Basic Mechanisms of Tropical Cyclone Size and Structure Change

University Of Arizona, Tucson AZ

Investigators

Abstract

Previous studies of the interaction of tropical cyclones with their large-scale environments have focused primarily on environmental controls on storm tracks and, more recently, rapid changes in intensity. Through a combination of review and analysis of archived storm observations and idealized simulations employing the NCAR/PSU MM5 mesoscale model nested down to 3-km horizontal resolution, this research will investigate the previously unexplored issue of what environmental factors control tropical cyclone size (i.e., diameter) and other broad structural aspects of these storms. Since the large-scale environments in which tropical cyclones are embedded are generally well represented by existing operational weather forecast models, it follows that identifying those environmental characteristics that are most important to determining cyclone size and structure will improve forecasts storm structure and its evolution. The intellectual merit of this research centers upon achieving improved understanding of fundamental physical processes that control evolution of hurricane size and broad structural configuration of accompanying envelopes of damaging winds and heavy precipitation. Broader impacts of this work include training of university graduate and undergraduate students and support of the participation of underrepresented groups. Improved techniques for forecasting changes of tropical cyclone size will in-turn impact operational products including storm surge prediction and proper scoping (in space and time) of coastal evacuation plans in the face of landfalling hurricanes.