|Coverage||Global (90N-90S, 0-360E)|
January 1979 - August 2002 (Version 9906)
August 2002 - Present (Version 0208)
|Resolution||2.5 x 2.5 degree, monthly|
Several climate rainfall products, which merge rainfall estimates from a variety of satellite and ground-based sources are currently available going back to January of 1979 and continuing through the present. While the combination of data from these multiple sensors/sources provides long-term climate rainfall datasets suitable for climate studies, there are a number of issues affecting their use for some climate applications. These include discontinuities in the component data sets, differences in the calibration methods, and the methodology used to weight the individual rain estimates.
V9906: Available January 1979 - August 2002
V0208: Available August 2002 - Present
This is a merged dataset combining satellite rainfall estimates from the Outgoing Longwave Radiation (OLR) Precipitation Index (OPI) with ground-based rain gauge observations from the Climate Anomaly Monitoring System (CAMS). The OPI estimates are computed from NOAA polar-orbiting IR window channel data using the technique developed by Xie and Arkin . While it is recognized that the OPI has significant limitations for many climate applications, the merged CAMS-OPI dataset was developed primarily requiring near real-time applications. For research purposes users are encouraged to look at either the GPCP or CMAP merged climate rainfall datasets, both of which have better quality control measures and include satellite passive microwave rain estimates. A complete description of the CAMS-OPI merged dataset is provided by Janowiak and Xie .
This dataset is available through the CAMS-OPI web site at NOAA's Climate Prediction Center