Potential evapotranspiration derived from HadUK-Grid 1km gridded climate observations 1969-2024 (Hydro-PE HadUK-Grid)

This dataset was derived from HadUK-Grid Gridded Climate Observations on a 1km grid over the UK: v1.0.3.0 for 1969-2020 inclusive, v1.1.0.0 for 2021, v1.2.0 for 2022, and v1.3.1.ceda for 2023-2024 inclusive. (https://catalogue.ceda.ac.uk/uuid/4dc8450d889a491ebb20e724debe2dfb). HadUK-Grid is a gridded dataset derived from observed meteorological station data. The daily total potential evapotranspiration (PET; kg m-2 d-1) was calculated using the Penman-Monteith equation parameterised for a well-watered grass surface. The daily total potential evapotranspiration with interception correction (PETI; kg m-2 d-1), was calculated as PET then a correction added for interception by a grass canopy on days with non-zero precipitation.

The HadUK-Grid meteorological variables used were: daily maximum and minimum air temperature at 1.5 m (°C), daily precipitation (mm d-1), monthly mean water vapour pressure (hPa), monthly mean sea level pressure (hPa), monthly total sunshine hours (hours) and monthly mean wind speed at 10 m (m s-1). Other variables used were the surface elevation (m) and Ångström coefficients a, b and c. A description of the methodology is available in the supporting documentation.