Radiational cooling

From Glossary of Meteorology

radiational cooling

In meteorology, the result of radiative cooling of the earth's surface and adjacent air.

Radiational cooling occurs, as is typical on calm, clear nights, whenever the longwave emission from the surface is not balanced by significant amounts of absorbed shortwave radiation or downwelling longwave from the atmosphere above the surface, and there are no nonradiative sources of sufficient energy to make up the difference.