Cloud and Dynamical Processes of Precipitating Warm Cumuli During Rain In Cumulus over the Ocean (RICO)

University Of Wyoming, Laramie WY

Investigators

Abstract

The "Rain in Cumulus over the Ocean" (RICO) experiment will be a multi-investigator international study of the nature of trade wind Cumulus clouds and of warm-rain formation in such clouds. Within the context of that broader experiment, investigators Geerts and Vali of the University of Wyoming will use the Wyoming King Air and its W-band cloud radar to determine how the air motions in cumulus clouds are associated with the development of precipitation and how trade-wind Cumulus propagate and generate clusters. The first study, which builds upon similar studies of stratocumulus clouds by the same radar, emphasizes the connection between kinematic evolution of the cumulus cells and the development of precipitation. The second features tests of two competing hypotheses regarding cell propagation, one based on dynamic forcing as for a gust front at the edge of the downdraft-driven cold pool, and the second based on enhancement of surface fluxes as a result of downdraft-driven gusts. Many other investigators in RICO will also benefit from the data to be collected by the Wyoming King Air and the Wyoming Cloud Radar. In the course of this work, graduate students will be educated in airborne research methods and the use of the airborne radar, which is becoming an important tool for studies of the fine-scale air motions in clouds. The investigators will also participate in the conduct of a RICO Graduate Student Seminar for the benefit of all graduate students in the project. A further broader impact of the research will be the potential use of the measurements from the cloud radar in the planning for the NASA "CloudSat" radar, a radar that will have properties similar to the Wyoming Cloud Radar.