Extended Abstract (108K)P1.63
Exploring the connection of extreme convective events and upper-ocean heat content in the tropical cyclone (Formerly Paper 17C.5)
Paula Ann Hennon, STG, Inc., Asheville, NC
Increasing skill in TC intensity forecasting involves understanding the interactions between complex forcing mechanisms affecting a storm's central pressure and wind strength. Historically, several forcing mechanisms have been identified which act toward TC intensification such as upper ocean interactions, internal storm dynamics, and upper atmosphere circulations. In 1958 Riehl and Malkus proposed that giant cumulonimbus "hot towers" might be a key mesoscale energy transfer mechanism responsible for transporting great amounts of high-energy air from the planetary boundary layer to the upper troposphere. The advent of the ability to monitor the role of hurricane convection from the vantage of space-borne remote sensors, especially SSM/I and TMI passive microwave sensors, has advanced this hypothesis. These data sets have provided detailed glimpses inside the structure of the bursts of convection in tropical cyclones not possible with earlier IR remote sensor imagery that featured only an overpass perspective of the giant cold cloud shield covering the storm center while obscuring the storm's convective structure.
This study consists of a pairing of surveys from the 2000 Atlantic Hurricane season exploring the interactions between the changes in a storm's convective structure and associated changes in the upper-ocean heat content temperature gradient field. The survey of convective burst characteristics such as longevity, size, and structure is taken from the NRL archive of SSM/I and TMI TC satellite imagery. Contemporaneous TOPEX/Poseidon-derived hurricane heat content estimates are then paired in an attempt to ascertain whether convective bursts correspond to changes in the upper-ocean heat content in distinct and obvious ways. Work in this area may provide a resource useful for increasing our understanding of the interactions between the changes in storm dynamics, via the convective burst, and other mechanisms governing tropical cyclone intensity change.
Poster Session 1, Tropical Cyclones, Large-scale Dynamics and Convection
Monday, 29 April 2002, 11:00 AM-12:30 PM
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