9529771 Molinari This project involves the study of the influence of three aspects of large-scale atmospheric flow on tropical cyclogenesis. Previous observational studies have suggested that interactions between the negative vorticity anomalies associated with upper tropospheric outflow from anticyclones and environmental positive vorticity anomalies are related to the strength of those anomalies. A shallow water model will be used to conduct numerical experiments to try to better understand the nature of these interactions in subsequent tropical cyclone development. The second part of the project involves an observational study of the role the direction of vertical wind shear in tropical cyclone development, particularly relative to the opposing influence of upper level vorticity. This will be accomplished using ECMWF gridded analyses. The third part will consist of an examination of the role of the time-averaged potential vorticity field on the genesis and movement of tropical cyclones in the Atlantic and eastern Pacific through analysis of the ECMWF gridded fields and numerical modeling work. ***
