A simple one-dimensional model to estimate mesoscale atmospheric latent heating profiles from TRMM rain statistics

In this study, a model is developed to estimate mesoscale-resolution atmospheric latent heating (ALH) profiles. It utilizes rain statistics deduced from Tropical Rainfall Measuring Mission (TRMM) data, and cloud vertical velocity profiles and regional surface thermodynamic climatologies derived from other available data sources. From several rain events observed over tropical ocean and land, ALH profiles retrieved by this model in convective rain regions exhibit strong warming throughout most of the troposphere, while in stratiform rain regions they usually show slight cooling below the freezing level and significant warming above. The mesoscale-average, or total, ALH profiles reveal a dominant stratiform character.; Model sensitivity tests show that total ALH at a given tropospheric level varies by less than ±10% when convective and stratiform rain rates and fractional rain areas are perturbed individually by ±15%. This is also found when the non-uniform convective vertical velocity profiles are replaced by one that is uniform. Larger variability of the total ALH profiles arises when climatological ocean- and land-surface temperatures (water vapor mixing ratios) are independently perturbed by ±1.0 K (±5%) and ±5.0 K (±15%), respectively. At a given tropospheric level, such perturbations can cause a ±25% variation of total ALH over ocean, and a factor-of-two sensitivity over land. This sensitivity is reduced substantially if perturbations of surface thermodynamic variables do not change surface relative humidity, or are not extended throughout the entire model evaporation layer.; The ALH profiles retrieved in this study agree qualitatively with tropical total diabatic heating profiles deduced in earlier studies. Also, from January and July 1999 ALH-profile climatologies generated separately with TRMM Microwave Imager and Precipitation Radar rain statistics, it is shown that ALH profiles can be retrieved utilizing diverse satellite-derived rain products with convective and stratiform discrimination. Therefore, the ALH profile retrieval model developed in this study can be used to make regional estimates of total diabatic heating profiles during future satellite missions to quantify precipitation, and to assimilate these profiles into numerical weather forecast and climate models.