MARTIAN WATER ICE LATITUDE DEPENDENT MANTLE PREDICTED BY IMPROVED CLIMATE MODEL

The physics of the Mars PCM (previously LMD Mars GCM) has been improved : cloud nucleation now has a temperature-dependent scheme, latent heat of ground ice sublimation is computed and overall physical resolution is enhanced. Under these conditions, we find that retroactions of albedo and thermal inertia allow perennial deposition of ice outside the polar regions when increasing the obliquity of Mars from its present day value of 25° toward 35°, with accumulation rates compatibles with the formation of a "Latitude-Dependent Mantle" during the last high obliquity excursion.