A Two Martian Years Survey of Water Ice Clouds on Mars With ACS Onboard TGO

The middle infrared (MIR) channel of the Atmospheric Chemistry Suite (ACS) instrument onboard ExoMars Trace Gas Orbiter (TGO) ESA-Roscosmos mission has performed Solar occultation measurements Martian atmosphere in 2.3-4.2 $\mu$m spectral range since March 2018, which now covers two Years (MY). We use methodology previously developed for study MY 34 Global Dust Storm (GDS) (Stcherbinine et al., 2020) to monitor properties (effective radii, extinction, altitude) water ice clouds over first years covered by ACS-MIR. observations encompass period $L_s$ = 163{\deg} 181{\deg} 36. determine that typical altitude varies 20 40 km between summer and winter, with a maximum extension up 80 during midlatitudes. Similarly, we also note limited temporal range, polar regions compare acquired GDS from same 35, using latter as reference characterize effects this on clouds' properties. In addition, our retrievals predictions Mars Planetary Climate Model (PCM), shows reasonable agreement overall clouds, although model usually predicts lower altitudes top clouds.