Radiative effects of water clouds on rainfall responses to the large-scale forcing during pre-summer heavy rainfall over Southern China

Water clouds are an essential ingredient of precipitation systems and their radiative effects may significantly impact rainfall processes. This study investigates radiative effects of water clouds on rainfall using a two-dimensional cloud-resolving model simulation of a pre-summer heavy rainfall event over southern China from 3 to 8 June 2008, forced with large-scale data from NCEP/GDAS. During the onset phase, the exclusion of radiative effects of water clouds increased the mean rain rate through the mean hydrometeor change from loss to gain in the presence of radiative effects of ice clouds, whereas it increased the mean rain rate through the increases in the mean net condensation and mean hydrometeor loss in the absence of radiative effects of ice clouds. During the development phase, the removal of radiative effects of water clouds enhanced the mean rainfall through the mean hydrometeor change from gain to loss. During the mature phase, the elimination of radiative effects of water clouds weakened the mean rainfall through the decreased mean net condensation. The exclusion of radiative effects of ice clouds enhanced the decrease in the mean rainfall. During the decay phase, the removal of radiative effects of water clouds increased the mean rainfall through the enhanced net condensation.