How, when and where current mass flows in Martian gullies are driven by CO2 sublimation

Communications Earth & Environment, Journal Year: 2024, Volume and Issue: 5(1)

Published: March 13, 2024

Abstract Martian gullies resemble water-carved on Earth, yet their present-day activity cannot be explained by water-driven processes. The sublimation of CO 2 has been proposed as an alternative driver for sediment transport, but how this mechanism works remains unknown. Here we combine laboratory experiments -driven granular flows under atmospheric pressure with 1D climate simulation modelling to unravel how, where, and when can drive gully activity. Our work shows that ice, conditions fluidize creates morphologies similar those observed Mars. Furthermore, the modelled climatic topographic boundary process, align These results have implications influence water versus processes in formation interpretation landforms other planets, existence is no longer definitive proof flowing liquids.

Language: Английский

---

Modeling Slope Microclimates in the Mars Planetary Climate Model

Journal of Geophysical Research Planets, Journal Year: 2023, Volume and Issue: 128(10)

Published: Oct. 1, 2023

Abstract A large number of surface features (e.g., frost, gullies, slope streaks, recurring lineae) are observed on Martian slopes. Their activity is often associated with the specific microclimates these slopes, which have been mostly studied one‐dimensional radiative balance models to date. We develop here a parameterization simulate in 3D Global Climate Models. first demonstrate that any can be thermally represented by poleward or equatorward slope, is, daily average, minimum, and maximum temperatures depend North‐South component slope. Based this observation, we implement subgrid‐scale represent (radiative fluxes, volatile condensation, ignoring winds for now) Mars Planetary Model validate it through comparisons temperature measurements frost detections sloped terrains. With new model, show do not significant impact seasonal CO 2 H O cycles global scale. Furthermore, short‐scale slopes (i.e., less than ∼1 km length) significantly thermal state atmosphere. Ninety‐one percent active gullies found where our model predicts suggesting their related processes involving ice. However, low thicknesses (≤tens cm) predicted at mid‐latitudes rule out mechanisms amounts (∼meters) This opens way studies surface‐atmosphere interactions present past climates.

Language: Английский

---

Subsurface stratigraphy suggested by the layered ejecta craters in the Martian northern planitiae

Icarus, Journal Year: 2024, Volume and Issue: 416, P. 116100 - 116100

Published: April 25, 2024

Language: Английский

---

Observations of Water Frost on Mars With THEMIS: Application to the Presence of Brines and the Stability of (Sub)Surface Water Ice

Journal of Geophysical Research Planets, Journal Year: 2024, Volume and Issue: 129(10)

Published: Sept. 27, 2024

Abstract Characterizing the exchange of water between Martian atmosphere and (sub)surface is a major challenge for understanding mechanisms that regulate cycle. Here we present new data set ice detected on surface with Thermal Emission Imaging System (THEMIS). The detection based correlation bright blue‐white patterns in visible images temperature measured infrared too warm to be associated interpreted instead as ice. Using this method, detect down 21.4°S, 48.4°N, pole‐facing slopes at mid‐latitudes, any orientation poleward 45° latitude. Water observed THEMIS most likely seasonal rather than diurnal. Our consistent near‐infrared frost detections predictions by Mars Planetary Climate Model. average 170 K, maximum 243 lower melting point. Melting pure unlikely due cooling latent heat during its sublimation. However, show frosts are hot enough form brines if salts surface. vapor pressure surface, calculated from temperature, indicates dry early spring, recession cap. large amount released sublimation cannot stabilize subsurface mid‐latitudes.

Language: Английский

---

Evaluating Possible Glacial Modification in the Martian Tropics Near Gale Crater Using a New U-Shaped Valley Metric

Published: Jan. 1, 2024

Download This Paper Open PDF in Browser Add to My Library Share: Permalink Using these links will ensure access this page indefinitely Copy URL DOI

Language: Английский

---

Evaluating possible glacial modification in the Martian tropics near Gale crater using a new U-shaped valley metric

Geomorphology, Journal Year: 2024, Volume and Issue: unknown, P. 109454 - 109454

Published: Oct. 1, 2024

Language: Английский

---