Significant Disparity in Spatiotemporal Changes of Terrestrial Evapotranspiration across Reanalysis Datasets in China from 1982 to 2020

Due to limited observational data, there remains considerable uncertainty in the estimation and spatiotemporal variations of land surface evapotranspiration (ET). Reanalysis products, with their advantages high resolution, global coverage, long-term data availability, have emerged as powerful tools for studying ET. Nevertheless, accuracy reanalysis ET products varies among different reasons these differences not been thoroughly investigated. This study evaluates ability reproduce patterns trends China, using remote sensing water-balance-derived reference. We investigate possible disparity by analyzing three major climatic factors influencing (precipitation, solar radiation, temperature). The findings reveal that compared water balance ET, Global Land Evaporation Amsterdam Model (GLEAM) product is capable reproducing mean, interannual variability, making it suitable validating products. In comparison GLEAM all exhibit consistent climatology spatial distribution but show a clear overestimation, multi-year averages being overestimated 16–40%. There are significant terms trends, attribution. Within common period 2003–2015, demonstrate increasing trends. second-generation Modern-Era Retrospective analysis Research Applications (MERRA2) offline (land-only) replay MERRA (MERRA-Land) could produce similar because precipitation observed precipitation. European Centre Medium-Range Weather Forecasts (ERA5) ERA5-Land cannot capture they obtain decreasing These implications development