A global 5 km monthly potential evapotranspiration dataset (1982–2015) estimated by the Shuttleworth–Wallace model

<p>As the theoretical upper bound of evapotranspiration (ET) or water use by ecosystems, potential ET (PET) has always been widely used as a variable linking a variety of disciplines, such as climatology, ecology, hydrology, and agronomy. However, substantial uncertainties exist in the current PET methods (e.g., empiric models and single-layer models) and datasets because of unrealistic configurations of land surface and unreasonable parameterizations. Therefore, this study comprehensively considered interspecific differences in various vegetation-related parameters (e.g., plant stomatal resistance and CO<span class="inline-formula">₂</span> effects on stomatal resistance) to calibrate and parametrize the Shuttleworth–Wallace (SW) model for forests, shrubland, grassland, and cropland. We derived the parameters using identified daily ET observations with no water stress (i.e., PET) at 96 eddy covariance (EC) sites across the globe. Model validations suggest that the calibrated model could be transferable from known observations to any location. Based on four popular meteorological datasets, relatively realistic canopy height, time-varying land use or land cover, and the leaf area index, we generated a global 5 km ensemble mean monthly PET dataset that includes two components of potential transpiration (PT) and soil evaporation (PE) for the 1982–2015 time period. Using this new dataset, the climatological characteristics of PET partitioning and the spatiotemporal changes in PET, PE, and PT were investigated. The global mean annual PET was 1198.96 mm with <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">PT</mi><mo>/</mo><mi mathvariant="normal">PET</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="43pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="aebd93389aaaf172a0ea20261d9aa2b5"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="essd-15-4849-2023-ie00001.svg" width="43pt" height="14pt" src="essd-15-4849-2023-ie00001.png"/></svg:svg></span></span> of 41 % and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">PE</mi><mo>/</mo><mi mathvariant="normal">PET</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="44pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="48cf54129caa3e459d789355aed0fbd9"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="essd-15-4849-2023-ie00002.svg" width="44pt" height="14pt" src="essd-15-4849-2023-ie00002.png"/></svg:svg></span></span> of 59 %, controlled moreover by PT and PE of over 41 % and 59 % of the globe, respectively. Globally, the annual PET and PT significantly (<span class="inline-formula"><i>p</i><i>&lt;</i>0.05</span>) increase by 1.26 and 1.27 mm yr<span class="inline-formula">⁻¹</span> over the last 34 years, followed by a slight decrease in the annual PE. Overall, the annual PET changes over 53 % of the globe could be attributed to PT, and the rest to PE. The new PET dataset may be<span id="page4850"/> used by academic communities and various agencies to conduct climatological analyses, hydrological modeling, drought studies, agricultural water management, and biodiversity conservation. The dataset is available at <a href="https://doi.org/10.11888/Terre.tpdc.300193">https://doi.org/10.11888/Terre.tpdc.300193</a> (Sun et al., 2023).</p>