Forecast Model Applications of Satellite-derived Cloud Parameters

Abstract

Abstract : Microphysical characteristics in maritime cloud have significant control on cloud layer evolution, electromagnetic propagation, cloud aerosol interactions, visibility, and aircraft flight hazards. While the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) model may not in the immediate future explicitly represent cloud microphysical parameters, the relationship of cloud structure to the predicted variables must be assessed, particularly when considering physical or radiative parameterizations. Electromagnetic signal propagation through the atmosphere is directly influenced by the size and composition of atmospheric particles. Cloud droplet size, particularly at cloud top in the marine atmospheric boundary layer (MABL), plays a role in the rate at which turbulent entrainment produces aerosol via evaporation or removes aerosol via collection by droplets. The droplet size distribution also controls the effectiveness of the stochastic collision coalescence process in producing drizzle or rain, thereby also impacting the evaporative source (or collection loss) of aerosol during drop sedimentation below cloud. These processes can be incorporated into combined aerosol cloud simulation models by explicit or parameterized treatments.