Global Evapotranspiration Datasets Assessment Using Water Balance in South America

Evapotranspiration (ET) connects the land to atmosphere, linking water, energy, and carbon cycles. ET is an essential climate variable with a fundamental importance, accurate assessments of spatiotemporal trends variability in are needed from regional continental scales. This study compared eight global actual datasets (ETgl) average ensemble (ETens) based on remote sensing, reanalysis, land-surface, biophysical models computed basin-scale water balance (ETwb) South America monthly time scale. The 50 small-to-large basins covered major rivers different biomes types. We also examined magnitude, seasonality, interannual ET, comparing ETgl ETens ETwb. Global were evaluated between 2003 2014 following datasets: Breathing Earth System Simulator (BESS), ECMWF Reanalysis 5 (ERA5), Land Data Assimilation (GLDAS), Evaporation Amsterdam Model (GLEAM), MOD16, Penman–Monteith–Leuning (PML), Operational Simplified Surface Energy Balance (SSEBop) Terra Climate. By using ETwb as basis for comparison, correlation coefficients ranged 0.45 0.60 (ETens), RMSE 35.6 40.5 mm·month−1 (MOD16). Overall, estimates 0 150 most America, while showed maximum rates up 250 mm·month−1. varied by hydroclimatic regions: (i) located humid climates low seasonality precipitation, including Amazon, Uruguay, Atlantic basins, yielded weak ETwb, (ii) tropical semiarid (areas where precipitation demonstrates strong São Francisco, Northeast Atlantic, Paraná/Paraguay, Tocantins basins) moderate-to-strong coefficients. An assessment demonstrated disagreement tropics (in Amazon), showing wide range variability. However, tropical, subtropical, climates, Tocantins, Paraná, Paraguay, (Northeast, East, South), we found stronger agreement Assessing enables understanding land–atmosphere exchanges improvement estimation monitoring management.