Spatial and Temporal Inhomogeneity of Global Precipitation Data

A serious drawback of point precipitation measurement is that it is subject to the systematic errors including especially wind-induced error. This error depends on the particular observational method used, the climate conditions and the gauge site exposure. Since different observational methods are used in different countries and the gauge site exposure in a network varies from exposed to protected, the wind-induced error varies from site to site, causing the precipitation data to be spatially inhomogeneous and non-compatible. Temporal inhomogeneity also can exist owing to changes in observational methods and exposure degrees of a particular gauge site during the observational period. The adjustment for this kind of inhomogeneity using statistical methods does not eliminate the systematic error. Both kinds of inhomogeneities can be eliminated only using the correction procedures. In this way compatible and homogeneous data sets of precipitation for any time period and any size of area can be provided.