Radar analysis of the evolution of trade wind clouds observed during RICO

In this paper we use dual wavelength and dual polarization radar measurements to study the entire life cycle of trade wind clouds that have been observed during the Rain in Cumulus over the Ocean (RICO) field experiment. We track radar echoes of clouds using PPI scans from the National Center for Atmospheric Research (NCAR) S-Pol-Ka radar. For each cloud tracked by radar we construct time-height cross-sections of S-band radar reflectivity and other radar-derived quantities. From these time-height cross-sections we identify different microphysical stages throughout the entire life cycle of trade wind clouds. Early results show that several clouds lived unexpectedly long, and some even developed several rainshafts throughout their lifetime. To date we have analyzed clouds from two days. These two days represent weak and strong wind conditions, where differences in clear-air giant nuclei particle concentrations were apparent, as measured by the FSSP probe, which was mounted on the NCAR C-130 wing tip. Differences in the evolution of the radar signatures on these two days will be discussed.