Gravity Wave-induced High-altitude CO2 Ice Clouds in Mars' Atmosphere

Abstract:

First general circulation model simulations that quantify and reproduce patches of cold air required for CO₂ condensation and ice cloud formation in Mars' atmosphere are presented. Results suggest that these ice clouds are generated by lower atmospheric small-scale gravity waves (GWs) accounted for in the model with the interactively implemented spectral GW parameterization of Yiğit et al. (2008). Distributions of GW-induced temperature fluctuations and occurrences of supersaturation
conditions are in a good qualitative agreement with observations of high-altitude CO₂ ice clouds. Our study confirms the key role of subgrid-scale GWs in facilitating high-altitude CO₂ cloud formation and predicts clouds at altitudes higher than have been observed to date.