Radar-Derived Estimates of Latent Heating in the Subtropics

Abstract

Atmospheric warming from cloud heating has a major affect on worldwide atmospheric circulations and climate. Studies have shown that the dominant source for cloud heating is the phase change of water. The location and magnitude of cloud heating has a substantial impact on atmospheric circulations. Therefore, identifying the location of phase changes provides information necessary for accurate modeling of atmospheric circulations and climate. Radar reflectivity is a signature predominantly produced from rain formed from condensation, the primary process that produces heating. Through the application of principal component analysis on a nonhydrostatic cloud model, heating, and derived reflectivity data, a technique to illustrate a future heating algorithm capable of estimating cloud heating from reflectivity data is examined. Formative, intensifying, and mature stages of a Convection and Precipitation Electrification Experiment squall-type convective system were used to demonstrate these results. The accuracy of the technique?s estimates for the mean convective and stratiform profiles to within 1.0 K h?1 on average throughout the vertical column shows the merit of this statistical technique. The use of this type of technique in conjunction with the network of NEXRAD and spaceborne radars could provide valuable data for applications ranging from cumulus parameterization to 4D data assimilation and model initialization.