REEXAMINATION OF THE STATE OF THE ART OF CLOUD MODELING SHOWS REAL IMPROVEMENTS

The case of a synoptically driven cirrus cloud field occurred on 1 April 2010 over the Atmospheric Radiation Measurement Program (ARM) Southern Great Plains (SGP) site in Oklahoma.\n The objectives of this case are to investigate the effects of diabatic cooling on the precipitation phase transition and the mesoscale flow in complex terrain and the sensitivity to details in the parameterization of melting snow. General conclusions from the workshop are as follows: 1) For most cloud modeling applications, simple microphysical parameterizations with fixed CCN are being replaced with more detailed schemes, and there is a clear trend toward more sophisticated and interactive cloud microphysical schemes with the capability of aerosol processing. 2) Advances in the representation of ice properties, ice initiation, and crystal growth in cloud microphysical parameterizations have led to improved simulations of the properties of mixed-phase and cold clouds, but uncertainties remain, especially with respect to the prediction of ice number concentrations and the effects of aerosol particles on ice formation. 3) Regional climate models are approaching the cloud-permitting and cloud-resolving scale; this will open the way for new regional climate change applications and links to hydrology.