Comparison of CMORPH and TRMM-3B42 over mountainous regions of Africa and South America

Abstract

Two satellite rainfall estimation algorithms, CMORPH and TMPA, are evaluated over two mountainous regions at daily accumulation and spatial resolution 0.25°. The evaluated TMPA products are TRMM-3B42 and TRMM-3B42RT. The first of the two validations region is located over the Ethiopian highlands in the Horn of Africa. The second is located over the highlands of Columbia in South America. Both sites are characterized by a very complex terrain. Relatively dense station networks over the two sites are used to validate the satellite products. The correlation coefficients between the reference gauge data and the satellite products were found to be low. Besides, the products underestimate both the occurrence and amount of rainfall over both validation sites. These were attributed, at least partly, to orographic warm rain process over the two regions. The performance over Colombia was better compared to that for Ethiopia. And CMORPH has exhibited better performance as compared to the two TRMM products. © 2010 Springer Science+Business Media B.V.