Exploring Global Precipitation Extremes with CHIRPS v2.0 (Invited Presentation)

The Climate Hazards InfraRed Precipitation with Stations (CHIRPS) is a powerful high resolution precipitation dataset useful for identifying changes in climate since 1981. In this presentation we use CHIRPS to examine global and regional precipitation extremes, with emphasis on (1) changes to spatial distribution and intensity of drier/wetter than normal conditions and (2) cases of recent extremes. Getting insight on changes in the extent and severity of droughts is an essential input to FEWS NET’s continued monitoring of food security around the world. This analysis shares results that are relevant to impact assessments of large scale climate variability and climate trends.

Annual total precipitation for each 0.05 degree pixel is ranked through time. Spatial aggregates of these annual ranks show interesting features. For example, 2015 saw the largest percentage of land area (from 50N-50S) with annual precipitation that was among the driest three years since 1981. This was followed by 2016 with the largest percentage of land area that had the first, second or third wettest year since 1981.

By area most of the world had less than average rainfall for fourteen of fifteen years from 1981-1995 while most of the world had wetter than average rainfall for eleven of thirteen years from 2005-2017. Analysis of climate extremes and other metrics, reveal characteristics of rainfall estimates and their ability to identify shocks to food security. Regional patterns and sensitivity of results to spatial and temporal resolutions are also evaluated.