10.5676/DWD_GPCC/DI_M_V1.1_100
Ziese, Markus
Becker, Andreas
Finger, Peter
Meyer-Christoffer, Anja
Schneider, Udo
Globally Gridded Drought Index with averaging periods 1, 3, 6, 9, 12, 24 and 48 months; retrospective analysis
GPCC Drought Index Product (GPCC_DI) Version 1.1
Global Precipitation Climatology Centre (GPCC) at Deutscher Wetterdienst
2013
1952-01-01/2013-12-31
grid
28.5 MByte per gzip file
gzip compressed netCDF
Summary: The Global Precipitation Climatology Centre drought index (GPCC_DI) is a combination of the Standardized Precipitation Index (SPI; McKee et al., 1993) with the DWD modification according to Pietzsch et al. (2011) and the Standardized Precipitation Evapotranspiration Index (SPEI) according to Vicento-Serrano et al. (2009). The 'Full Data Monthly, Version 7' DOI: 10.5676/DWD_GPCC/FD_M_V7_100 is used as precipitation input data. For the monthly mean temperature data NOAA's Climate Precdiction Center (CPC) Monthly Global Surface Air Temperature Data Set is utilized (Fan and van den Dool, 2008). The temperature data are applied to calculate the potential evapotranspiration (PET) according to Thornthwaite (1948). Parameters to calculate SPI and SPEI were referenced to 1952-2013. Due to the non-applicability of the gamma distribution for precipitation in arid regions the SPI can not be calculated there. On the other hand the PET can not be computed in cold regions applying the formula from Thornthwaite. Hence the GPCC_DI is calculated as the mean of the SPI and SPEI. If one of these indices can not be computed, the one available is used, yielding an almost global coverage of the GPCC_DI. The GPCC_DI is computed with averaging periods of 1, 3, 6, 9, 12, 24 and 48 months. The GPCC_DI has a spatial resolution of 1.0° latitude by longitude using gridded input data fields at the same resolution.
General user recommendations: Users are referred to following gridded Global Precipitation Climate Centre (GPCC) products: GPCC Climatology 1951-2000 (GPCC_Clim) with high representativeness, for application as a reference, and for utilization of the anomaly interpolation method. GPCC Full Data Reanalysis (GPCC_FD) with high accuracy, for, e.g., verification of models, or for analysis of historic global precipitation, or for research concerning the global water cycle, e.g., trend and teleconnection analyses. GPCC Monitoring Product (GPCC_MP) with high availability and reasonable timeliness, for applications like calibration of satellite data, or early annual reporting. GPCC First Guess Product (GPCC_FG) with high timeliness, to be applied for, e.g., drought monitoring. GPCC First Guess Daily Product (GPCC_FG_D) with high timeliness, to be applied for, e.g., drought monitoring.