A Cloud‐Free Approach to Modeling Daily Downwelling Longwave Irradiance at Global Scale

Parametric modeling of downwelling longwave irradiance under all-sky conditions (LW↓) typically involves “correcting” a clear- (or non-overcast) sky model estimate using solar-irradiance-based proxies cloud cover in lieu actual given uncertainties and measurement challenges the latter. While such approaches are deemed sound, their application time space is inherently limited. We report on correction free solar irradiance-derived that applicable at true daily (24 hr) global scales. The new “cloud-free” demonstrates superior performance range environments relative to existing cloud-free corrections based solar-derived cloudiness proxies. Literature-based benchmarking indicates often comparable to—and some cases to—performances yielded by conventional parametric employing locally or regionally calibrated parameters, as well performances satellite-based algorithms.