Climatology and Interannual Variability of Quasi-Global Intense Precipitation Using Satellite Observations.

Climatology and variations of recent mean and intense precipitation over a near global (50°S-50°N) domain on a monthly and annual time scale are analyzed. Data used to derive daily precipitation to examine the effects of spatial and temporal coverage of intense precipitation are the current Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) 3B42 Version 7 precipitation product, with high spatial and temporal resolution during 1998-2013. Intense precipitation is defined by several different parameters, such as a 95th percentile threshold of daily precipitation, a mean precipitation that exceeds that percentile or a fixed threshold of daily precipitation value (e.g., 25 and 50 mm day-1). All parameters are used to identify the main characteristics of spatial and temporal variation of intense precipitation. High correlations between examined parameters are observed, especially between climatological monthly mean precipitation and intense precipitation, both over tropical land and ocean. Among the various parameters examined, the one best characterizing intense rainfall is a fraction of daily precipitation ≥25 mm day-1, defined as a ratio between the intense precipitation above used threshold and mean precipitation. Regions that experience an increase in mean precipitation likely experience a similar increase in intense precipitation, especially during the El Niño-Southern Oscillation (ENSO) events. Improved knowledge of this intense precipitation regime and its strong connection to mean precipitation given by the fraction parameter can be used for monitoring of intense rainfall and its intensity on a global to regional scale.