Novel dataset devised for climate research

A team led by academics from Cardiff University has published an open-access dataset to aid future researchers in studying the effects of climate change on the water cycle around the world.

This open-source data set focuses on a phenomenon called Potential EvapoTranspiration (PET), which quantifies how much water the atmosphere can hold at any given time, and is calculated by combining the energy, aerodynamics, and humidity at surface level.

This is the first global dataset of its kind, providing PET data over an hourly resolution (hPET), going back almost 4 decades. Having open access to this kind of high-resolution data will allow researchers to understand, for example, how short-lived rainfall can affect soil moisture and uptake by plants.

This is only one example, being able to track this data is important for flood management authorities to assess conditions that lead to flooding, water companies to address seasonal supply and demand, and ecologists to study how certain vegetation species or crops become stressed in drought.

To build this dataset, the team led by Dr Michael Singer of the School of Earth and Environmental Sciences based their work on output from the ERA5-Land reanalysis dataset, which is part of Copernicus Climate Change Service (C3S) Climate Data, and compared their results to pre-existing datasets. This demonstrated that hPET showed a similar overall pattern to global PET variation, consistent with the existing datasets.

With the improvements in resolution of both timescales and locations around the globe provided by the hPET dataset, the team has provided a valuable new tool to study the effects of potential evapotranspiration under a changing climate.

Researchers plan to update this dataset yearly, ensuring users can have both historical and up-to-date information from which to base research and plan interventions.

The dataset was developed with Dr. Mark Cuthbert and Andrés Quichimbo from Cardiff along with researchers from the University of Bristol and Ghent University.

The paper ‘Hourly potential evapotranspiration at 0.1° resolution for the global land surface from 1981-present’ can be accessed online in the Nature Publishing Group journal, Scientific Data.