Development of a Stochastic Cloud-Radiation Parameterization

A parameterization of the stochastic approach to modeling cloud-radiation interactions is being developed using archived data from the Atmospheric Radiation Measurement (ARM) Program's Clouds And Radiation Testbed sites. Initially, long time-series data from the ARM Southern Great Plains site will be used to characterize the cloud base height, cloud top height, cloud size, cloud spacing, and cloud optical properties during the year 2000. These observations will be analyzed to be input to a shortwave stochastic radiative transfer model. Subsequent analysis will include data from the Tropical Western Pacific site and the North Slopes of Alaska site. The output domain-averaged radiation fields will be evaluated using independent observations. One benefit of the stochastic approach is the ability to calculate more realistic heating rates. The impact of these heating rates on model dynamics will be investigated using a single-column model.