Three‐Dimensional Surface Downwelling Longwave Radiation Clear‐Sky Effects in the Upper Colorado River Basin

In complex terrain, non-parallel surfaces receive emitted radiation from adjacent surfaces. Qualitatively, where surface skin temperatures and lower tropospheric temperature humidity are not uniform, the downwelling longwave (DLR) will be determined just by atmosphere above a given location, but also temperatures. We quantify this three-dimensional radiative effect over Upper Colorado River Basin in clear-sky conditions calculating DLR with observed land-surface ECOSTRESS. find that is due to terrain-subtended sky-view represents ∼22% of flux, rising ∼28% ∼24% East Southeast Basin, respectively, can >50% extreme cases. The common omission atmospheric models leads an underestimation especially at higher elevations, which has significant implications for mountainous ecohydrology simulations.