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GPCC Drought Index Product

Associated Agencies

Deutscher Wetterdienst, World Meteorological Organization

The Global Precipitation Climatology Centre drought index 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 Prediction 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 Drought Index 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 Drought Index.

The GPCC Drought Index is computed with aggregation periods of 1, 3, 6, 9, 12, 24 and 48 months. Each aggregation period is stored in a separate netCDF file. The GPCC Drought Index has a spatial resolution of 1° latitude by longitude using gridded input data fields at the same resolution.

How to

How to use these data:

Access

GPCC Drought Index – download monthly netcdf files

GPCC Drought Index Product Data Information – information on GPCC Drought Index Product

Documentation

Fan et al., 2008, A global monthly land surface air temperature analysis for 1948 - present, Journal of Geophysical Research, Vol. 113, p. D01103, DOI:10.1029/2007JD008470
McKee et al., 1993, The Relationship of Drought Frequency and Duration to Time Scales, Eighth Conference on Applied Climatology
Pietzsch et al., 2011, A modified drought index for WMO RA VI, Adv. in Science and Research, Vol. 6, p. 275-279, DOI:10.5194/asr-6-275-2011
Thornthwaite, 1948, An approach towards a rational classification of climate, Geographical Review, Vol. 38, p. 55-94
Vicente-Serrano et al., 2009, A Multiscalar Drought Index Sensitive to Global Warming: The Standardized Precipitation Evapotranspiration Index, Journal of Climate, Vol. 23, p. 1696-1718, DOI:10.1175/2009JCLI2909.1

Representative Image
Map of GPCC 1-month drought index