A Study of Relationships between Florida Thunderstorm Properties and Corresponding Anvil Cloud Characteristics

Abstract

Tropical thunderstorms produce large amounts of cirrus anvil clouds, which have a large effect on the climate system. Modeling of the cirrus anvil is a very important factor in the driving processes in atmospheric, climate, and radiation budget models. The current research project is focused on determining the relationships between the thunderstorm intensity and cirrus anvil characteristics of storms during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers?Florida Area Cirrus Experiment (CRYSTAL-FACE). During July 2002, 19 different storms were selected for analysis. A vertical profile of reflectivity was extracted for each cell in which the maximum reflectivity, and maximum 10- and 40-dBZ height were identified. A majority of the thunderstorms in this study were single cells or isolated multicell clusters initiated from outflow boundaries or sea-breeze interactions. The results show that a general thunderstorm life cycle characteristic time sequence was determined, finding that the maximum reflectivity occurred on average 10 min after the cell first appeared in the base scan reflectivity image. The anvil origin and maximum height were found to occur approximately 10 and 25 min after maximum reflectivity, respectively. The anvil?s mean particle size was found to increase with time and decrease with altitude. The opposite relationship holds true for the particle concentration. Contour analysis has shown that the particle size increased with increased thunderstorm intensity and time after maximum reflectivity. An increase in convective core intensity corresponds to increased anvil particle concentrations early after maximum reflectivity, as was observed.