A characterization of cold pools below marine trade wind cumuli

Cold pools under marine cumuli, formed by evaporation of rain below cloud base, have been hypothesized (Jensen et al, 2000) to control the forcing and organization of new cumulus elements. During the RICO experiment, many cold pools were observed during circular flight legs near sea surface.

The purpose of the present study is to characterize these cold pools in terms of size and frequency (percentage of flight leg), and to describe the following properties as deviations from the median values of the mixed layer: temperature, humidity, horizontal velocity, pressure perturbation, and aerosol particles.

The cold pools temperatures were up to 1 degree colder than the remainder of the mixed layer, and cold pools of 0.5 degrees were found on nearly every flight leg when precipitating clouds were observed.