Rain Production in Convective Clouds as Simulated in an Axisymmetric Model with Detailed Microphysics. Part II: Effects of Varying Drops and Ice Initiation

Abstract

Abstract This paper presents an evaluation of the relative importance of the warm versus cold processes in convective clouds and their relative contribution to the development of rain. For this purpose, an axisymmetrical model of a cold convective cloud with detailed microphysics is used. Five different types of clouds having characteristics from maritime to extreme continental are simulated. Identical initial conditions are used, leading to the formation of convective clouds of medium depth, with relatively strong updrafts. For these specific conditions, the effects of the different microphysical processes on the production of rain are tested by varying the cloud condensation nuclei (CCN) spectra and the spectra of the nucleated drops. The role of ice crystal concentrations and drop freezing is also reviewed. The simulations showed that maritime clouds are efficient rain producers. In these clouds, large graupel mass contents develop by the freezing of large drops through their interaction with ice cryst...