2019
| 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: | Damping of gravity waves by kinetic processes in Jupiter's thermosphere |
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| Authors: | Lian, Yuan; Yelle, Roger V. |
| Affiliation: | AA(Aeolis Research, Pasadena, CA, USA), AB(The University of Arizona, Tucson, AZ, USA) |
| Journal: | Icarus, Volume 329, p. 222-245. |
| Publication Date: | Sep 2019 |
| Origin: | Elsevier BV |
| Keywords: | Jupiter, Atmosphere, Thermosphere, Gravity waves, Rovibrational damping |
| Abstract Copyright: | (c) 2019 Elsevier Inc. |
| DOI: | https://doi.org/10.1016/j.icarus.2019.04.001 |
| Bibliographic Code: | 2019Icar..329..222L |
| Abstract: | We employ a linearized full-wave model to show that the rovibrational damping (hereafter, RV damping) of gravity waves is an important source of atmospheric heating, which needs to be taken into account when modeling the wave processes in the jovian thermospheres. We find that RV damping of internal gravity waves becomes strong when the wave frequencies approach the thermal collision frequency. RV damping, compared to the damping by molecular viscosity and thermal diffusivity, can effectively lower the damping altitudes for waves with large frequencies, and requires larger upward wave energy fluxes to produce prescribed wave amplitudes for these waves. Particularly, the energy deposited by RV damping, viscous and thermal dissipation of the two waves identified in measurements by the Atmospheric Structure Instrument (ASI) on the Galileo Probe can produce a maximum temperature about 40 K higher than those in previous studies. We further demonstrate RV damping effect on the mesoscale gravity wave observed during the New Horizons flyby on Jupiter. Under the influence of RV damping, this wave has the vertical wavelength and damping altitude comparable to those of wave 2 retrieved from the ASI observations. The energy dissipation of these three observed waves, if coexist, should provide sufficient heating to produce the observed mean temperature between 357 km and 700 km above 1 bar. |
| Title: | Vertical and horizontal heterogeneity of atmospheric dust loading in northern Gale Crater, Mars |
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| 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: | The Methane Diurnal Variation and Microseepage Flux at Gale Crater, Mars as Constrained by the ExoMars Trace Gas Orbiter and Curiosity Observations |
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| 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: | Effects of the MY34/2018 Global Dust Storm as Measured by MSL REMS in Gale Crater |
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| Authors: | Viúdez-Moreiras, D.; Newman, C. E.; de la Torre, M.; Martínez, G.; Guzewich, S.; Lemmon, M.; Pla-García, J.; Smith, M. D.; Harri, A.-M.; Genzer, M.; Vicente-Retortillo, A.; Lepinette, A.; Rodriguez-Manfredi, J. A.; Vasavada, A. R.; Gómez-Elvira, J. |
| Affiliation: | AA(Centro de Astrobiología (CSIC-INTA) and Spanish National Institute for Aerospace Technology (INTA), Madrid, Spain), AB(Aeolis Research, Pasadena, CA USA), AC(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AD(University of Michigan, Ann Arbor, MI USA), AE(NASA Goddard Spaceflight Center, Greenbelt, MD USA), AF(Space Science Institute, College Station, TX USA), AG(Centro de Astrobiología (CSIC-INTA) and Spanish National Institute for Aerospace Technology (INTA), Madrid, Spain), AH(NASA Goddard Spaceflight Center, Greenbelt, MD USA), AI(Space Research and Observation Technologies, Finnish Meteorological Institute, Helsinki, Finland), AJ(Space Research and Observation Technologies, Finnish Meteorological Institute, Helsinki, Finland), AK(University of Michigan, Ann Arbor, MI USA), AL(Centro de Astrobiología (CSIC-INTA) and Spanish National Institute for Aerospace Technology (INTA), Madrid, Spain), AM(Centro de Astrobiología (CSIC-INTA) and Spanish National Institute for Aerospace Technology (INTA), Madrid, Spain), AN(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AO(Centro de Astrobiología (CSIC-INTA) and Spanish National Institute for Aerospace Technology (INTA), Madrid, Spain) |
| Journal: | Journal of Geophysical Research: Planets, Volume 124, Issue 7, pp. 1899-1912. |
| Publication Date: | Jul 2019 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Global Dust Storm, Martian atmosphere, REMS instrument, Mars Science Laboratory |
| Abstract Copyright: | ©2019. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2019JE005985 |
| Bibliographic Code: | 2019JGRE..124.1899V |
| Abstract: | The Rover Environmental Monitoring Station (REMS) instrument is on board NASA's Mars Science Laboratory (MSL) Curiosity rover. REMS has been measuring surface pressure, air, and ground brightness temperature, relative humidity, and ultraviolet (UV) irradiance since MSL's landing in 2012. In Mars Year (MY) 34 (2018) a global dust storm reached Gale Crater at L<SUB>s</SUB> 190°. REMS offers a unique opportunity to better understand the impact of a global dust storm on local environmental conditions, which complements previous observations by the Viking landers and Mars Exploration Rovers. All atmospheric variables measured by REMS are strongly affected albeit at different times. During the onset phase, the daily maximum UV radiation decreased by 90% between sols 2075 (opacity 1) and 2085 (opacity 8.5). The diurnal range in ground and air temperatures decreased by 35 and 56 K, respectively, with also a diurnal-average decrease of 2 and 4 K respectively. The maximum relative humidity, which occurs right before sunrise, decreased to below 5%, compared with prestorm values of up to 29%, due to the warmer air temperatures at night, while the inferred water vapor abundance suggests an increase during the storm. Between sols 2085 and 2130, the typical nighttime stable inversion layer was absent near the surface as ground temperatures remained warmer than near-surface air temperatures. Finally, the frequency domain behavior of the diurnal pressure cycle shows a strong increase in the strength of the semidiurnal and terdiurnal modes peaking after the local opacity maximum, also suggesting differences in the dust abundance inside and outside Gale. |
| Title: | Methane seasonal cycle at Gale Crater on Mars consistent with regolith adsorption and diffusion |
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| Authors: | Moores, John E.; Gough, Raina V.; Martinez, German M.; Meslin, Pierre-Yves; Smith, Christina L.; Atreya, Sushil K.; Mahaffy, Paul R.; Newman, Claire E.; Webster, Christopher R. |
| Affiliation: | AA(Centre for Research in Earth and Space Science, York University, Toronto, Ontario, Canada ;), AB(University of Colorado, Boulder, CA, USA), AC(University of Michigan, Ann Arbor, MI, USA), AD(Université Paul Sabatier, Toulouse, France), AE(Centre for Research in Earth and Space Science, York University, Toronto, Ontario, Canada), AF(University of Michigan, Ann Arbor, MI, USA), AG(NASA-Goddard, Greenbelt, MD, USA), AH(Aeolis Research, Pasadena, CA, USA), AI(Caltech-JPL, Pasadena, CA, USA) |
| Journal: | Nature Geoscience, Volume 12, Issue 5, pp. 321-325. |
| Publication Date: | May 2019 |
| Origin: | Springer Science and Business Media LLC |
| Abstract Copyright: | © The Author(s), under exclusive licence to Springer Nature Limited 2019 |
| DOI: | https://doi.org/10.1038/s41561-019-0313-y |
| Bibliographic Code: | 2019NatGe..12..321M |
| Abstract: | A strong, repeatable seasonal cycle in the background methane mixing ratio has been observed at the Gale Crater landing site of the Mars Science Laboratory rover with the Tunable Laser Spectrometer of the Sample Analysis at Mars instrument. However, as of yet, no physical process has been proposed that can explain both the timing and amplitude of the observations. Here we show that a one-dimensional numerical model considering adsorption onto and diffusion through the regolith can reproduce the variation, including a phase lag, if the regolith is impregnated with methane from a prior plume or supplied from below by microseepage. Combining the model results with geological constraints, we estimate that the amount of microseepage at Gale is at most 3 × 10<SUP>-5</SUP> tonnes km<SUP>-2</SUP> yr<SUP>-1</SUP>. Gale's unique dynamical environment makes such seeps easier to detect in surface sampling measurements. Over most of the Martian surface, atmospheric mixing is stronger or atmospheric transport more effective, and we expect the amplitude of the seasonal cycle to be smaller for the same strength of seep. |
| Title: | Gale surface wind characterization based on the Mars Science Laboratory REMS dataset. Part I: Wind retrieval and Gale's wind speeds and directions |
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| Authors: | Viúdez-Moreiras, D.; Gómez-Elvira, J.; Newman, C. E.; Navarro, S.; Marin, M.; Torres, J.; de la Torre-Juárez, M.; MSL Team |
| Affiliation: | AA(Centro de Astrobiología (CSIC-INTA) & Spanish National Institute for Aerospace Technology (INTA) Torrejón de Ardoz, Madrid, Spain), AB(Centro de Astrobiología (CSIC-INTA) & Spanish National Institute for Aerospace Technology (INTA) Torrejón de Ardoz, Madrid, Spain), AC(Aeolis Research, 600 N. Rosemead Ave., Suite 205, Pasadena, CA 91106, USA), AD(Centro de Astrobiología (CSIC-INTA) & Spanish National Institute for Aerospace Technology (INTA) Torrejón de Ardoz, Madrid, Spain), AE(Centro de Astrobiología (CSIC-INTA) & Spanish National Institute for Aerospace Technology (INTA) Torrejón de Ardoz, Madrid, Spain), AF(Centro de Astrobiología (CSIC-INTA) & Spanish National Institute for Aerospace Technology (INTA) Torrejón de Ardoz, Madrid, Spain), AG(Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA) |
| Journal: | Icarus, Volume 319, p. 909-925. |
| Publication Date: | Feb 2019 |
| Origin: | Elsevier BV |
| Keywords: | Martian atmosphere modeling, Atmospheric characterization, Wind speeds and directions, NASA Mars Science Laboratory, REMS data |
| Abstract Copyright: | (c) 2019 Elsevier Inc. |
| DOI: | https://doi.org/10.1016/j.icarus.2018.10.011 |
| Bibliographic Code: | 2019Icar..319..909V |
| Abstract: | The characterization of Martian surface winds as a function of time of day and season at one location can increase our knowledge of Mars surface conditions and assist in planning for future unmanned and manned missions. Martian surface winds vary greatly with location, and even at a particular landing site show a high degree of diurnal, seasonal, and interannual variability. Thus characterizing surface wind speeds and directions requires a long time series, which is rarely obtained on Mars. The Rover Environmental Monitoring Station (REMS) instrument on the Mars Science Laboratory (MSL) rover has been measuring Martian winds since 2012, thus has provided more than two Martian years of wind data at the first Martian landing site to have significant topography, in the trench of Gale Crater. Unfortunately, likely debris impacts during landing damaged the wind sensor, making it difficult to extract useful wind data. The first part of this paper presents a new retrieval that allows "good" wind measurements to be extracted from the raw dataset obtained under such conditions. In addition, a characterization of wind speeds and directions in Gale Crater is presented, after processing the full dataset of wind data in order to obtain the representative winds for different diurnal timeslots and seasons. Results suggest complex wind patterns and great variability depending on local time and season. Also, a significant influence by the synoptic scale circulation in the wind patterns is observed, although the local-scale circulation is suggested to be the major contributor to the observed surface winds in Gale Crater. |
| Title: | Gale surface wind characterization based on the Mars Science Laboratory REMS dataset. Part II: Wind probability distributions |
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| Authors: | Viúdez-Moreiras, D.; Gómez-Elvira, J.; Newman, C. E.; Navarro, S.; Marin, M.; Torres, J.; de la Torre-Juárez, M.; MSL Team |
| Affiliation: | AA(Centro de Astrobiología (CSIC-INTA), Spanish National Institute for Aerospace Technology (INTA) Torrejón de Ardoz, Madrid, Spain), AB(Centro de Astrobiología (CSIC-INTA), Spanish National Institute for Aerospace Technology (INTA) Torrejón de Ardoz, Madrid, Spain), AC(Aeolis Research, 600 N. Rosemead Ave., Suite 205, Pasadena, CA 91106, USA), AD(Centro de Astrobiología (CSIC-INTA), Spanish National Institute for Aerospace Technology (INTA) Torrejón de Ardoz, Madrid, Spain), AE(Centro de Astrobiología (CSIC-INTA), Spanish National Institute for Aerospace Technology (INTA) Torrejón de Ardoz, Madrid, Spain), AF(Centro de Astrobiología (CSIC-INTA), Spanish National Institute for Aerospace Technology (INTA) Torrejón de Ardoz, Madrid, Spain), AG(Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA) |
| Journal: | Icarus, Volume 319, p. 645-656. |
| Publication Date: | Feb 2019 |
| Origin: | Elsevier BV |
| Keywords: | Martian atmosphere modeling, Atmospheric characterization, Weibull wind distribution, NASA Mars science laboratory, REMS data |
| Abstract Copyright: | (c) 2019 Elsevier Inc. |
| DOI: | https://doi.org/10.1016/j.icarus.2018.10.010 |
| Bibliographic Code: | 2019Icar..319..645V |
| Abstract: | The characterization of Martian surface wind speed as a function of time of day and season at one location can increase our knowledge of Mars surface conditions and assist in planning for future unmanned and manned missions, since the probability of the wind speed exceeding a given value is often required for both engineering and geophysical applications. Wind speeds are also useful for assessing the aeolian impact of the circulation. The Rover Environmental Monitoring Station (REMS) instrument on the Mars Science Laboratory (MSL) rover has been measuring Martian winds since 2012, thus has provided more than two Mars years of wind data in the first Martian landing site with significant topography. Unfortunately, dust debris during the MSL landing stage damaged the sensor, making difficult to extract useful wind data. This paper complements the characterization performed in the companion paper, by producing a wind speed characterization based on probability distribution models. Significant diurnal and seasonal wind speed variability is found, due to complex interactions between the synoptic flow, the regional and local slope winds and microscale flow around MSL. The highest wind speed probabilities are found in general during the midday period, particularly around the equinoxes. In addition, the REMS data suggest strong flows during the summer nighttime, which could be related to the increased aeolian activity detected then by MSL. |
| Title: | An initial assessment of the impact of postulated orbit-spin coupling on Mars dust storm variability in fully interactive dust simulations |
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| Authors: | Newman, C. E.; Lee, C.; Mischna, M. A.; Richardson, M. I.; Shirley, J. H. |
| Affiliation: | AA(Aeolis Research, Pasadena, CA, United States), AB(University of Toronto, Toronto, Canada; 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), AE(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States) |
| Journal: | Icarus, Volume 317, p. 649-668. |
| Publication Date: | Jan 2019 |
| Origin: | Elsevier BV |
| Abstract Copyright: | (c) 2019 Elsevier Science B.V. All rights reserved. |
| 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. <P />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. <P />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: | Replication of the historic record of Martian global dust storm occurrence in an atmospheric general circulation model |
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| 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: | Mars Science Laboratory Observations of the 2018/Mars Year 34 Global Dust Storm |
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| Authors: | Guzewich, Scott D.; Lemmon, M.; Smith, C. L.; Martínez, G.; de Vicente-Retortillo, Á.; Newman, C. E.; Baker, M.; Campbell, C.; Cooper, B.; Gómez-Elvira, J.; Harri, A.-M.; Hassler, D.; Martin-Torres, F. J.; McConnochie, T.; Moores, J. E.; Kahanpää, H.; Khayat, A.; Richardson, M. I.; Smith, M. D.; Sullivan, R.; de la Torre Juarez, M.; Vasavada, A. R.; Viúdez-Moreiras, D.; Zeitlin, C.; Zorzano Mier, Maria-Paz |
| Affiliation: | AA(NASA Goddard Spaceflight Center, Greenbelt, MD USA), AB(Space Science Institute, College Station, TX USA), AC(Department of Earth and Space Science and Engineering, York University, Toronto, Ontario Canada), AD(College of Engineering, University of Michigan, Ann Arbor, MI USA), AE(College of Engineering, University of Michigan, Ann Arbor, MI USA), AF(Aeolis Research, Pasadena, CA USA), AG(Department of Earth and Planetary Science, The Johns Hopkins University, Baltimore, MD USA), AH(Department of Earth and Space Science and Engineering, York University, Toronto, Ontario Canada), AI(Department of Earth and Space Science and Engineering, York University, Toronto, Ontario Canada), AJ(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AK(Finnish Meteorological Institute, Helsinki, Finland), AL(Southwest Research Institute, Boulder, CO USA), AM(Atmospheric Science Group, 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), Armilla, Granada, Spain), AN(Department of Astronomy, University of Maryland, College Park, MD USA), AO(Department of Earth and Space Science and Engineering, York University, Toronto, Ontario Canada), AP(Finnish Meteorological Institute, Helsinki, Finland; School of Electrical Engineering, Aalto University, Espoo, Finland), AQ(NASA Goddard Spaceflight Center, Greenbelt, MD USA; CRESST II and Department of Astronomy, University of Maryland, College Park, MD USA), AR(Aeolis Research, Pasadena, CA USA), AS(NASA Goddard Spaceflight Center, Greenbelt, MD USA), AT(Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY USA), AU(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AV(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AW(Centro de Astrobiología (INTA-CSIC), Madrid, Spain), AX(Leidos, Houston, TX USA), AY(Centro de Astrobiología (INTA-CSIC), Madrid, Spain; Atmospheric Science Group, Division of Space Technology, Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology, Luleå, Sweden) |
| Journal: | Geophysical Research Letters, Volume 46, Issue 1, pp. 71-79. |
| Publication Date: | Jan 2019 |
| Origin: | American Geophysical Union (AGU) |
| Keywords: | Mars, Curiosity, Mars Science Laboratory, dust storm |
| Abstract Copyright: | ©2019. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2018GL080839 |
| Bibliographic Code: | 2019GeoRL..46...71G |
| Abstract: | Mars Science Laboratory Curiosity rover observations of the 2018/Mars year 34 global/planet-encircling dust storm represent the first in situ measurements of a global dust storm with dedicated meteorological sensors since the Viking Landers. The Mars Science Laboratory team planned and executed a science campaign lasting approximately 100 Martian sols to study the storm involving an enhanced cadence of environmental monitoring using the rover's meteorological sensors, cameras, and spectrometers. Mast Camera 880-nm optical depth reached 8.5, and Rover Environmental Monitoring Station measurements indicated a 97% reduction in incident total ultraviolet solar radiation at the surface, 30K reduction in diurnal range of air temperature, and an increase in the semidiurnal pressure tide amplitude to 40 Pa. No active dust-lifting sites were detected within Gale Crater, and global and local atmospheric dynamics were drastically altered during the storm. This work presents an overview of the mission's storm observations and initial results. |
2018
| Title: | Seasonal Deposition and Lifting of Dust on Mars as Observed by the Curiosity Rover |
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| Authors: | Vicente-Retortillo, Á.; Martínez, G. M.; Renno, N.; Newman, C. E.; Ordonez-Etxeberria, I.; Lemmon, M. T.; Richardson, M. I.; Hueso, R.; Sánchez-Lavega, A. |
| Affiliation: | AA(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), AC(Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, USA), AD(Aeolis Research, Pasadena, CA, USA), AE(Departamento de Física Aplicada I, Universidad del País Vasco, Bilbao, Spain), AF(Space Science Institute, College Station, TX, USA), AG(Aeolis Research, Pasadena, CA, USA), AH(Departamento de Física Aplicada I, Universidad del País Vasco, Bilbao, Spain), AI(Departamento de Física Aplicada I, Universidad del País Vasco, Bilbao, Spain) |
| Journal: | Scientific Reports, Volume 8, id. 17576. |
| Publication Date: | Dec 2018 |
| Origin: | Springer Science and Business Media LLC |
| DOI: | https://doi.org/10.1038/s41598-018-35946-8 |
| Bibliographic Code: | 2018NatSR...817576V |
| Abstract: | In situ measurements by the Curiosity rover provide a unique opportunity for studying the effects of dust on assets placed at the surface of Mars. Here we use in situ measurements of solar UV radiation to quantify the seasonal and interannual variability of dust accumulation on the sensor on the rover deck. We show that the amount of dust accumulated on the sensor follows a seasonal cycle, with net dust removal during the perihelion season until L<SUB>s</SUB> 300°, and net dust deposition until the end of the aphelion season (L<SUB>s</SUB> 300°-180°). We use independent in situ measurements of atmospheric opacity and pressure perturbations in combination with numerical modeling, showing that daytime convective vortices and nighttime winds are likely responsible for the seasonal dust cleaning, with the role of nighttime wind being more important in Martian Year (MY) 32 than in MY 33 and that of daytime convective vortices being more important in MY 33 than in MY 32. The fact that the UV sensor is cleaner in MY 33 than in MY 32 indicates that natural cleaning events make solar energy an excellent candidate to power extended (multiannual) Mars missions at similar latitudes as the Curiosity rover. |
| 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 |
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| Authors: | Richardson, Mark I.; Newman, Claire E. |
| Affiliation: | AA(Aeolis Research, Pasadena, CA, USA), AB(Aeolis Research, Pasadena, CA, USA) |
| Journal: | Planetary and Space Science, Volume 164, p. 132-157. |
| Publication Date: | Dec 2018 |
| Origin: | Elsevier BV |
| 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: | Complex bedding geometry in the upper portion of Aeolis Mons, Gale crater, Mars |
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| Authors: | Anderson, Ryan B.; Edgar, Lauren A.; Rubin, David M.; Lewis, Kevin W.; Newman, Claire |
| Affiliation: | AA(USGS Astrogeology Science Center, 2255 N. Gemini Dr., Flagstaff, AZ 86001, United States), AB(USGS Astrogeology Science Center, 2255 N. Gemini Dr., Flagstaff, AZ 86001, United States), AC(University of California Santa Cruz, Earth and Planetary Sciences, 1156 High Street, Santa Cruz, CA 95064, United States), AD(Johns Hopkins University, Earth and Planetary Sciences, 3400 N. Charles St., Baltimore, MD 21218, United States), AE(Aeolis Research, 600 N. Rosemead Blvd., Suite 205, Pasadena, CA 91107, United States) |
| Journal: | Icarus, Volume 314, p. 246-264. |
| Publication Date: | Nov 2018 |
| Origin: | Elsevier BV |
| Abstract Copyright: | (c) 2018 Elsevier Science B.V. All rights reserved. |
| DOI: | https://doi.org/10.1016/j.icarus.2018.06.009 |
| Bibliographic Code: | 2018Icar..314..246A |
| Abstract: | The Upper formation of Aeolis Mons in Gale crater exhibits curvilinear bedding patterns on the surfaces of several erosional benches that have been interpreted as cross-bedding. We use High Resolution Imaging Science Experiment (HiRISE) stereo topography to test this hypothesis by measuring the bedding geometry within these benches. The bedding geometry is consistent with aeolian cross-beds: measured dips rarely exceed the angle of repose, and the distribution of dip azimuths is non-random, allowing dune morphology and paleo-transport directions to be inferred using computer models of bedforms. The inferred dune type and transport direction vary between the benches of the Upper formation, indicating that the benches are separated by sufficient time for the wind regime to change. The paleo-wind directions derived from bedding geometry measurements differ from modern wind modeling results, suggesting that the conditions during deposition of the Upper formation were unlike modern conditions. The concentric bedding patterns in some locations indicate that the rate of deposition approached the rate of bedform migration. The evidence for lithified hundred-meter-scale dunes in the Upper formation of Aeolis Mons indicates that the area was a sediment sink at the time of formation, and any hypothesis for the formation of Aeolis Mons must be compatible with these results. We present one possible sequence of events for the formation of Aeolis Mons. |
| Title: | The Bagnold Dunes in Southern Summer: Active Sediment Transport on Mars Observed by the Curiosity Rover |
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| Authors: | Baker, Mariah M.; Lapotre, Mathieu G. A.; Minitti, Michelle E.; Newman, Claire E.; Sullivan, Robert; Weitz, Catherine M.; Rubin, David M.; Vasavada, Ashwin R.; Bridges, Nathan T.; Lewis, Kevin W. |
| Affiliation: | AA(Morton K. Blaustein Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD USA), AB(Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA USA), AC(School of Earth and Space Exploration, Arizona State University, Tempe, AZ USA), AD(Aeolis Research, Pasadena, CA USA), AE(Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY USA), AF(Planetary Science Institute, Tucson, AZ USA), AG(Department of Earth & Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA USA), AH(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA), AI(Deceased 26 April 2017), AJ(Morton K. Blaustein Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD USA) |
| Journal: | Geophysical Research Letters, Volume 45, Issue 17, pp. 8853-8863. |
| Publication Date: | Sep 2018 |
| Origin: | American Geophysical Union (AGU) |
| Abstract Copyright: | ©2018. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1029/2018GL079040 |
| Bibliographic Code: | 2018GeoRL..45.8853B |
| Abstract: | Orbiter-based observations have demonstrated that active aeolian environments are ubiquitous across Mars. Here we examine one such environment, the Bagnold Dune Field in Gale crater, with repeat imaging campaigns conducted from Curiosity during southern summer. Images reveal widespread migration of aeolian impact ripples (up to 2.8 cm/sol), which is in stark contrast to the inactivity of similar bedforms during southern winter. The winds responsible for steady southwestward migration of ripples are consistent with predictions of regional-scale flows that enter the crater from the north and interact with the topography of Mount Sharp but are not fully representative of all dune-forming winds. Inferred friction speeds of 1.5 m/s needed to explain mobilization of bedforms are likely not being achieved, and thus, a majority of sediment transport may be taking place at subthreshold conditions. This hypothesis is further supported by sand flux estimates that suggest a low saltation flux environment within the dune field. |
| Title: | The sensitivity of solsticial pauses to atmospheric ice and dust in the MarsWRF General Circulation Model |
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| Authors: | Lee, Christopher; Richardson, Mark I.; Newman, Claire E.; Mischna, Michael A. |
| Affiliation: | AA(Department of Physics, University of Toronto, St. George, Toronto, Ontario, M5S 1A7, Canada; Aeolis Research, Pasadena, CA, United States), AB(Aeolis Research, Pasadena, CA, United States), AC(Aeolis Research, Pasadena, CA, United States), AD(Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States) |
| Journal: | Icarus, Volume 311, p. 23-34. |
| Publication Date: | Sep 2018 |
| Origin: | Elsevier BV |
| Keywords: | Mars, Solsticial pause, Transient waves, Dust storms, Ice clouds |
| Abstract Copyright: | (c) 2018 Elsevier Inc. |
| 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. Previous 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 variability. 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 processes, 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 accurately 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 calculations 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 instability 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: | Coarse Sediment Transport in the Modern Martian Environment |
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| Authors: | Baker, M. M.; Newman, C. E.; Lapotre, M. G. A.; Sullivan, R.; Bridges, N. T.; Lewis, K. W. |
| Affiliation: | AA(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 Earth and Planetary Sciences, Harvard University, Cambridge, MA USA), AD(Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY USA), AE(Applied Physics Laboratory, The Johns Hopkins University, Laurel, MD USA; Deceased April 26, 2017,), AF(Morton K. Blaustein Department of Earth and Planetary Sciences, The Johns Hopkins University, Baltimore, MD USA) |
| Journal: | Journal of Geophysical Research: Planets, Volume 123, Issue 6, pp. 1380-1394. |
| Publication Date: | Jun 2018 |
| Origin: | Wiley |
| Keywords: | aeolian transport, atmosphere-surface interactions, Curiosity rover imaging campaigns |
| Abstract Copyright: | ©2018. American Geophysical Union. All Rights Reserved. |
| DOI: | https://doi.org/10.1002/2017JE005513 |
| Bibliographic Code: | 2018JGRE..123.1380B |
| Abstract: | The occurrence of regional and global dust storms, observations of migrating ripples and dunes, and the recognition of aeolian sandstone outcrops demonstrate that aeolian processes have been and continue to be a significant agent of surface modification on Mars. However, the mechanisms of aeolian transport within Mars' low atmospheric pressure surface environment are still not fully understood. This work presents a synthesis of change detection observations conducted with the Mars Science Laboratory Curiosity rover in Gale crater over three Martian years. Sediment mobility during this period was highly variable, consistent with previous orbiter-based observations showing strong seasonal variability, with strongest winds expected during southern summer. Wind activity inferred at each change detection site helps test the accuracy of atmospheric models, as well as constrain the intensity of current atmosphere-surface interactions and the physics of sand transport in the tenuous Martian atmosphere. Results indicate an apparent discrepancy between predicted wind speeds and the wind strengths required by classical incipient-motion models to explain observed sediment motion. Observed mobilization of perched and/or isolated very coarse sand grains and fine pebbles (i.e., grain sizes 1 mm ≤d≤3 mm) likely requires an alternate explanation, such as very strong but infrequent wind gusts, drag-induced rolling, or impact-driven creep caused by smaller saltating particles. |
| Title: | The cascade from local to global dust storms on Mars: Temporal and spatial thresholds on thermal and dynamical feedback |
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| Authors: | Toigo, Anthony D.; Richardson, Mark I.; Wang, Huiqun; Guzewich, Scott D.; Newman, Claire E. |
| Affiliation: | AA(Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United States), AB(Aeolis Research, Pasadena, CA, United States), AC(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, United States), AD(NASA Goddard Space Flight Center, Greenbelt, MD, United States), AE(Aeolis Research, Pasadena, CA, United States) |
| Journal: | Icarus, Volume 302, p. 514-536. |
| Publication Date: | Mar 2018 |
| Origin: | Elsevier BV |
| Keywords: | Mars, Atmosphere, Atmospheres, Dynamics, Meteorology |
| Abstract Copyright: | (c) 2018 Elsevier Inc. |
| 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 atmosphere 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<SUP>5</SUP> km<SUP>2</SUP>) and durations (1-10 sols) of local dust storms, modification of the atmosphere is less than the typical variability of the unperturbed (storm-free) state. Even if imposed on regional storm length scales (order 10<SUP>6</SUP> km<SUP>2</SUP>), 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 significant 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. |