Gravity waves and high-altitude CO2ice cloud formation in the Martian atmosphere

Abstract

We present the first general circulation model simulations that quantify and reproduce patches of extremely cold air required for CO2condensation and cloud formation in the Martian mesosphere. They are created by subgrid-scale gravity waves (GWs) accounted for in the model with the interactively implemented spectral parameterization. Distributions of GW-induced temperature fluctuations and occurrences of supersaturation conditions are in a good agreement with observations of high-altitude CO2ice clouds. Our study confirms the key role of GWs in facilitating CO2cloud formation, discusses their tidal modulation, and predicts clouds at altitudes higher than have been observed to date.