Version 3 of the Global Aridity Index and Potential Evapotranspiration Database

Robert J Zomer; Jianchu Xu; Antonio Trabucco

doi:10.1038/s41597-022-01493-1

Version 3 of the Global Aridity Index and Potential Evapotranspiration Database

Sci Data. 2022 Jul 15;9(1):409. doi: 10.1038/s41597-022-01493-1.

Authors

Robert J Zomer^{1

2}, Jianchu Xu^{3

4}, Antonio Trabucco⁵

Affiliations

¹ Centre for Mountain Futures, Kunming Institute of Botany, Chinese Academy of Science, Kunming, 650201, Yunnan, China.
² CIFOR-ICRAF China Program, World Agroforestry (ICRAF), Kunming, China.
³ Centre for Mountain Futures, Kunming Institute of Botany, Chinese Academy of Science, Kunming, 650201, Yunnan, China. J.C.Xu@cgiar.org.
⁴ CIFOR-ICRAF China Program, World Agroforestry (ICRAF), Kunming, China. J.C.Xu@cgiar.org.
⁵ Euro-Mediterranean Center on Climate Change, IAFES Division, Sassari, Italy.

Abstract

The "Global Aridity Index and Potential Evapotranspiration Database - Version 3" (Global-AI_PET_v3) provides high-resolution (30 arc-seconds) global hydro-climatic data averaged (1970-2000) monthly and yearly, based upon the FAO Penman-Monteith Reference Evapotranspiration (ET₀) equation. An overview of the methods used to implement the Penman-Monteith equation geospatially and a technical evaluation of the results is provided. Results were compared for technical validation with weather station data from the FAO "CLIMWAT 2.0 for CROPWAT" (ET₀: r² = 0.85; AI: r² = 0.90) and the U.K. "Climate Research Unit: Time Series v 4.04" (ET₀: r² = 0.89; AI: r² = 0.83), while showing significant differences to an earlier version of the database. The current version of the Global-AI_PET_v3 supersedes previous versions, showing a higher correlation to real world weather station data. Developed using the generally agreed upon standard methodology for estimation of reference ET₀, this database and notably, the accompanying source code, provide a robust tool for a variety of scientific applications in an era of rapidly changing climatic conditions.