Comparing IMERG-v3 with gauge-based precipitation data in Africa
Abstract
Availability of precipitation data is one of the greatest challenges for climate studies in Africa. The rain-gauge stations are often sparse or have a coarse temporal resolution for analysis of meso-scale phenomena. Recent advances in satellite observations have improved the quality of data. However, lack of ground-based rainfall records for validation has posed some concerns for using these data sets, particularly over regions with complex topography or strong convection. The recently-launched "Integrated Multi-satellitE Retrievals for GPM" (IMERG) project has improved the quality and spatio-temporal resolution of precipitation data by integrating observations from several satellites. Here, we have evaluated the performance of IMERG over Africa by comparing it to gauge-based precipitation data from another recently-launched project: TAHMO (Trans-African Hydro- Meteorological Observatory). Several stations from TAHMO project, located in East Africa and West African Monsoon (WAM) region have been used in our analysis. The TAHMO data is recorded at 15-minute intervals, and that enables us to examine the diurnal cycle of precipitation over the region. The results suggest that IMERG captures very well both annual and diurnal cycles in East Africa, near the Lake Victoria. Over the southern Sahel, the annual cycle of IMERG and TAHMO are also similar. However, for the station located in southern Ghana the total precipitation and diurnal cycle of the two present some differences in October and November. These disagreements require further investigation. Overall, IMERG shows some improvements over the TMPA and GPCC First Guess Daily products, though these can vary by region and month.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.H23F1634D
- Keywords:
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- 3354 Precipitation;
- ATMOSPHERIC PROCESSESDE: 1854 Precipitation;
- HYDROLOGYDE: 1855 Remote sensing;
- HYDROLOGYDE: 4303 Hydrological;
- NATURAL HAZARDS