Thesis (M. S.)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2009. / Committee Chair: Jean Lynch-Stieglitz; Committee Co-Chair: Emanuele Di Lorenzo; Committee Member: Annalisa Bracco; Committee Member: Robert Black

We investigate the effect of a 120 meter sea level drop on transport through the Caribbean Sea and the Florida Straits during the Last Glacial Maximum (LGM) relative to the present, using the Regional Ocean Modeling System (ROMS). A geostrophic transport estimate for the Florida Straits suggests the LGM Florida Current was weaker than today by one third, inferring a likely decrease in the North Atlantic overturning circulation by 12-15 Sv. A possible impact of a shallower LGM Florida Straits sill depth on the Florida Current has been suggested. Our model results show that the volume transport through the Florida Straits is slightly reduced in a lower sea level model simulation when compared to a control sea level simulation (34.8 ± 2.0 Sv vs. 39.8 ± 2.3 Sv). The difference in transport is of the order of 5 Sv, representing a maximum limit to the LGM flow reduction due to sea level change. Therefore the change in sill depth between the LGM and the present is unlikely to have been a cause of the entire observed flow reduction.

The Gulf Stream current in the Straits is typically dominated by a strong northerly current, associated shear, and eddies. The water column also includes a prominent thermocline and periodically features internal waves centered on the upper or lower edges of the thermocline. Despite numerous previous related studies, there is limited available field data on internal waves in the Straits of Florida. Here, study and analysis of velocity, temperature and conductivity data acquired in the Straits over a period of time are described, in support of identifying presence of internal waves in the flow. A systematic procedure is employed in modifying the universal Garrett- Munk spectrum for internal waves in the open ocean for application to flow in the Straits of Florida. Using this process, identified internal waves are characterized and related velocity fluctuations in the time series are isolated to facilitate consideration of their correlations with simultaneously observed magnetic fields. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

The Straits of Florida has been noted as a potential location for extraction of the kydrokinetic energy of the Florida Current, in view of the strength of the current and its proximity to the shore. ... This research explores the Florida Current as a potential renewable energy source. By utilizing historical data, in situ observations of the Florida Current, and computer model data, the hydrokinetic resource of the Florida Current is characterized both spatially and temporally. Subsequently, based on the geographic variability of the hydrokinetic power and other factors that impact the economy of a hydrokinetic turbine array installation, the ideal locations for turbine array installation within the Florida Current are identified.... Additionally, an interactive tool has been developed in which array parameters are input - including installation location, turbine diameter, turbine cut-in speed, etc. - and array extraction estimates, ideal installation position, and water depth at the installation points are output. As ocean model data is prominently used in this research, a discussion about the limitations of the ocean model data and a method for overcoming these limitations are described. Globally, the distribution of hydrokinetic power intensity is evaluated to identify other currents that have a high hydrokinetic resource. / by Alana E. Smentek-Duerr. / Thesis (Ph.D.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

Swordfish (Xiphias gladius) are increasingly sought after by recreational anglers around the world. The Florida Straits in particular are an important breeding and nursery area for North Atlantic swordfish, as well as for being historical fishing grounds for both recreational and commercial swordfish fisheries. The recreational fishery for swordfish in southeastern Florida is categorized into two historical periods. The first period started in 1977 and consists of the first tournaments in the area to specifically target swordfish. Despite high initial catches, low catch numbers forced the tournament fishery to close in 1983. During the second period of the fishery (starting in 2000 to today) the tournament fishery for swordfish has reemerged. Data from a total of 98 swordfish tournaments (17 historic, 81 current) have been collected. For comparison, information has been gathered from 72 istiophorid billfish tournaments within the modern (second) period. These data were gathered from tournament directors, websites, and personal communication with participants of the tournaments. The tournaments studied took place on the east coast of Florida from Stuart south to Key West, with a majority being held between Lighthouse Point and Islamorada in the Florida Keys. Although participation correlates to the number of catches, catch per hour (CPH) remains on a slow although not significant decrease over time. The entry fees for these modern period swordfish tournaments range from $200-600, while those for the more exclusive billfish tournaments are tenfold swordfish entry costs. Similarly, awarded prize monies of billfish tournaments are tenfold and significantly larger than prize monies for swordfish tournaments. The average weight of landed swordfish has shifted slightly in both the historic and the modern periods. Despite the oscillation of catch numbers throughout the two time periods, the weight of caught swordfish remained roughly the same. This may be from the minimum length restrictions implemented in the modern time period, a regulation which did not exist during the tournaments of the historic period.

Previous studies showed that sea surface salinity (SSS) in the Florida Straits as well as Florida Current transport covaried with changes in North Atlantic climate over the past two millennia. However, little is known about earlier Holocene variability in the Florida Straits. Here, we combine Mg/Ca-paleothermometry and stable oxygen isotope measurements on the planktonic foraminifera Globigerinoides ruber (white variety) from Florida Straits sediment core KNR166-2 JPC 51 (24 degrees 24.70? N, 83 degrees 13.14?W, 198m deep) to reconstruct a high-resolution (~30 yr/sample) early to mid Holocene record of sea surface temperature and delta18OSW (a proxy for SSS) variability. We also measured Ba/Ca ratios in the same shell material as a proxy for riverine input into the Gulf of Mexico over the same time interval. After removing the influence of global delta18OSW change due to continental ice volume variability, we propose that early Holocene SSS enrichments were caused by increased evaporation/precipitation ratios in the Florida Straits associated with periods of reduced solar output, increased ice rafted debris in the North Atlantic and the development of more permanent El Nino-like conditions in the eastern equatorial Pacific. When considered with previous high-resolution reconstructions of early Holocene tropical atmospheric circulation changes, our results provide evidence that solar output variability over the Holocene had a significant impact on the global tropical hydrologic cycle over the last 10,000 years.