Thermal And Microphysical Effects Of Ice Clouds On Torrential Rainfall Over Northern China

Abstract

Ice clouds are an important part of precipitation systems and their thermal and microphysical and radiative effects may impact rainfall. In this study, the thermal and microphysical effects of ice clouds on rainfall are investigated through the diagnostic analysis of rainfall and heat budgets of a torrential rainfall simulation in north China during July 2013. During daytime, the inclusion of the thermal effects of ice clouds weakens rainfall mainly by the inclusion of latent-heat effects of ice clouds, which suppresses instability and upward motions. During nighttime, the inclusion of the thermal effects of ice clouds increases rainfall mainly by the inclusion of radiative effects of ice clouds, which enhances radiative cooling in the upper troposphere and suppresses radiative cooling in the lower troposphere and thus increases instability and upward motions. The inclusion of microphysical effects of ice clouds increases rainfall directly by the inclusion of deposition and indirectly by the increasing condensation.