Thesis (Ph. D.)--Texas State University-San Marcos, 2006. / Vita. Appendices: leaves 119-142. Includes bibliographical references (leaves 143-147).

Thesis (Ph. D.)--Texas State University-San Marcos, 2006. / Vita. Appendices: leaves 119-142. Includes bibliographical references (leaves 143-147).

Accurate predictions and understanding of littoral and coastal wave conditions are of major importance to military operations and civilian coastal zone management. Although WaveWatchIII (WW3) is used by many operational forecasting centers around the world, there is a lack of field studies to evaluate its accuracy in regional applications and under extreme conditions, such as Hurricanes. Data from seven National Data Buoy Center (NDBC) buoys in the Gulf of Mexico, together with an array of pressure and pressure-velocity sensors deployed on the Florida Panhandle shelf during the Office of Naval Research (ONR) SAX04 experiment, were used to test WW3 predictions of extreme waves generated by Hurricane Ivan. The model predicts large differences between wave conditions on the left and right sides of the hurricane track owing to the difference in "dwell time" between wave propagating against and with the storm. Analysis reveals a tendency to predict smaller wave heights and later arrival of hurricane swell than is observed. Additionally, the default operational setting for dissipation by bottom friction yields too much dissipation on the continental shelf. Overall, the agreement between observations and model predictions is reasonable.

Forecast hurricane tracks using a multi-model ensemble that is comprised by linearly combining the individual model forecasts have greatly reduced the average forecast errors when compared to individual dynamic model forecast errors. In this experiment, a complex adaptive system, the Tropical Agent Forecaster (TAF), is created to fashion a 'smart' ensemble forecast. The TAF uses autonomous agents to assess the historical performance of individual models and model combinations, called predictors, and weights them based on their average error compared to the best track information. Agents continually monitor themselves and determine which predictors, for the life of the storm, perform the best in terms of the distance between forecast and best-track positions. A TAF forecast is developed using a linear combination of the highest weighted predictors. When applied to the 2004 Atlantic hurricane season, the TAF system with a requirement to contain a minimum of three predictors, consistently outperformed, although not statistically significant, the CONU forecast at 72 and 96 hours for a homogeneous data set. At 120 hours, the TAF system significantly decreased the average forecast errors when compared to the CONU.

, for the life of the storm, perform the best in terms of the distance between forecast and best-track positions. A TAF forecast is developed using a linear combination of the highest weighted predictors. When applied to the 2004 Atlantic hurricane season, the TAF system with a requirement to contain a minimum of three predictors, consistently outperformed, although not statistically significant, the CONU forecast at 72 and 96 hours for a homogeneous data set. At 120 hours, the TAF system significantly decreased the average forecast errors when compared to the CONU. The multi-agent (MAS) system approach opens the door for statistically significant forecast improvement. / US Navy (USN) author.

The Compact Airborne Spectrographic Imager (CASI) and the satellite Moderate Resolution Imaging Spectroradiometer (MODIS) provide detailed information about the environment U.S. Naval forces choose to operate in. In recent years environmental conditions have been a driving factor in preventing the detection of underwater objects like mines. Suspended sediments are an environmental condition of interest. Remote sensors provide an opportunity to detect suspended sediments in a region prior to the commencement of operations and better prepare the force while reducing time required to complete operations. Monthly data sets collected using MODIS, from February 2005 to February 2006 show variations in weather patterns in the Mississippi Bight that cause the persistent presence of suspended sediments in certain areas of the Mississippi Bight. Major storm events such as hurricanes alter the location that suspended sediments persist in this region during the hurricane season. MODIS with 250m-pixel resolution is capable of detecting large-scale suspended sediment plumes while CASI with 1m-pixel resolution is capable of detecting very fine suspended sediment filaments as well as providing early warning of possible mine locations. As the mine warfare fleet diminishes in size, CASI and MODIS coupled with current sensors may provide an increase in detection capability while reducing the workload of mine detection ships. Continued research and study of suspended sediment transport during hurricane seasons may provide more information about how the environment changes.

In recent times, communities and structures along the Gulf of Mexico have experienced the destructive and devastating impact of hurricane surges and waves. While the impacts of surges have been studied, there exists a need for (1) the understanding of open-coast and bay environment hurricane wave conditions and (2) expedient prediction, for rapid evaluation, of wave hazards as a function of hurricane parameters. This thesis presents the coupled ADCIRC-SWAN numerical model results of wave height sensitivity based on the investigation of several hurricane parameters. Also presented is the development of parameterized maximum significant wave height models. These are determined by incorporating three forms of an equivalent fetch into (1) dimensionless best-fit equations and (2) Shoreline Protection Manual (SPM) method. Computational results indicate that for a range of simulated hurricane parameters, a wide range of spatial and temporal characteristics, for the significant wave height, exists. The location of hurricane landfall results in a significant difference in the wave height at specified points. Additionally, the variation in central pressures, radius sizes and forward speeds leads to elevated surge levels that contribute to wave generation. Furthermore, the time evolution trend of the generation of the significant wave height is found to be unique to its geographic location. In the development of parameterized maximum significant wave height models, the dimensionless best-fit equation approach indicates how strongly the various forms of the equivalent fetch and the bathymetric depth ultimately determines the predicted maximum significant wave height. This approach yielded RMSE that range between 0.52m – 0.68m. Additionally, the accuracy for this approach varied greatly as the highest scatter index was 0.28 for the open-coast points and 0.37 for the bay points. The SPM approach gives an indication of how strongly the functional form of the equivalent fetch determines the predicted maximum significant wave height. When compared to the dimensionless approach, this method produced a lower RMSE of 0.37m and a greater accuracy for the scatter index of 0.23 for the open-coast points and 0.31 for the bay points.

Thesis (M.S.)--University of Missouri-Columbia, 2008. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 22, 2008) Includes bibliographical references.

No description available.

Thesis (Ph. D.)--State University of New York at Binghamton, Department of Economics, 2007. / Includes bibliographical references.