12B.3A
A Satellite-Derived Census of Convective Bursts in Tropical Cyclones and Their Relationship to Storm Lifecycle
Paula Ann Hennon, Ohio State University, Columbus, OH; and J. B. Halverson
The term "convective burst" has been variously used to describe an episode of long-lived, intense convection occurring in tropical cyclones. A burst usually assumes the form of a circular, rapidly expanding cold cloud shield near the storm center, which contains one or more intense cumulonimbus towers. Most of the nearly two dozen published case studies on bursts have related them to intensification of the storm, although not all hurricane specialists agree that this is necessarily the case. Furthermore, the mechanisms by which convective bursts may enhance development remain elusive.
In this study, we have surveyed nearly 250 tropical cyclones spanning three years to develop a census on global convective burst occurrence. We examine the incidence of bursts according to ocean basin. The bursts have been identified through systematic examination of the GEO infrared cloud top and microwave imager data. Nearly 80% of all tropical cyclones contain one or more bursts during some stage of the lifecycle. Results are presented that relate burst occurrence to specific stages in the storm evolution, time of day, and location with respect to storm center and direction of storm motion. The analyses provide clues on the relative importance of bursts and the physical mechanisms by which bursts might enhance storm development.
.Session 12B, Convection, waves, and precipitation V
Thursday, 6 May 2004, 8:00 AM-9:30 AM, Napoleon I Room
Previous paper Next paper