Simulating moist convection with a quasi-elastic sigma coordinate model

Abstract

Cloud Resolving Models (CRMs) employ microphysics parameterisations which are grouped into bin and bulk approaches. Bulk Microphysics Parameterisation (BMP) schemes specify a functional form for the particle distribution and predict one or more characteristics of a particle category such as the mixing ratio and concentration. In this study two BMPs have been introduced to a dynamical core developed in South Africa and the updated model was used to study the effect of resolution and microphysics set-up on isolated thunderstorms. The results show that thunderstorm cell redevelopment depends on the microphysics set-up. Lower resolution leads to smaller updrafts and downdrafts which in turn affects the amount of the simulated hydrometeors.