Single column simulations of COSMO for the GCSS RICO precipitating shallow cumulus case

Single-column model (SCM) simulations of the operational limited-area weather prediction COSMO model at the German Weather Service (Deutscher Wetterdienst, DWD) for the GCSS RICO precipitating cumulus case are presented. The simulations are based on prescribed surface conditions (sea surface temperature, surface pressure), initial profiles of horizontal wind components, temperature, and specific humidity. Large scale subsidence, temperature forcing due to advection and radiation, and horizontal moisture advection was included. The main focus was in the use of the SCM for evaluation of assumptions used in the cloud microphysics scheme (e.g,. cloud droplet number concentration) and in the moist turbulence scheme (e.g., subscale cloud coverage). The aim is to investigate the impact of these assumptions on the simulation results for development of improved formulations, which can be applied to the three-dimensional COSMO model.