Trends in pan evaporation and actual evapotranspiration across the conterminous U.S.: Paradoxical or complementary?



[1] Pan evaporation (ETpan) has decreased at 64% of pans in the conterminous U.S. over the past half-century. Comparing trends in ETpan and water budget-derived actual evapotranspiration (ET*a), we observe the so-called “Pan Evaporation Paradox,” which we confirm is no more than a manifestation of the complementarity between actual evapotranspiration (ETa) and potential evapotranspiration (ETp). Examining trends in the components of ETa—the radiative energy and regional advective budgets—we show that both components must be considered together to explain the relationship between ETpan and ET*a.