MRO-MCS observed polar warming and clouds during 2018 Martian global dust storm

Abstract

This study focused on the impact of most recent global dust storm (GDS) of 2018 over the north polar region of Mars using the observations from Mars Climate Sounder (MCS) onboard Mars Reconnaissance Orbiter. The MCS column integrated dust opacity shows the peak of the dust storm during LS~195-210° (LS is the solar longitude), which is also visible over the polar region. The vertically integrated polar warming index (PWI) in the NH shows a decline during the active storm phase of GDS 2018, indicates more dust radiative heating over low-mid latitudes. Also, PWI variation suggests a delayed response (~ 10°Ls) of the polar atmosphere to the active dust lifting over northern low to southern mid-latitudes. No significant change in the cloud vertical depth is observed on the poleward side of the north polar hood. These observations indicate only an indirect (not by direct radiative forcing and associated heating) impact of global dust loading in the north polar atmosphere during the decaying phase of the 2018 GDS.