Resolving Convection of CO 2 Ice Clouds in the Martian Polar Nights

• Published in: Geophysical Research Letters
• Main Authors: Caillé, Vincent, Spiga, Aymeric, Määttänen, Anni, Falletti, Lola, Mathé, Christophe
• Other Authors: Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL), PLANETO - LATMOS, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2024
• Subjects: [SDU]Sciences of the Universe [physics]; polar night
• Online Access: https://insu.hal.science/insu-04620042; https://insu.hal.science/insu-04620042/document; https://insu.hal.science/insu-04620042/file/GRL-%202024%20-%20Caille%CC%81%20-%20Resolving%20.pdf; https://doi.org/10.1029/2023gl106923

International audience Martian CO2 ice clouds are intriguing features, representing a rare occurrence of atmosphericcondensation of a major component. These clouds play a crucial role due to their radiative properties,interactions with surface, and coupling with microphysical cycles of aerosols. Observations have been limited,prompting modeling studies to understand their formation and dynamics. Here, we present the first high‐resolution 3D simulations of CO2 ice clouds using a Large‐Eddy Simulation (LES) model incorporating CO2microphysics. We investigate cloud formation in idealized temperature perturbations in the polar night. Areference simulation with a 2K perturbation demonstrates that the formed CO2 ice cloud possesses aconvective potential, leading to its ascent in the troposphere. We determine the timescales and orders ofmagnitude of various phenomena involved in the lifecycle of a CO2 ice cloud. Sensitivity tests show thatconvection can be inhibited or intensified by the thermodynamic and microphysical conditions of the simulatedenvironment.