Satellite observed trends of global mean net atmospheric shortwave and longwave irradiances and diabatic heating by precipitation

Abstract

The changes in global mean precipitation over recent decades are poorly understood despite their fundamental importance to climate change prediction. We provide an observational verification of the physical link between global precipitation and net atmospheric radiative cooling. April 2006 through December 2024, the net atmospheric total (shortwave + longwave) cooling increases at a rate of 0.11 ± 0.31 watts per square meter per decade (Wm⁻² dec⁻¹). Trends of longwave cooling and shortwave heating are 0.76 ± 0.48 and 0.64 ± 0.27 Wm⁻² dec⁻¹, respectively. The longwave trend is a result of partial cancelation among contributions from increasing surface skin temperature, air temperature, and water vapor. Increasing shortwave absorption is caused by increasing water vapor. The trend of global mean diabatic heating by precipitation is 0.03 ± 0.61 Wm⁻² dec⁻¹. These results observationally confirm that an absence of current global precipitation trends is consistent with net atmospheric radiative cooling trends explained by nearly balanced changes between longwave cooling and shortwave heating.