Version 3 of the Global Aridity Index and Potential Evapotranspiration Database

Area of Science:

• Hydrology
• Climatology
• Environmental Science

Background:

• Accurate hydro-climatic data is crucial for understanding environmental changes.
• Existing global datasets have limitations in resolution and validation.
• The FAO Penman-Monteith equation is a standard for estimating reference evapotranspiration.

Purpose of the Study:

• To present the Global Aridity Index and Potential Evapotranspiration Database - Version 3 (Global-AI_PET_v3).
• To provide high-resolution, spatially explicit hydro-climatic data.
• To offer a validated and robust dataset for scientific applications.

Main Methods:

• Implementation of the FAO Penman-Monteith Reference Evapotranspiration (ET0) equation.
• Geospatial analysis to create high-resolution (30 arc-seconds) global data.
• Technical validation against FAO CLIMWAT 2.0 and UK Climate Research Unit datasets.

Main Results:

• Global-AI_PET_v3 provides monthly and yearly averaged data from 1970-2000.
• Validation showed strong correlations with weather station data (ET0: r²=0.85-0.89; AI: r²=0.83-0.90).
• The current version demonstrates superior accuracy over previous iterations.

Conclusions:

• Global-AI_PET_v3 is a significant improvement over prior versions.
• The database, including its source code, is a valuable resource for climate change studies.
• This dataset supports diverse scientific applications in a changing climate.