Intercomparison of Global Precipitation Products: The Third Precipitation Intercomparison Project (PIP–3)

Abstract
A set of global, monthly rainfall products has been intercompared to understand the quality and utility of the estimates. The products include 25 observational (satellite based), four model, and two climatological products. The results of the intercomparison indicate a very large range (factor of 2 or 3) of values when all products are considered. The range of values is reduced considerably when the set of observational products is limited to those considered quasi–standard. The model products do significantly poorer in the Tropics, but are competitive with satellite–based fields in midlatitudes over land. Over ocean, products are compared to frequency of precipitation from ship observations. The evaluation of the observational products points to merged data products (including rain gauge information) as providing the overall best results. Abstract A set of global, monthly rainfall products has been intercompared to understand the quality and utility of the estimates. The products include 25 observational (satellite based), four model, and two climatological products. The results of the intercomparison indicate a very large range (factor of 2 or 3) of values when all products are considered. The range of values is reduced considerably when the set of observational products is limited to those considered quasi–standard. The model products do significantly poorer in the Tropics, but are competitive with satellite–based fields in midlatitudes over land. Over ocean, products are compared to frequency of precipitation from ship observations. The evaluation of the observational products points to merged data products (including rain gauge information) as providing the overall best results.