Minimum Mars Climate Sounder Retrieval Altitudes Reveal Cloud Altitudes at Aphelion and Stranded High-altitude Dust Following the MY34 Global Dust Storm on Mars

Abstract

Abstract The Mars Climate Sounder (MCS) has been observing Mars’ atmosphere since the Mars Reconnaissance Orbiter’s arrival in 2006. While MCS can theoretically observe down to the surface, in practice the presence of aerosols such as dust and water ice can cut off retrievals at altitudes tens of kilometers above the surface. We examine the minimum cut-off altitudes of MCS temperature retrievals over the course of MCS's mission for the area around Gale Crater. We see a preference for cut-off altitudes above 20 km in the cloudy season and greater variation in preference in the dusty season. These cut-off altitudes can be used to infer cloud altitudes and to track the decay of significant dust storms as well as seeing the effects of stranded dust in the MY 34 global dust storm.