The process by which tropical cyclones evolve from loosely organized convective clusters into well organized systems is still poorly understood. Due to the data sparse regions in which tropical cyclones form, observational studies of tropical cyclogenesis are often more difficult than similar studies of land-based phenomena. As a result, many studies of tropical cyclogenesis are limited to either a few case studies or are forced to rely on simulations to examine the genesis process. The recent PREDICT and GRIP field experiments have provided a new opportunity to gain insight into these processes using unusually dense observations in both time and space. The present study aims at using this new data to perform a detailed analysis of the three-dimensional evolution of both kinematic (e.g. vorticity and divergence) and thermodynamic (i.e. temperature and moisture) in both developing and non-developing tropical convective systems in the western Atlantic. By examining these structures relative to one another, the nature of the system evolution can be better understood. In order to better capture the true state of the atmosphere in these systems, a new method of calculating vorticity, divergence, and deformation from non-gridded observations using Green's theorem is also presented. Previous approaches using Green's theorem on a non-uniform data distribution have either used triangular regions, which are easily implemented in computer code, or hand-selected polygonal regions, which are more robust. The method presented here combines both convenience and robustness and is shown to be significantly more accurate than triangle-based methods on a random distribution of observations as well as on flight-path-based distributions. Using this new data and analysis method, five tropical convective systems are analyzed: three non-developing and two developing. Although the analysis includes only a limited number of cases, the results suggest that there is little kinematic difference between the developing and non-developing systems. In most cases, the only significant difference between developing and non-developing systems is in the distribution of humidity. In the developing cases the vorticity maxima are encased in high relative humidity values at all levels. In the non-developing cases the vorticity maximum either extends into regions of dry air or mid-level vorticity generation non-existent, likely due to an excessively dry middle troposphere. Additionally, many of the cases, both developing and non-developing, exhibit evidence of vorticity generation associated, at mid-levels, with a mesoscale convective system and, at low-levels, with deep convective activity. / A Thesis submitted to the Department of Earth, Ocean, and Atmospheric Science in partial fulfillment of the requirements for the degree of Master of
Science. / Summer Semester, 2012. / June 29, 2012. / Atlantic, cyclogenesis, dropsonde, hurricane, tropical / Includes bibliographical references. / Robert E. Hart, Professor Directing Thesis; Mark Bourassa, Committee Member; Vasu Misra, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_182915 |
| Contributors | Helms, Charles Nelson (authoraut), Hart, Robert E. (professor directing thesis), Bourassa, Mark (committee member), Misra, Vasu (committee member), Department of Earth, Ocean and Atmospheric Sciences (degree granting department), Florida State University (degree granting institution) |
| Publisher | Florida State University, Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text |
| Format | 1 online resource, computer, application/pdf |
| Rights | This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. |
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