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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

A Numerical Modelling Study of Tropical Cyclone Sidr (2007): Sensitivity Experiments Using the Weather Research and Forecasting (WRF) Model

Shepherd, Tristan James January 2008 (has links)
The tropical cyclone is a majestic, yet violent atmospheric weather system occurring over tropical waters. Their majesty evolves from the significant range of spatial scales they operate over: from the mesoscale, to the larger synoptic-scale. Their associated violent winds and seas, however, are often the cause of damage and destruction for settlements in their path. Between 10/11/07 and 16/11/07, tropical cyclone Sidr formed and intensified into a category 5 hurricane over the southeast tropical waters of the northern Indian Ocean. Sidr tracked west, then north, during the course of its life, and eventually made landfall on 15/11/07, as a category 4 cyclone near the settlement of Barguna, Bangladesh. The storm affected approximately 2.7 million people in Bangladesh, and of that number 4234 were killed. In this study, the dynamics of tropical cyclone Sidr are simulated using version 2.2.1 of Advanced Weather Research and Forecasting — a non-hydrostatic, two-way interactive, triply-nested-grid mesoscale model. Three experiments were developed examining model sensitivity to ocean-atmosphere interaction; initialisation time; and choice of convective parameterisation scheme. All experiments were verified against analysed synoptic data. The ocean-atmosphere experiment involved one simulation of a cold sea surface temperature, fixed at 10 °C; and simulated using a 15 km grid resolution. The initialisation experiment involved three simulations of different model start time: 108-, 72-, and 48-hours before landfall respectively. These were simulated using a 15 km grid resolution. The convective experiment consisted of four simulations, with three of these using a different implicit convective scheme. The three schemes used were, the Kain-Fritsch, Betts-Miller-Janjic, and Grell-Devenyi ensemble. The fourth case simulated convection explicitly. A nested domain of 5km grid spacing was used in the convective experiment, for high resolution modelling. In all experiments, the Eta-Ferrier microphysics scheme, and the Mellor-Yamada-Janjic planetary boundary layer scheme were used. As verified against available observations, the model showed considerable sensitivity in each of the experiments. The model was found to be well suited for combining ocean-atmosphere interactions: a cool sea surface caused cyclone Sidr to dissipate within 24 hours. The initialisation simulations indicated moderate model sensitivity to initialisation time: variations were found for both cyclone track and intensity. Of the three simulations, an initialisation time 108 hours prior to landfall, was found to most accurately represent cyclone Sidr’s track and intensity. Finally, the convective simulations showed that considerable differences were found in cyclone track, intensity, and structure, when using different convective schemes. The Kain-Fritsch scheme produced the most accurate cyclone track and structure, but the rainfall rate was spurious on the sub-grid-scale. The Betts-Miller-Janjic scheme resolved realistic rainfall on both domains, but cyclone intensity was poor. Of particular significance, was that explicit convection produced a similar result to the Grell-Devenyi ensemble for both model domain resolutions. Overall, the results suggest that the modelled cyclone is highly sensitive to changes in initial conditions. In particular, in the context of other studies, it appears that the combination of convective scheme, microphysics scheme, and boundary layer scheme, are most significant for accurate track and intensity prediction.
112

Evolution of frontal structure associated with extratropical transitioning hurricanes

Maue, Ryan Nicholas. O'Brien James J. January 2004 (has links)
Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. James O'Brien, Florida State University, College of Arts and Sciences, Dept. of Meteorology. Title and description from dissertation home page (viewed Jan. 13, 2005). Includes bibliographical references.
113

Boundary layer structure in landfalling tropical cyclones

Maxham, William Davidson. Ruscher, Paul. January 2004 (has links)
Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. Paul Ruscher, Florida State University, College of Arts and Sciences, Dept. of Meteorology. Title and description from dissertation home page (viewed Jan 18, 2005). Includes bibliographical references.
114

Observational analysis of shallow water response to passing hurricanes in Onslow Bay, NC in 1999 /

Speckhart, Benjamin L. January 2004 (has links) (PDF)
Thesis (M.S.)--University of North Carolina at Wilmington, 2004. / Includes bibliographical references (leaves : 60-61).
115

Study of contraflow operations for hurricane evacuation

Shinouda, Michael Magdy Rizk. January 2009 (has links) (PDF)
Thesis (M.S.)--University of Alabama at Birmingham, 2009. / Title from PDF t.p. (viewed July 21, 2010). Includes bibliographical references (p. 90-93).
116

The role of the ocean in convective burst initiation implications for tropical cyclone intensification /

Hennon, Paula Ann, January 2005 (has links)
Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Includes bibliographical references (p. 152-162).
117

A quality control procedure for assimilating AIRS radiance data into a mesoscale model

O'Connor, Janna Elizabeth. Zou, Xiaolei. January 2006 (has links)
Thesis (M.S.)--Florida State University, 2006. / Advisor: Xiaolei Zou, Florida State University, College of Arts and Sciences, Dept. of Meteorology. Title and description from dissertation home page (viewed June 13, 2006). Document formatted into pages; containsxi, 65 pages. Includes bibliographical references.
118

Two of a kind comparing photographic media coverage for Hurricanes Katrina and Ike /

Barth, Laura J. Stone, Sara J. January 2009 (has links)
Thesis (M.A.)--Baylor University, 2009. / Includes bibliographical references (p. 50-51).
119

Impact of Hurricanes on Caretta caretta Nesting Success, Hatching Success and Washout Rate in Broward County

Gilbert, Collette F. 01 August 2013 (has links)
Hurricanes can cause considerable damage along the coastlines of the United States. There are very little data relating hurricanes and sea turtle nesting. Hurricane season (June- November) and sea turtle nesting season, for the study period, (March- September) overlap in Broward County, Florida. This paper examines the relationship between the Hurricane Impact Index (HII) and hatching success of loggerhead sea turtles (Caretta caretta) and HII and washout rate. For ten of the eleven storms studied, there was no significant relationship between HII and hatching success (percent). Tropical Storm Ophelia (2005) showed a significantly higher (p=0.0206) hatching success after the storm’s passing than before the storm’s passing. There was a significant relationship between washout rate and HII (p=0.026).
120

Evaluation and Predictability of Observation-based Surface Wind Asymmetric Structure in Tropical Cyclones

Klotz, Bradley 30 March 2017 (has links)
Surface wind speeds are an important and revealing component of the structure of tropical cyclones (TCs). To understand the asymmetric structure of surface winds in TCs associated with differences in formation region, environmental wind shear, storm forward motion, and TC strength and intensification, a twelve year database of satellite scatterometer data are utilized to produce composite total wind speed and Fourier-derived, low wavenumber analyses. A quantified asymmetry is determined as a function of TC intensity and reveals the tropical storms are influenced by wind shear at all TC-centric radii but only for areas away from the radius of maximum wind in hurricanes. Additionally, an increase of absolute angular momentum flux has a preference for the downshear-right quadrant, and the low wavenumber maximum develops downwind of this momentum transport. Further evaluation of the asymmetric structure with respect to wind shear’s relation to motion and impacts during TC intensity change are also considered. A composite rapid intensification event is produced and compared to overlapping satellite rain estimates. Results indicate that the TC becomes more symmetric during intensification and the phase of the maximum asymmetry rotates from a downshear-left direction to upshear-left direction after the intensification slows. The rain or convective maximum is generally located upwind of the surface wind maximum at the early stages of intensification and is coincident with the region of large angular momentum transport, which supports the idea that the surface wind asymmetry is likely a consequence of convective or other processes. Using data from a regional TC model, it is also determined that the scatterometer data are useful for model verification of tropical storms and non-major hurricanes and performs similar to or better than the standard tool at forecast lead times up to 60 hours. Preliminary comparisons of model-derived surface wind asymmetry relative to rain generally confirm the observational results.

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