060), Planetary Sciences: Solid Surface Planets: Ices |
| DOI: | http://dx.doi.org/10.1029/2008JE003302http://bit.ly/V2IEgh |
| Bibliographic Code: | 2009JGRE..114.7006G |
| Abstract: | We present a systematic attempt to fit the Viking lander surface pressure cycle using a Mars General Circulation Model, MarsWRF. Following the earlier study by Wood and Paige (1992) using a one-dimensional model, high-precision fitting was achieved by tuning five time-independent parameters: the albedo and emissivity of the seasonal caps of the two hemispheres and the total CO2 inventory in the atmosphere frost system. We used a linear iterative method to derive the best fit parameters: albedo of the northern cap = 0.795, emissivity of the northern cap = 0.485, albedo of the southern cap = 0.461, emissivity of the southern cap = 0.785, and total CO2 mass = 2.83 × 1016 kg. If these parameters are used in MarsWRF, the smoothed surface pressure residual at the VL1 site is always smaller than several Pascal through a year. As in other similar studies, the best fit parameters do not match well with the current estimation of the seasonal cap radiative properties, suggesting that important physics contributing to the energy balance not explicitly included in MarsWRF have been effectively aliased into the derived parameters. One such effect is likely the variation of thermal conductivity with depth in the regolith due to the presence of water ice. Including such a parameterization in the fitting process improves the reasonableness of the best fit cap properties, mostly improving the emissivities. The conductivities required in the north to provide the best fit are higher than those required in the south. A completely physically reasonable set of fit parameters could still not be attained. Like all prior published GCM simulations, none of the cases considered are capable of predicting a residual southern CO2 cap. |
| Title: | Sulfur-induced greenhouse warming on early Mars |
|---|---|
| Authors: | Johnson, Sarah Stewart; Mischna, Michael A.; Grove, Timothy L.; Zuber, Maria T. |
| Affiliation: | AA(Department of Earth, Atmospheric and Planetary Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA), AB(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA), AC(Department of Earth, Atmospheric and Planetary Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA), AD(Department of Earth, Atmospheric and Planetary Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA) |
| Journal: | Journal of Geophysical Research, Volume 113, Issue E8, CiteID E08005 |
| Publication Date: | Aug 2008 |
| Origin: | AGU |
| Keywords: | Planetary Sciences: Solar System Objects: Mars, Planetary Sciences: Solid Surface Planets: Atmospheres (0343, 1060), Biogeosciences: Sulfur cycling, Atmospheric Processes: Climate change and variability (1616, 1635, 3309, 4215, 4513) |
| DOI: | http://dx.doi.org/10.1029/2007JE002962http://bit.ly/RiwrZq |
| Bibliographic Code: | 2008JGRE..113.8005J |
| Abstract: | Mineralogical, geological, geophysical, and isotopic data recently returned from Mars suggest that the delivery of sulfur gases to the atmosphere may have played a significant role in the planet's early evolution. Using the Gusev Crater basalt composition and a batch melting model, we obtain a high sulfur solubility, approximately 1400 ppm, in Martian mantle melts. We proceed to explore different scenarios for the pulsed degassing of sulfur volatiles associated with the emplacement of near-surface dikes during the late Noachian or early Hesperian, when surface pressures are thought to be substantially higher than present. We investigate background Martian atmospheres of 50 and 500 mbar CO2 with varying abundances of H2O and sulfur volatiles (H2S and SO2 mixing ratios of 10-3 to 10-6). Results suggest that these sulfur volatile influxes, alone, could have been responsible for greenhouse warming up to 25 K above that caused by CO2. Including additional water vapor feedback, this process could have raised the early surface temperature above the freezing point for brines and possibly allowed transient liquid water on the Martian surface. Each temperature rise was likely to have been short-lived, however, due to brief residence times for sulfur volatiles in an optically thin atmosphere. |
| Title: | Two aerodynamic roughness maps derived from Mars Orbiter Laser Altimeter (MOLA) data and their effects on boundary layer properties in a Mars general circulation model (GCM) |
|---|---|
| Authors: | Heavens, N. G.; Richardson, M. I.; Toigo, A. D. |
| Affiliation: | AA(Division of the Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA); AB(Division of the Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA); AC(Center for Radiophysics and Space Research, Cornell University, Ithaca, New York, USA) |
| Journal: | Journal of Geophysical Research, Volume 113, Issue E2, CiteID E02014 |
| Publication Date: | Feb 2008 |
| Origin: | AGU |
| Keywords: | Planetary Sciences: Solar System Objects: Mars, Planetary Sciences: Solid Surface Planets: Atmospheres (0343, 1060), Planetary Sciences: Solid Surface Planets: Surface materials and properties, Atmospheric Processes: Boundary layer processes, Atmospheric Processes: Global climate models (1626, 4928) |
| Abstract Copyright: | (c) 2008: American Geophysical Union |
| DOI: | http://dx.doi.org/10.1029/2007JE002991http://bit.ly/UXryQt |
| Bibliographic Code: | 2008JGRE..113.2014H |
| Abstract: | Mechanical (forced convective) and free convective turbulent heat and momentum transfer in the lower atmosphere of a terrestrial planet has some dependence on the roughness characteristics of the surface, often quantified in terms of a single roughness parameter which is then used to calculate the coefficients that govern heat and momentum transport between the surface and the boundary layer. We take two different approaches for deriving this aerodynamic roughness parameter for Martian surfaces using data from the Mars Orbiter Laser Altimeter. We then use these two different roughness maps to force the boundary layer in a Mars general circulation model, primarily investigating differences in temperatures and the pressure cycle between the two simulations. While the pressure cycle does not vary significantly, spring and summer high-latitude temperatures are somewhat sensitive to the input roughness conditions. Daytime temperatures may vary up to 10 K seasonally, though zonally and annually averaged daytime temperatures vary only by ~1 K. Our results can be explained by the dominance of mechanical over convective turbulent heat transfer processes on Mars. These simulations, however, use a prescribed atmospheric dust distribution and thus only provide a minimum estimate of the uncertainty in boundary layer temperatures because of this plausible range of aerodynamic roughness parameters. Since surface roughness determines the threshold wind velocity for dust lifting we anticipate a much larger effect of the aerodynamic roughness parameter on temperatures when the dust distribution is allowed to vary according to predicted lifting and transport. |
| Title: | PlanetWRF: A General Purpose, Local to Global Numerical Model for Planetary Atmospheric and Climate Dynamics |
|---|---|
| Authors: | Richardson, M. I.; Toigo, A. D; Newman, C. E. |
| Journal: | Journal of Geophysical Research, Volume 112, Issue E9, CiteID E09001 |
| Publication Date: | Sep 2007 |
| DOI: | http://dx.doi.org/10.1029/2006JE002825http://bit.ly/TmLSvq |
| Abstract: | A new planetary atmospheric numerical model, “planetWRF,” has been developed by modifying the Weather Research and Forecasting (WRF) model. The model has generalized map projection, multiscale, and nesting capabilities, blurring the distinction between global and mesoscale models and enabling investigation of coupling between processes on all scales, including global. The model can also be run in one, two, or three dimensions. The conversion of the dynamical core for global application by altering the map projection grid and the boundary conditions as well as conversion of the physics parameterizations and constants for planetary application are described. Validation of the global dynamical core through use of standard forcing scenarios is presented. Example results from a series of simulations for Mars, Titan, and Venus are shown to demonstrate that the model performs well for a variety of planets and operating modes (microscale, mesoscale, and global scale). |