Interannual Variability of Dust Storms between Mars Years 24 and 36 and analysis of dust vertical distribution of the MY 34 late-storm.

Abstract

Dust storms on Mars cause variations in atmospheric temperatures and dynamics due to direct solar heating and its dynamic response. These effects are most intense during the dust storm season (Ls 180º - 360º), when most global and regional storms occur and when the suspended dust reaches higher altitudes in the atmosphere. The thermal impact of these events affects the regional and global circulation of Mars. Thanks to measurements taken by the Thermal Emission Spectrometer (TES) onboard the Mars Global Surveyor (MGS) and the Mars Climate Sounder (MCS) onboard the Mars Recoinnasance Orbiter (MRO) it is possible to study the spatial and temporal variability of these storms over the last 12 Martian years (Martín-Rubio et al., 2024). Although each storm must be considered independently, it is possible to observe how the storms recur seasonally following specific patterns that allow them to be grouped according to their time of occurrence and evolution, with the recurrence patterns named as type A, B and C (Kass et al., 2016). Late northern winter large regional storms (C-type storms) show the highest variability; it appears that the occurrence of Global Dust Storms does not have a simple direct effect in the intensity of the subsequent C-type storm. We analyze recent intense type C storms (MY 34, 35 and 36, with particular focus on MY 34, when a Global Dust Storm occurred), studying the vertical, latitudinal and longitudinal dust distribution that occurred between solar longitudes Ls = 318° - 335°. This study is important to better understand the interannual variability of regional dust storms on Mars, as well as dust transport during late northern winter regional storms.