BACKGROUND OF SATELLITE DATA (CHIRPS)

The U.S. Geological Survey Earth Resources Observation Science Center (USGS) and University of California, Santa, Barbara (UCSB), Climate Hazard Group developed utilized satellite observations, average precipitation from rainfall stations and rainfall predictors such us elevation, latitude and longitude to build high resolution (0.05x0.05 degree), Africa dekadal and monthly precipitation datasets called the Climate Hazard Group Infrared Precipitation with Global Telecommunication System (GTS) stations (CHIRPS). The datset is available since 1981 to present. The updated CHIRPS dataset can be freely accessed on the website: ftp://ftp.chg.ucsb.edu/pub/org/chg/products/CHIRPS-2.0/

BLENDING GRIDDED DATASETS FOR EAC/IGAD REGION

Further processing to blend station observations with unbiased satellite rainfall estimates was used to produce the 1981 to present CHIRPS for the Greater Horn of Africa region. Approximately 102 stations from the IGAD Member-States, including Tanzania, Rwanda and Burundi were used to create high resolution (0.05x0.05 degree) blended, gridded dekadal and monthly precipitation datasets available at ICPAC using GeoCLIM tool. GeoCLIM is a geostatistical tool developed by USGS in collaboration with UCSB and USAID Famine Early Warning System Network (FEWSNET) for climatological analysis of historical rainfall and temperature data, in support of the USAID PREPARED and Global Climate Change activities.

The blending methodology in GeoCLIM utilizes the inverse distance weighting interpolation technique to generate station grids combined with satellite data to produce a new improved dataset, a combination of insitu and satellite data at 5km resolution. The blended data for the EAC/IGAD region has been generated at monthly timescales for the period 1981 to present. This dataset can freely be accessed from the ICPAC website

346 is the number of stations were used in the blending of the EAC Chirps data from 1981 – 2013.

The number of stations which goes into the blending of the GHA/ICPAC Chirps data is 100 stations from 1918 – 2013. GHA Metadata