Validation of satellite rainfall products over East Africa's complex topography

TLDR

The study evaluated ten satellite rainfall products across East Africa’s varied topography by comparing 10‑day aggregated estimates at 1°, 0.5°, and 0.25° resolutions against a station network, grouping them into low‑resolution (2.5° monthly) and high‑resolution (0.1°–1° spatial, 3‑hourly to 10‑daily temporal) categories. TRMM‑3B43, CMAP, CMORPH, TAMSAT, and TRMM‑3B42 were identified as the best performers among the evaluated products.

Abstract

An extensive evaluation of 10 different satellite rainfall products was performed using station network over a complex topography, where elevation varies from below sea level to 4620 m. Evaluation was for two groups of products. The first group had low spatial (2.5°) and temporal (monthly) resolution and included the Global Precipitation Climatology Project (GPCP), the National Oceanographic and Atmospheric Administration Climate Prediction Center (NOAA‐CPC) merged analysis (CMAP), and the Tropical Rainfall Measuring Mission (TRMM‐3B43). The second group comprised products with relatively high spatial (0.1° to 1°) and temporal (3‐hourly to 10‐daily) resolution. These included the NOAA‐CPC African rainfall estimation algorithm, GPCP one‐degree‐daily (1DD), TRMM‐3B42, Tropical Applications of Meteorology using SATellite and other data (TAMSAT) estimates, and the CPC morphing technique (CMORPH). These products were aggregated to a 10‐day total and remapped to spatial resolutions of 1°, 0.5° and 0.25°. TRMM‐3B43 and CMAP from the first group and CMORPH, TAMSAT and TRMM‐3B42 from the second group performed reasonably well.