Impact of vertical wind on aerosol-cloud interaction in water clouds observed over an Indian continental region

The vertical wind has a strong influence on cloud properties and aerosol-cloud interaction (ACI). The goal of this study is to investigate the impact of vertical wind (updraft and downdraft) at the cloud base altitude on aerosolcloud interaction using a combination of ground-based, in-situ, and reanalysis datasets over an Indian continental region. Case studies using vertical wind observations obtained from the Indian MST radar and collocated measurements support the hypothesis that during updraft at the cloud base altitude, enhancement in the ACI is found due to the increased flow of aerosol/CCN into the cloud, thereby causing new particle formation. However, detailed analysis using ERA5 reanalysis datasets supports the hypothesis that vertical motion can attenuate or amplify ACI depending on the type of mixing process. Thus, constraining vertical wind in the ACI studies is very important along with other meteorological and dynamical aspects.