Ensemble Spatial-Temporal Characteristics of Rainfall Diurnal Cycle from TRMM

Various recent studies from TRMM rainfall datasets indicate that rainfall diurnal variability is a global phenomenon with embedded diurnal phenomena far more complex than can be explained by general causal factors. The dominant early-morning ocean rainfall peak is often accompanied by a secondary afternoon peak while the dominant mid- to late-afternoon continental rainfall peak can be replaced or accompanied by a secondary morning peak. The lesson from TRMM is that there are a host of mechanisms at work in producing diurnal scale rainfall processes, no one of which can be used to explain the entire process, but instead involving a mixture of mechanisms whose individual components control regional and smaller scale diurnal modes working together to describe the ensemble or averaged global process.

This talk would focus on the ensemble spatial-temporal features of underlying variations based on 8 years TRMM precipitation datasets. Results will present the detailed components of the ensemble spatial-temporal diurnal rainfall cycle across the globe tropics. By analyzing the ensemble features of rainfall diurnal cycles for different rain categories at different time-space scales, we try to demonstrate impacts of spatial-temporal scales on diurnal variability of precipitation, and provide scientific explanations of multiple mechanisms working together in producing the ensemble characteristics of the global rainfall diurnal cycle.