GPCC Interpolation Test Dataset at 1.0°

The GPCC Interpolation Test Dataset (ITD) was created to provide "open" precipitation data for users to compare their interpolation results with the GPCC interpolation procedure. Depart from the operational interpolation of anomalies, monthly precipitation totals were interpolated, because the necessary long term means to compute the anomalies could not be provided. As described in Becker et al. (2013; DOI:10.5194/essd-5-71-2013), the interpolation was done at a finer subgrid and subsequent area and land portion weighting. Only (aggregated) monthly precipitation totals from the GHCN dataset (e.g., Menne et al., 2012; DOI: 10.1175/JTECH-D-11-00103.1) were used as input data. These data are additionally quality controlled by GPCC and can be different to the original GHCN data. Station coordinates were extracted from the GPCC data base and can therefore differ from the original GHCN coordinates. Within this dataset, gridded monthly precipitation totals for 1988, as NetCDF archive, and the underlying station data, as ASCII file with longitude, latitude and precipitation total, are provided. This dataset is applicable for the comparison of interpolation schemes, but not for hydrological or climatological analyses!