Retrieval algorithms for estimating the vertical profiles of latent heat release: Their applications for TRMM

Abstract

The latent heat release is a consequence of phase change (vapor, liquid and solid) of water. An algorithm has been developed (Tao et al, 1990) to estimate the latent heating of cloud systems as a function of their vertical hydrometeor profiles (termed a hydrometeor/heating algorithm). The derivation as well as the validation of the algorithm was based on results of a non-hydrostatic cloud model. The improvement of the hydrometeor/heating algorithm and its performance when tested on cloud systems which occurred in various geographic locations are discussed in this paper. Also the application of the hydrometeor/heating algorithm to incorporate surface precipitation as well as vertical hydrometeor profiles derived from multi-channel passive microwave rain retrieval algorithms is presented. The hydrometeor/heating algorithm requires information associated with the vertical profiles of various hydrometeors (ice and water). Although these vertical hydrometeor profiles can be derived from the TRMM radar directly and microwave sensors indirectly, the heating/hydrometeor algorithm needs to differentiate between large and small water/ice particles. Thus, a second retrieval algorithm (termed a convective-stratiform heating algorithm) has been developed. The inputs for this new algorithm are surface rainfall rates and amount of stratiform rain. This convective-stratiform heating algorithm also needs a look-up table which consists of latent heating profiles associated with various types of cloud systems at different geographic locations. The procedure as well as the performace of the convective-stratiform heating algorithm is discussed in this paper.