Global Precipitation: A 17-Year Monthly Analysis Based on Gauge Observations, Satellite Estimates, and Numerical Model Outputs

Abstract

Gridded fields (analyses) of global monthly precipitation have been constructed on a 2.5° latitude-longitude grid for the 17-yr period from 1979 to 1995 by merging several kinds of information sources with different characteristics, including gauge observations, estimates inferred from a variety of satellite observations, and the NCEP-NCAR reanalysis. This new dataset, which the authors have named the CPC Merged Analysis of Precipitation (CMAP), contains precipitation distributions with full global coverage and improved quality compared to the individual data sources. Examinations showed no discontinuity during the 17-yr period, despite the different data sources used for the different subperiods. Comparisons of the CMAP with the merged analysis of Huffman et al. revealed remarkable agreements over the global land areas and over tropical and subtropical oceanic areas, with differences observed over extratropical oceanic areas. The 17-yr CMAP dataset is used to investigate the annual and interannual variability in large-scale precipitation. The mean distribution and the annual cycle in the 17-yr dataset exhibit reasonable agreement with existing long-term means except over the eastern tropical Pacific. The interannual variability associated with the El Niño-Southern Oscillation phenomenon resembles that found in previous studies, but with substantial additional details, particularly over the oceans. With complete global coverage, extended period and improved quality, the 17-yr dataset of the CMAP provides very useful information for climate analysis, numerical model validation, hydrological research, and many other applications. Further work is under way to improve the quality, extend the temporal coverage, and to refine the resolution of the merged analysis.

A new satellite deep convective ice index for tropical climate monitoring: Possible implications for existing oceanic precipitation data sets

“…The CMAP data set [Xie and Arkin, 1997] also employs the WCC and GPI data sets. However, it uses a different data blending methodology than GPCP and incorporates OLR measurements and a modified version of precipitation estimates from an MSU channel 1 algorithm [Spencer, 1993].…”

Absorbing Aerosols and Summer Monsoon Evolution over South Asia: An Observational Portrayal

“…Monthly precipitation data came from the Global Precipitation Climatology Project (GPCP) version 2 (Adler et al 2003), the Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) (Xie and Arkin 1997), and the Climatic Research Unit (CRU) TS 2.1 dataset (Mitchell and Jones 2005). Both GPCP and CMAP precipitation are available on a 2.5°ϫ 2.5°grid, while CRU precipitation is at 0.5°ϫ 0.5°over land only.…”

Simulation of the Global Hydrological Cycle in the CCSM Community Atmosphere Model Version 3 (CAM3): Mean Features

“…It is a merged dataset consisting of satellite microwave and infrared data and surface rain gauge data. The CPC Merged Analysis of Precipitation (CMAP) is a global monthly precipitation dataset on a 2.5 degree grid, covering the period 1979(Xie and Arkin 1997. The National Aeronautics and Space Administration Water Vapor Project global water vapor dataset (NVAP) is a water vapor and liquid water path archive at 1 degree resolution that extends from 1988-1999 (Randel et al 1996).…”