This study investigates the environmental factors and the internal processes that contributed to the interrupted rapid decay of Hurricane Joaquin (2015). In-situ data from the Office of Naval Research (ONR) Tropical Cyclone Intensity (TCI) field campaign, global and regional analyses, and satellite and microwave imagery provides a detailed picture of the environment surrounding Joaquin as well as the inner-core region during this period. Additionally, a special dataset comprised of 15-minute temporal frequency vertical wind shear values calculated from rapid-scan atmospheric motion vectors provides an unprecedented look at the high spatial and temporal frequency nature of vertical wind shear, and its role on TC structure and intensity change. Utilization of the high temporal and spatial resolution dropsonde datasets allowed calculations of the vertical tilt of Joaquin to investigate the internal processes. Vertical wind shear and environmental analysis for Hurricane Joaquin discloses a situation in which a major hurricane was able to interrupt a rapid decay based primarily on the relaxation of vertical wind shear, which allowed it to re-align in the low- to mid-troposphere. Further use of the 15-minute VWS calculations to model such a dynamic environmental factor should greatly aid models in accurately forecasting intensity and structure changes.
Meteorology and Physical Oceanography
Naval Postgraduate School
Master of Science in Meteorology and Physical Oceanography
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