Strong Anthropogenic Cloud Perturbations Can Persist for Multiple Days

Abstract

AbstractUsing geostationary satellite data, we show that strong cloud perturbations downwind of isolated continental anthropogenic aerosol sources can live for multiple days, and 7% of tracks live longer than 48 hr. The median lifetime for polluted cloud tracks in Eastern Europe studied using Spinning Enhanced Visible and Infrared Imager data is 18 hr but shows a strongly skewed distribution toward longer lifetimes. This suggests that ship‐track‐like cloud perturbations help infer causal relationships between aerosols and clouds. Strong anthropogenic cloud perturbations are usually visible until favorable liquid‐water low‐level clouds exist. Only in 12% of cases do liquid‐phase stratiform clouds persist, but tracks disappear. Longer‐lived tracks occur in anticyclonic conditions, and in case of statically very stable lower troposphere and low relative humidity above clouds.