#PNNL-led international study finds ultrafine #aerosols have outsize impact on storm clouds, precipitation
Deep convective cloud (DCC) systems in the tropics produce copious precipitation and drive the global-scale circulation. Precipitation, latent heating, and cloud radiative forcing associated with DCCs are strongly modulated by cloud microphysical processes. These processes in tropical DCCs are initiated from droplet nucleation (which is determined by vapor supersaturation in updrafts and aerosol properties such as composition and size distribution. Aerosol impacts on cloud processes via this pathway are known as aerosol indirect effects, referred to as aerosol-cloud interaction in the most recent Intergovernmental Panel on Climate Change report. Aerosol impacts are a key uncertainty in understanding the current and future climate as well as extreme weather. DCCs have complicated dynamics and microphysics; therefore, aerosol impacts on them are extremely complex and hard to...