This study explores potential vorticity budgets from the complete Ertel's potential vorticity equation during hurricane genesis. The data sets for these experiments are derived from a high-resolution hurricane forecast that provided reasonable simulation on hurricane genesis. The budgets sort out the relative contribution from the horizontal advection of PV (i.e., related to the conservation of PV in isentropic coordinates), vertical advection of PV (a diabatic contribution), differential heating along the vertical, differential heating along the horizontal, and the frictional contributions. This is aimed to sort out the role of conservation versus non-conservation of PV during the formative stage of a hurricane. The main findings of this study are that conservation of PV was not adequate to explain the large increase in PV during genesis of the storm. The vertical differential of heating made by far the most significant contributions to the changes of PV during the length of the forecast. This term contributed to a net generation of PV over a region of stable air with cyclonic vorticity and increased heating with height. The term is akin to the vortex stretching term in the vorticity equation and is the diabatic stretching of the vortex tube. The effect that convergence has on vorticity in pressure coordinates is entirely analogous to the effect that the diabatic stretching term has on PV in isentropic coordinates. The vertical advection of PV and the horizontal differential of heating each made smaller contributions to changes in PV, but neither was a significant contributor as compared to the other terms. Our analysis includes parcel trajectories along which the PV components (adiabatic and diabatic) of the complete equation are calculated at intervals of every three hours. These were also cast on isentropic surfaces to assess the role of the nonlinear advection of PV and of the diabatic contributions. In the inner rain area of the hurricane a jump in the value of diabatic PV was noted (related to the vertical differential of heating) that was roughly several times larger than that of the nonlinear advection of PV (the latter relates to the conservation of PV while the former is a measure of the non-conservation). / A Thesis Submitted to the Department of Meteorology in Partial Fulfillment of the Requirements for the Degree of Master of Science. / Fall Semester, 2003. / September 25, 2003. / Vortices, Vortex, Hurricane, Diabatic / Includes bibliographical references. / T. N. Krishnamurti, Professor Directing Thesis; Albert I. Barcilon, Committee Member; Paul H. Ruscher, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_180375 |
| Contributors | Ramaswamy, Leela (authoraut), Krishnamurti, T. N. (professor directing thesis), Barcilon, Albert I. (committee member), Ruscher, Paul H. (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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