Global 0.25-Degree Future Drought Layers (1980-2100) Based on Downscaled CMIP6 Models and SSP-RCP Combinations, Version 1

Droughts are a natural phenomenon with significant impact on society and the environment. Their frequency and severity are projected to increase toward the end of the century, which makes urgent the analysis of future drought characteristics to inform stakeholders and to allow the investigation of their effects on different domains. In this study, we developed Future Global Drought Layers composed of SPI and SPEI indices for 23 GCMs of the NEX-GDDP-CMIP6 dataset, including historical (1980-2014) data and 4 future projections (2015-2100) under four climate scenarios: SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5. The drought indices were calculated for 3-, 6- and 12-month timescales. The data is gridded in a regular latitude-longitude format, with a spatial resolution of 0.25º (~25 km) and monthly time resolution.

Download the Global Future Drought, Version 1 layers in zipped GeoTIFF format below. Note: Each file is approximately 5.3 GB in volume. For additional details please see this readme.txt file.

Climate variables (precipitation, near-surface relative humidity, surface downwelling shortwave radiation, surface wind speed, near-surface air temperature, maximum near-surface air temperature and minimum near-surface air temperature) were obtained from the NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP-CMIP6) dataset (Thrasher et al., 2022). The drought indices consist of the Standardized Precipitation Index (SPI, Mckee et. al., 1993) and the Standardized Precipitation Evapotranspiration Index (SPEI, Vincente-Serrano et. al., 2010). SPI is based on deviations from precipitation and on a parametric framework from gamma distribution (Mckee et. al., 1993). SPEI is based on deviations from precipitation minus potential evapotranspiration (PET) and on a parametric framework from Generalized Extreme Value (GEV) distribution (Stagge et al., 2015). PET was estimated through the Penman-Monteith (PM) method. Drought events were identified as time periods of negative SPI/SPEI that reaches a value of -1 or lower.

Data set:

Diogo S. A. Araujo and Efthymios I. Nikolopoulos, 2024. Global 0.25-Degree Future Drought Layers (1980-2100) Based on Downscaled CMIP6 Models and SSP-RCP Combinations, Version 1. (Preliminary Release). (Palisades, NY: NASA Socioeconomic Data and Applications Center (SEDAC). https://doi.org/10.7927/4es0-1v73. Accessed DAY MONTH YEAR.

Peer-reviewed publication:

Diogo S. A. Araujo, Brian J. Enquist, Amy E. Frazier, Cory Merow, Patrick R. Roehrdanz, Gabriel M. Moulatlet, Lei Song, Alex Zvoleff, Efthymios I. Nikolopoulos. Global Future Drought Layers Based on Downscaled CMIP6 Models and Multiple Socioeconomic Pathways. In preparation.

This is a preliminary open data release, pending peer review of the data and associated journal articles. Following the peer review process, data curation will be completed by the NASA Socioeconomic Data and Applications Center (SEDAC) and the data will be disseminated through the SEDAC catalog. This work is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0). Users are free to use, copy, distribute, transmit, and adapt the work for commercial and non-commercial purposes, without restriction, as long as clear attribution of the source is provided.