Biomass Burning Aerosol and Open Cell Formation

Pockets of open cells are regions of broken, precipitating stratocumulus clouds embedded into an overcast stratocumulus cloud deck with little or no drizzle. Owing to their low cloud fraction, pockets of open cells have a reduced cloud shortwave radiative effect compared to the surrounding stratocumulus deck. Previous work has identified meteorological and microphysical factors that contribute to the formation of the open cells from the overcast stratocumulus cloud state. This work uses cloud-system resolving simulations to investigate the role and significance of biomass burning aerosol overlying a South-East Atlantic stratocumulus cloud deck in the formation of open cells observed during the Cloud Aerosol Radiation Interactions and Forcing field campaign (CLARIFY).