The objective of this research is the physics of marine stratus clouds which exist over large portions of the ocean adjacent to the Americas. The competing effects of radiative exchange; vertical motion within the clouds and the heat exchange at the sea surface need to be evaluated experimentally. The necessary measurements will be made using a research aircraft (C- 130) from NCAR. In particular, a new (spectral) radiometer will be used, which should help to determine the relative importance of infrared cooling from the cloud tops. (also known as Marine Stratus Clouds; Radiative Effects and Models)