Stabilization of tenuous atmospheres by atmospheric dust in the HZ of M-dwarf Stars

The most significant challenge to terrestrial planet habitability in the habitable zone of M stars is the maintenance of a planetary atmosphere that is stable against nightside atmospheric collapse. Here, we investigate the stabilization potential of atmospheric dust in CO2 atmospheres of varying densities. Using the exoplanet configuration of the new FV3-based Mars global climate model, we find that tenuous atmospheres with surface pressures less than 10mbar can be maintained with reasonable visible global dust opacities between 0.5 and 5. We investigate the primary mechanism by which dust warms the nightside and analyze changes to the planetary dynamics and day to night heat transport.