Studies have shown that urban areas enhance mesoscale precipitation but have not revealed if urban areas have the same effect on synoptic scale precipitation. This study used Multi-Precipitation Estimator (MPE) and Next-Generation Weather Radar (NEXRAD) stage III data to examine the effect of urban areas on rainfall associated with hurricanes and tropical storms from 1976–2005. These urban areas were divided into upwind and downwind areas where 6-hour precipitation totals were calculated and compared. Results displayed that 69.2% of urban areas had greater rainfall in the upwind area. Statistical analyses revealed that there is a larger range of higher precipitation values in the upwind area and a smaller range of lower precipitation values in the downwind area. Therefore, instead of urban areas enhancing tropical rainfall it weakens the rainfall. Based on the results, there is no relationship between urban areas and enhanced rainfall; however, there is a relationship between the distribution of precipitation and urban areas.

An extensive database of the tracks of tropical cyclones in the North Atlantic Ocean since 1851 is known as the North Atlantic Hurricane Database (HURDAT). While this database is valuable to public and private agencies, many of the deadliest hurricanes on record occurred prior to 1851. This study will address the research problem of the availability of historical information and the feasibility of collecting data and producing historical tropical cyclone tracks. This thesis describes a methodology for identifying tropical cyclones that existed during the one hundred year period from 1751-1850 referred to as the “pre-HURDAT era” in this study. Uncovering historical tropical cyclone tracks are important for researchers seeking long term patterns in the climate record. This study is a synthesis of all readily available historical data which can be used to identify the tracks of documented tropical cyclones that occurred during the pre-HURDAT era. To emphasize the applicability of historical hurricane tracks, a study comparing landfall patterns of landfalling east coast hurricanes was also done. These tracks were analyzed using historical chronologies, ship data, and other “regional literature”. / Department of Geography

The aim of this research is to study the formation mechanism of Barrier Layers (BL) in the western tropical Atlantic and their influence on the tropical Atlantic climate at both short and long timescales. Many Coupled General Circulation Models (CGCMs) tend to overestimate the salinity in the Atlantic warm pool or the Northwestern Tropical Atlantic (NWTA) and underestimate the surface salinity in the subtropical salinity maxima region. Most of these models also suffer from a seasurface temperature (SST) bias in the NWTA region, leading to suggestions that the upper ocean salinity stratification may need to be improved in order to improve the BL simulations and thus the SST through BL-SST-Intertropical Convergence Zone (ITCZ) feedbacks. We used a CGCM to perform a set of idealized numerical experiments to understand the sensitivity of the BL and consequently SST in the NWTA region to freshwater flux and hence the upper ocean salinity strati cation. We find that the BL of the western tropical Atlantic is quite sensitive to upper ocean salinity changes in the Amazon River discharge region and the subtropical salinity maxima region. The BL phenomenon is further manifested by the formation of winter temperature inversions in our model simulations. However, in the region of improved BL simulation, the SST response is not statistically significant. SST response to Tropical Cyclones (TCs) is studied for the Atlantic region using a high-resolution coupled regional climate model (CRCM) and observational data sets. The presence of a BL, defined as the layer below the mixed layer that separates the base of the isothermal layer from the base of the isohaline layer, is found to modulate the SST response. The amplitude of TC-induced surface cooling is reduced by more than 35 percent in the presence of a BL, as a consequence of the weak thermal stratification. Furthermore, in locations when the BL exhibits a temperature inversion, TC-induced mixing can result in weak surface warming. BLs considerably reduce the rightward bias for tropical storms, but the effect is less conspicuous for TCs. The enthalpy flux into the atmosphere at the air-sea interface is enhanced by 16 percent and the increase in upper ocean potential energy due to TC-induced mixing is reduced by 25 percent in the presence of BLs. The results from the coupled model are supported by an observational analysis performed using re-analysis data sets, as well as data from Argo floats and TRMM satellite. As previous modeling and observational studies have indicated that the surface cooling caused by TC-induced mixing acts as a negative feedback for its intensity, results from our study suggest that BLs may have potential implications for TC intensity prediction.

The enhanced potential vorticity gradients along the polar jet serve as a wave guide for trapped Rossby waves. These tropopause level, synoptic scale Rossby waves are of primary importance for weather development at the surface. In particular, extreme weather events have been linked to the existence of overlying upper level meridionally elongated filaments of stratospheric (high potential vorticity) air which form during the breaking of these waves. Motivated by the desire to understand the conditions under which these waves are formed and to improve their predictability, the current thesis discusses one excitation mechanism---the potential vorticity anomaly associated with a hurricane approaching the extra-tropics. / Attention is directed toward the adiabatic interaction of the cyclone with the polar jet before the two features meet. The hurricane's ability to excite Rossby waves is verified from observations of past interactions and theoretical study using a mechanistic model with idealized settings. The nature of the interaction between the cyclone and the polar jet is found to be sensitive to parameters such as the cyclone's radius and PV anomaly. Three different regimes have been identified. It is also concluded that the same parameters have influence on the skill of the Rossby wave prediction. The more intense the cyclone is, the harder it is to accurately predict the response of the polar jet.

Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. T.N. Krishnamurti, Florida State University, College of Arts and Sciences, Dept. of Meteorology. Title and description from dissertation home page (viewed Aug. 26, 2004). Includes bibliographical references.

Thesis (Ph.D.)--University of Central Florida, 2009. / Adviser: W. Linwood Jones. Includes bibliographical references (p. 160-163).

This dissertation examines the impact of major hurricanes on changes in GDP for counties in four states – Alabama, Florida, Louisiana, and Texas. The analysis examines the effectiveness of intergovernmental financing for major hurricanes between 2000 and 2014. It also examines whether institutional proximity of the disaster management function to the Governor's Office and the career status of the director affect the speed of recovery from the disaster. The analysis also assesses the impact that a counties's prior experience at dealing with disasters has on the speed of recovery.

Thesis. 1976. M.S.--Massachusetts Institute of Technology. Dept. of Meteorology. / Microfiche copy available in Archives and Science. / Bibliography: leaf 38. / by Alan L. Adams. / M.S.

Thesis. 1978. M.S.--Massachusetts Institute of Technology. Dept. of Meteorology. / Microfiche copy available in Archives and Science. / Bibliography : leaves 64-65. / M.S.

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