Recent Ice Ages on Mars: The role of radiatively active clouds and cloud microphysics - Archive ouverte HAL Access content directly
Journal Articles Geophysical Research Letters Year : 2014

Recent Ice Ages on Mars: The role of radiatively active clouds and cloud microphysics

Abstract

Global Climate Models (GCMs) have been successfully employed to explain the origin of many glacial deposits on Mars. However, the Latitude Dependent Mantle (LDM), a dust-ice mantling deposit that is thought to represent a recent "Ice Age", remains poorly explained by GCMs. We reexamine this question by considering the effect of radiatively active water-ice clouds (RACs) and cloud microphysics. We find that when obliquity is set to 35°, as often occurred in the past 2 million years, warming of the atmosphere and polar caps by clouds modifies the water cycle and leads to the formation of a several centimeter-thick ice mantle poleward of 30° in each hemisphere during winter. This mantle can be preserved over the summer if increased atmospheric dust content obscures the surface and provides dust nuclei to low-altitude clouds. We outline a scenario for its deposition and preservation that compares favorably with the characteristics of the LDM.
Fichier principal
Vignette du fichier
Madeleine_2014_Recent_Ice_Ages_on.pdf (1.09 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive
Loading...

Dates and versions

hal-01023522 , version 1 (11-04-2016)

Identifiers

Cite

Jean-Baptiste Madeleine, James W. Head, François Forget, Thomas Navarro, Ehouarn Millour, et al.. Recent Ice Ages on Mars: The role of radiatively active clouds and cloud microphysics. Geophysical Research Letters, 2014, 41 (14), pp.4873-4879. ⟨10.1002/2014GL059861⟩. ⟨hal-01023522⟩
526 View
90 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More