2011-02-03: Evaluation of rainfall retrievals from SEVIRI reflectances over West Africa using TRMM-PR and CMORPH

Precipitation is a crucial factor in the hydrological cycle and needs to be measured at a high temporal and spatial resolution. Over several regions, such as the tropical areas and over the oceans, the amount of observations from rain gauges and rain radar is insufficient. Geostationary satellite instruments, like SEVIRI onboard the Meteosat Second Generation (MSG) satellites, are suitable to observe precipitation characteristics at various spatio-temporal scales.
In the study of Wolters et al. (2011), it is shown that rainfall retrievals from SEVIRI reflectances using the Cloud Physical Properties (CPP) algorithm are accurate in both retrieving instantaneous and accumulated precipitation when compared against observations from TRMM Precipitation Radar and the Climate Prediction Center MORPHing Technique (CMORPH). In addition, the development of the 2005 and 2006 West African monsoon can be well followed using the rainfall retrievals. Finally, the added value of the high temporal resolution (15 minutes) of SEVIRI to detect precipitation characteristics at sub-daily scale is demonstrated.
Mean accumulated daily precipitation (expressed in mm d-1) for May September 2005 from (left) CPP on SEVIRI reflectances and (right) CMORPH. For both datasets observations at 09:00, 12:00, and 15:00 UTC were included and a uniform distribution of precipitation throughout the day was assumed.