Geographic Patterns of Fine-scale TRMM PR Rain Climatology and Retrieval Uncertainties

A number of rain samples observed by the spaceborne precipitation radar, TRMM PR, have provided data on the steep spatial variability of precipitation climatology and retrieval uncertainties that exist at different surfaces. As such, this study focuses on the evaluation of long-term mean precipitation extremes and local biases found within global precipitation datasets. First, local precipitation concentrations around coastal and mountainous regions are presented on the basis of 0.1- and 0.01-degree scale TRMM PR datasets. It was accordingly determined that afternoon rainfall maxima of small-scale precipitation systems are significant over tropical and subtropical coastal areas. Moreover, sharp geographic contrasts on the kilometer scale consistently appeared in tropical mountainous areas such as near/around the highest mountain in Oceania (Puncak Jaya in New Guinea). Second, differences among precipitation datasets based on passive radiometer and gauge observations are investigated with a focus on localized precipitation systems observed via a spaceborne radar. Finally, systematic biases of TRMM PR and GPM DPR datasets on main-lobe clutter filtering and their impact on climatological spatial representations are discussed. It was determined that corrections increase more than 10% of aggregate rainfall amounts over areas at the edge of satellite domains as well as specific orographic regions where clutter-free bottom levels are high.