Overview: Multi-Source Weighted-Ensemble Precipitation (MSWEP) is a unique gridded precipitation dataset spanning 1979–2017. This product combines a variety of different data sources to create the most accurate gridded precipitation product available.
Full global coverage (all land and oceans)
High spatial (0.1°) and temporal (3 hourly) resolution
Merging of precipitation estimates based on rain gauges (WorldClim, GHCN-D, GSOD, GPCC, and others), satellites (CMORPH, GridSat, GSMaP, and TMPA 3B42RT), and models (ERA-Interim and JRA-55)
Correction of systematic terrestrial precipitation biases using river discharge observations from ~14,000 stations across the globe
Incorporation of daily observations from ~75,000 rain gauges worldwide
Better overall performance than any other precipitation dataset
MSWEP optimally merges a wide range of gauge, satellite, and reanalysis data to provide reliable precipitation estimates over the entire globe. See the following paper for a detailed description of the MSWEP V2 methodology:
The most important changes in V2 compared to V1 include: (i) the introduction of cumulative distribution function and precipitation frequency corrections, to account for spurious drizzle and attenuated peaks evident in V1; (ii) increasing spatial resolution from 0.25° to 0.1° to increase the local relevance of the precipitation estimates (especially important for high water-yield mountainous regions); (iii) the inclusion of ocean areas to enable oceanic studies and terrestrial hydrology studies for coastal areas and small islands; (iv) the addition of precipitation estimates derived from Gridded Satellite (GridSat) thermal infrared imagery for the pre-TRMM era to supplement the reanalysis and gauge data; (v) the use of a daily (rather than monthly) gauge correction scheme that accounts for regional differences in reporting times, to minimize timing mismatches when applying the daily gauge corrections; (vi) the use of a large database of daily gauge observations compiled from several sources to replace the 0.5° CPC Unified dataset; and (vii) extension of the data record to 2017 (MSWEP V1 finished in 2016).