Terrestrial Hydrology Research Group

Princeton University

Global PDSI


A global dataset of Palmer Drought Severity Index (PDSI) and potential evporation (PE) at 1.0-degree, monthly resolution.


Princeton University Hydroclimatology Group 61-yr (1948-2008) Palmer Drought Severity Index (PDSI) dataset calculated with Sheffield et al. (2006) forcings. These forcings have been updated with: i) extension to 2008; ii) improved sampling procedure for correction of rain day statistics; iii) use of latest versions of CRU, SRB and TRMM products; iv) improved consistency between specific and relative humidity and air temperature; v) correction of relative humidity trends. See Sheffield et al., J. Climate (2006) for details of the observations used and the bias correction and downscaling methodology. The PDSI data have been calculated using the original and self-calibrating (Wells et al., 2004) versions of the PDSI code and for two different potential evaporation algorithms (see Sheffield et al., 2012). There are also versions using different monthly precipitation forcings (CPC, CRU, GPCC, Willmott) and different radiation forcings (merged satellite/empirical and empirical only). See Sheffield et al. (2006,2012) for details."

Sheffield, J., E. F. Wood, and M. L. Roderick, 2012: Little change in global drought over the past 60 years. Nature, 491, 435–438. doi:10.1038/nature11575

Sheffield, J., G. Goteti, and E. F. Wood, 2006: Development of a 50-yr high-resolution global dataset of meteorological f orcings for land surface modeling, J. Climate, 19 (13), 3088-3111

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Jul 26 2013

Initial versions of the PDSI datasets uploaded. There are two types of PDSI (original and self-calibrating (sc)), two versions of the algorithm for PE (Thornthwaite and Penman-Monteith) and four versions of the precipitation forcing (CPC, CRU, GPCC, Willmott).

Mar 27 2013

Both PE datasets updated to correct for minor bugs in the humidity inputs in isolated grid cells and to correct for a data input problem for the version of PE based on empirical radiation. Ignore previous versions.

Mar 18 2013

PE data uploaded. Two versions are available depending on the source of the shortwave and longwave radiation: 1) using the updated PGF (Sheffield et al., 2006) radiation data which is based on a merged and corrected NCEP-NCAR reanalysis and SRB dataset. 2) using an empirical (based on humidity, cloud cover) estimate of radiation (Sheffield et al., 2012).

Jan 14 2013

Initial version of PE data added...

The impact of a water droplet.

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