Florida is typically considered to be tectonically stable and representative of global eustatic sea level with little evidence for any anomalous local subsidence or uplift during the late Cenozoic. Sea level during most of that time did not significantly rise above the present level. However, paleoshoreline features near the border of northern Florida and southern Georgia have been found to contain marine fossils of Pleistocene age at elevations of between 42 and 49 m above mean sea level, suggesting that some mechanism of epeirogenic uplift has affected the area. A possible cause of uplift during the late Cenozoic is mass removal from the Florida carbonate platform via karst-related groundwater dissolution. Calculations carried out as a part of this study, using measurements of dissolved carbonate in Florida's first- and second-magnitude springs, shows that the karst area of central and north Florida is losing a minimum of 4.8 x 105 m3 /yr of limestone. This carbonate mass loss is equivalent to an approximate thickness of 1 meter of limestone every 160,000 years. The impact of long-term carbonate dissolution and mass loss from the Florida platform has led to isostatic uplift of at least 9 m and as much 58 m since the beginning of the Quaternary (~1.6 Ma). These results were obtained using the measured mass loss rate and calculation of the isostatic response to unloading of the Florida platform. Isostatic uplift due to dissolution of the Florida platform would at least in part explain the occurrence of Plio-Pleistocene marine fossils at elevations significantly higher than sea levels are known to have been during that time. / A Thesis submitted to the Department of Geological Sciences in partial fulfillment of the requirements for the degree of Master of Science. / Degree Awarded: Summer Semester, 2006. / Date of Defense: April 25, 2006. / Springs, Karst / Includes bibliographical references. / Joseph F. Donoghue, Professor Directing Thesis; Sergio Fagherazzi, Committee Member; Jennifer E. Georgen, Committee Member; Sherwood W. Wise, Committee Member.

In the western North Pacific basin, several agencies archive "best track" data of tropical cyclones. The Joint Typhoon Warning Center (JTWC) in Hawaii is responsible for the issuance of tropical cyclone warnings for United States Department of Defense interests and has a record of tropical cyclones extending back to 1945. The Japanese Meteorological Agency (JMA) is the World Meteorological Organization (WMO) official Regional Specialized Meteorological Center (RSMC) for the western North Pacific basin and has best track tropical cyclone data extending back to 1951. The Shanghai Typhoon Institute (STI) of the Chinese Meteorological Administration and the Hong Kong Observatory (HKO) of the Government of the Hong Kong Special Administrative Region also have 6-hourly tropical cyclone data records from 1949 and 1961, respectively. Western North Pacific (WNP) data sets are investigated in order to quantify ambiguities in position and intensity estimates among the forecast institutions through the development of a unified Superset. Ambiguities among the two primary warning centers (JMA and JTWC) are presented in the context of a changing observation network, observational tools, and analysis techniques since the beginning of tropical cyclone records. Mean differences in position estimates are found between the two centers on the order of 60 km prior to the introduction of meteorological satellites in 1961 and near 50 km following the deactivation of aircraft reconnaissance in 1987. Results show a step function change among intensity in JTWC and JMA best track data from 1989 to 1990 due to varying applications of the Dvorak intensity estimation technique. Parsing best track data into landfall subsets does not ameliorate interagency differences in position or intensity estimates. Additionally, analyses from Superset data call into question the veracity of JTWC best track data during the period from 1995-1999. The applicability of adopting an individual data set in discerning long term climate trends is examined in light of these differences. Past efforts to analyze, assemble, and maintain a complete, reliable best track tropical cyclone data set for the WNP are discussed among topical methods of incorporating the Superset within a basin-wide re-analysis. / A Thesis Submitted to the Department of Meteorology in Partial Fulfillment of the Requirements for the Degree of Master of Science. / Spring Semester, 2009. / November 26, 2008. / Climate Change, Global Warming, Climate, Observation, Best Track, Superset, Western North Pacific, Pacific, Tropical Cyclone, HKO, Hong Kong Observatory, STI, Shanghai Typhoon Institute, JMA, Japanese Meteorological Agency, JTWC, Joint Typhoon Warning Center, Typhoon, Reconnaissance, Dvorak / Includes bibliographical references. / James J. O’Brien, Professor Directing Thesis; Jon E. Ahlquist, Committee Member; Mark A. Bourassa, Committee Member; Robert E. Hart, Committee Member.

A new objective technique is used to analyze monthly mean gridded fields of air and sea temperature, scalar and vector wind, specific humidity, sensible and latent heat flux, and wind stress over the Indian Ocean. A variational method produces a 1°x1° gridded product of surface turbulent fluxes and the variables needed to calculate these fluxes. The surface turbulent fluxes are forced to be physically consistent with the other variables. The variational method incorporates a state of the art flux model, which should reduce regional biases in heat and moisture fluxes. The time period is January 1982 to December 2003. The wind vectors are validated through comparison to monthly scatterometer winds. Empirical orthogonal function (EOF) analyses of the annual cycle emphasize significant modes of variability in the Indian Ocean. The dominant monsoon reversal and its connection with the southeast trades are linked in eigenmodes one and two of the surface fluxes. The third eigenmode of latent and sensible heat flux reveal a structure similar to the Indian Ocean Dipole (IOD) mode. The variability in surface fluxes associated with the monsoons and IOD are discussed. September-October-November composites of the surface fluxes during the 1997 positive IOD event and the 1983 negative IOD event are examined. The composites illustrate characteristics of fluxes during different IOD phases. / A Thesis Submitted to the Department of Meteorology in Partial Fulfillment of the Requirements for the Degree of Master of Science. / Spring Semester, 2006. / November 30, 2005. / Indian Ocean Dipole Mode, Indian Ocean, Objective Method, Surface Turbulent Fluxes, Monsoon, Gridded Product / Includes bibliographical references. / Mark A. Bourassa, Professor Directing Thesis; Carol A. Clayson, Committee Member; James J. O’Brien, Committee Member.

Changes in the amount of dissolved oxygen concentration in the Sea of Japan (SOJ) over a number of years have been hypothesized to be due to the amount and depth of deep convection in this region. The first observations of the changes in oxygen concentration at depth due to deep convection in near-real time occurred during a recent Office of Naval Research-sponsored program, which included both ship tracks and floating buoy measurements. In general the process of deep convection has been divided into three general phases: preconditioning, deep convection, and lateral exchange and spreading (restratification). In this work we evaluate buoy and ship data between August of 1999 and August 2001 in order to understand the role and types of preconditioning evident in the SOJ, and compare with results from other regions with deep convection such as the Labrador Sea, the Mediterranean Sea, and the Green land Sea. Several aspects of preconditioning relative to other locations that we evaluated include the existence of a cyclonic gyre, doming of the isopycnals, and changes in mixed layer depth. The focus of our analysis was a region located south of the Peter the Great Bay and mainly north of the subpolar front (from 40.5°N to 42.5°N and from 131.0°E to 134.0° E). This has been one of the historically-designated regions of open ocean deep convection, due to its proximity to cold air outbreaks channeled through the opening in the mounts near Vladivostok. This is also the location of deep convection during the 1999 – 2001 time period from both observations and model simulations. The major findings of this study were that the surface cyclonic circulation has a primary role in preconditioning by transporting water transformed along the Siberian coast into the eastern portion of the deep convection region. We found that doming of isopycnals is not an important contributor to either preconditioning or deep convection, with a general uplifting of isopycnals of at most 100 meters. The evolution of the mixed layer properties and depth was found to be an important part of the preconditioning in SOJ. Changes in both temperature and salinity are affected by surface forcings (particularly in autumn) and by advection. / A Thesis Submitted to the Department of Oceanography in Partial Fulfillment of the Requirements for the Degree of Master of Sciences. / Fall Semester, 2006. / July 14, 2006. / Sea Of Japan, Deep Convection, Preconditioning, JES / Includes bibliographical references. / Carol Anne Clayson, Professor Directing Thesis; Jeff Chanton, Outside Committee Member; William K. Dewar, Committee Member; Doron Nof, Committee Member.

Stable isotopes of oxygen, carbon and nitrogen were used to understand the ecological changes induced by human activities. The existing method developed by McLaughlin et al. (2004) for determination of the oxygen isotopic composition of dissolved phosphate (DIP) is not directly applicable to organic-rich waters in the Florida Everglades and produced Ag3PO4 precipitates contaminated by high amounts of organic matter. A series of laboratory tests was conducted to reduce the amount of organic contaminant in Ag3PO4 prepared from organic-rich DIP samples and to improve the accuracy of oxygen isotopic analysis of DIP. The improved method reduces the organic contamination in the final Ag3PO4 precipitates by more than 10 fold (from >20% C to ~2% C) compared to the previous method and can be used to accurately determine the oxygen isotopic composition of DIP in organic rich aquatic ecosystems if the oxygen isotopic difference between the DIP and dissolved organic matter is less than 13‰.20% C to ~2% C) compared to the previous method and can be used to accurately determine the oxygen isotopic composition of DIP in organic rich aquatic ecosystems if the oxygen isotopic difference between the DIP and dissolved organic matter is less than 13‰. The improved method was used to examine the oxygen isotopic systematics of DIP and to identify P sources and recycling in the Everglades. Our data reveal seasonal variations in the &delta18O of DIP, with lower values in the summer and higher values in the winter. Our results show that the &delta18O values of DIP collected from the Everglades National Park are in equilibrium with environmental water. This indicates that phosphorus (P) is quickly recycled in areas with low P concentrations. However, most DIP samples collected from areas impacted by high P loading are not in oxygen isotopic equilibrium with water, suggesting that biological cycling of P is not fast enough to erase the "fertilizer" &delta18O signature in the DIP pool in areas with high P levels. Using a two-endmember (i.e., fertilizer P and biologically recycled P) mixing model, we estimated that less than 57.5% of the DIP was derived from fertilizer. The &delta18O of total P (&delta18OTP) in sediments suggests at least three P resources: organic P with depleted 18O, fertilizer P with &delta18O values of ~23.7‰, and bacteria-processed P with &delta18O of ~16 to 24‰ at 20 to 30°C. Our data also show that the sediment P is dominated by organic P. The &delta18O of DIP displayed significant negative correlations with precipitation and evapotraspiration, underscoring the importance of hydrological factors in controlling the P cycle. Stable isotopes of carbon and nitrogen were used to trace the source of carbon and nutrients and to investigate the food web structure in Missouri River. Our data show that all the fish depend on the same carbon source and there exists significant dietary overlap between the invasive Asian carps and the native filter-feeding fishes. The similarity of &delta13C values of particulate organic matter and the fish muscle tissue indicate that the food base of the filter-feeding fishes was particulate organic matter in the water column. Bighead carp, the hybrids, gizzard shad, silver carp and bigmouth buffalo have trophic positions of 2.9, 2.9, 3, 2.1 and 2.6, respectively. Bighead carp and the hybrids compete with paddlefish for zooplankton and silver carp compete with gizzard shad for algae and detritus. Understanding the competitions between the invaders and native species can help policy makers and ecosystem managers to better manage the aquatic system. / A Dissertation Submitted to the Department of Geological Sciences in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy. / Summer Semester, 2009. / April 29, 2009. / Oxygen, Phosphorus, Nitrogen, Carbon, Isotope / Includes bibliographical references. / Yang Wang, Professor Directing Dissertation; Jeffrey Chanton, Outside Committee Member; Xiaolong Bill Hu, Committee Member; A. Leroy Odom, Committee Member.

Rapid intensity changes in hurricanes have been the focus of many publications. Understanding how and why these storms intensify has been the goal of many meteorologists over the last few years. This study explores the energetics of Psi-Chi interactions in modeled hurricanes of rapidly changing intensity. The energy exchanged within the storm as the flow changes from divergent to rotational is known as Psi-Chi interactions. Processes associated with latent heant and sensible heat exchanges are important when it comes to identifying changes in hurricane intensity. Understanding this interaction with the environment is crucial to understanding how the intensity changes. Model data derived from the fifth generation model from NCAR/Penn State known as the MM5 is used to calculate each term within the Psi-Chi equation. Each term is then calculated within the storm and its maximum values as well as location of maximum values within the storm are noted. The maximum value of each term and location of each term allows for an investigation of a connection between the energy exchange of the storm and its intensity. The maximum values of the terms of Psi-Chi interactions are also compared to the model intensity of each storm. Based on the comparison of model intensity and maximum term values there appears to be a strong relationship between the two (correlation values near r = 0.87), although further study is needed to determine if this simultaneous relationship can be extended to a lagged relationship to provide predictive value to forecasters. / A Thesis Submitted to the Department of Earth, Ocean and Atmospheric Science in Partial Fulfillment of the Requirements for the Degree of Master of Science. / Summer Semester, 2011. / March 7, 2011. / Hurricane, Psi Chi, Intensity / Includes bibliographical references. / T. N. Krishnamurti, Professor Directing Thesis; Robert E. Hart, Committee Member; Vasubandhu Misra, Committee Member.

The lack of satellite imagery prior to 1966 and limited aircraft reconnaissance has led to an indefinite number of tropical cyclones (TCs) in the Atlantic Basin remaining undetected by traditional surface observational networks. As a result, these cyclones were not identified by operational forecasting centers like the National Hurricane Center and are not a part of the consensus Atlantic TC climatology. While previous research suggests that this historical undersampling exists, there is considerable disagreement as to its true magnitude. However, it is widely accepted that these "missing storms" have led to difficulties in interpreting long-term trends in TC activity, adding uncertainty to the dialogues over the nature, role, and existence of the Atlantic Multi-decadal Oscillation and the possible influence of climate change on TC activity, among many others. This research seeks to add information to Atlantic Basin TC climatology by developing a scheme to identify previously unknown potential cyclones in the pre-satellite era. The technique utilizes advances in global reanalysis methods to identify candidate events within certain probabilistic bounds in order to improve existing TC Best-Track reanalysis efforts. Briefly, a series of thermodynamic proxies of TC passage in the NOAA/CIRES 20th Century Reanalysis dataset is first constructed. Signatures in these metrics that are of similar amplitude and morphology to known TCs but do not correspond to known Best-Track cyclones are identified within the reanalysis solution for the test hurricane seasons of 1951 through 1958. Synoptic verification of these candidate events using historical surface observation datasets sorts the events into three broad confidence bins. The most common outcome of the observational verification process is that the candidate event does not represent a credible possible addition to BT climatology. However, a small but significant number of the candidate events were found to present highly compelling cases for further examination by ongoing TC climatology revision efforts and may eventually warrant addition to the Best-Track database. Several of these candidate events, representing a broad range of possible uses of the technique, are presented in detailed case studies. Additionally, application of the reanalysis-based methodology to the Eastern Pacific Basin demonstrates promise for use in other TC basins around the world. In general, results suggest that future work extending the technique developed in this research may potentially lead to a more complete climatological record of global TC incidence and an improved understanding of long-term trends in activity. / A Thesis Submitted to the Department of Earth, Ocean, and Atmospheric Science in Partial Fulfillment of the Requirements for the Degree of Master of Science. / Spring Semester, 2011. / March 28, 2011. / Tropical Cyclones, Climatology, Reanalysis / Includes bibliographical references. / Robert Hart, Professor Directing Thesis; Carol Anne Clayson, Committee Member; Henry Fuelberg, Committee Member.

The low-frequency signals (LFS) of climate variables such as temperature and pressure often contain variability as a result of the nonlinear and non-stationary nature of Earth's climate system. Occasionally, as in the case of the North Pacific climate regime shift of the mid-1970s, this variability appears in the form of an abrupt shift in climate states. Because such variability can have large impacts on agriculture, wildfire frequency/intensity, and ecological systems, it is important to pursue a more complete understanding of low frequency climate interactions. Previously, techniques such as fourier, windowed fourier, and wavelet analyses were used to extract the LFS. However, these techniques rely on an assumption of linearity, and thus when applied to nonlinear climate data, can potentially cloud the physical meaning of the extracted LFS. In this study a recently developed adaptive and temporally local analysis method—ensemble empirical mode decomposition (EEMD)—is applied to extract the LFS from observed daily minimum temperature data. The analysis uses data from 115 weather stations scattered throughout North Carolina, South Carolina, Georgia, Alabama, and Florida for the period from 1955 through 2007. An EOF analysis of the minimum temperature LFS reveals a large drop in the first PC time series in the mid-1970s. Further EOF-based analysis of the low-frequency variability leads to different interpretations of the characteristics of surface temperature variability. Most notably, the widely recognized shift of low-frequency variability around the mid-1970s can be alternatively interpreted in the Southeastern United States as phase coincidence between individual quasi-oscillatory components of interannual to decadal timescales. / A Thesis Submitted to the Department of Earth Ocean and Atmospheric Science in Partial Fulfillment of the Requirements for the Degree of Master of Science. / Spring Semester, 2011. / March 21, 2011. / Low-frequency variability, Climate variability, Climate regime / Includes bibliographical references. / Zhaohua Wu, Professor Directing Thesis; Vasu Misra, Committee Member; Philip Sura, Committee Member.

Carbon isotopes were used as tracers in the Florida Everglades to investigate the sources and sinks of dissolved organic carbon in natural and constructed wetlands and provide a way to monitor ecosystem restoration efforts. Stable carbon isotopes were used to determine the source of DOC and POC, and in a basic mass balance model to calculate turnover times of DOC in small constructed wetland cells. Radiocarbon was used to distinguish "old" DOC derived from historic peats from "new" DOC derived from modern primary production. Our study suggests that Ä14C measurements can be a useful indicator of the progress of ecosystem restoration in the Everglades. The oxygen isotope of phosphate (P) can also serve as an isotopic tracer in wetlands. Initial method development to use the oxygen isotope of phosphate extracted from natural waters is presented here. Preliminary data indicates that microbial recycling is a major means by which P stays in the water column despite reducing anthropogenic contributions. Stable carbon isotopes were also used to quantify the percent of methane oxidized within Tallahassee landfill soils. Carbon isotope and oxidation data collected over almost 9 months of monitoring methane emissions from landfill surfaces with and without a "biocover" is examined. These measurements, combined with measurements of methane flux, can help monitor the efficiency of various treatments in reducing methane emissions to the atmosphere by enhancing oxidation of methane by methanogenic bacteria. The presence or absence of DOC in the water column can determine whether trace metals will be present as a nutrient or as a toxicant. A novel method coupling capillary electrophoresis with ICP-MS was used to separate metal species and calculate binding constants of rare earth elements and Th, Hf, and Zr with humic substances at a range of pH and ionic strength of 0.1. Equilibrium dialysis ligand exchange was performed to validate the CE-ICP-MS method. Conditional stability constants of tetravalent metal-HA complexes are several orders of magnitude higher than lanthanide-HA complexes. Because thorium is often used as a proxy for the tetravalent actinides, Th-HA binding constants are useful in the study of sequestration of actinides in nuclear repository settings. / A Dissertation Submitted to the Department of Geological Sciences in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy. / Summer Semester, 2005. / April 28, 2004. / Metal speciation, Humic acid, Thorium, Capillary electrophoresis, CE-ICP-MS, Landfill Methane, Phosphorus, Everglades, Carbon isotopes / Includes bibliographical references. / Yang Wang, Professor Co-Directing Dissertation; Vincent J.M. Salters, Professor Co-Directing Dissertation; Jeffrey Chanton, Outside Committee Member; A. Leroy Odom, Committee Member.

Modern (farmed) calcite in Hollow Ridge Cave, Marianna, FL, USA was cultivated seasonally and analyzed for isotopic composition (δ18O and δ13C). Simultaneous in situ cave-air chemistry, drip water composition, and micrometeorology were continuously monitored to unravel the connection between the depositional timing and isotopic composition of calcite and ventilation-driven changes in cave-air CO2. Multi-year collection of soil gas, atmospheric and cave-air CO2 samples and drip waters allow the prediction of dripwater calcite saturation state, and thus speleothem precipitation, as a function of cave-air pCO2. This study demonstrates that high summer-time cave air pCO2 inhibits calcite growth, and that deep interior Hollow Ridge Cave speleothems preserve winter-time paleoclimate signals. This work also demonstrates the existence of a relationship between ventilation, evaporation and rapid CO2 loss on modern Hollow Ridge Cave calcite. Furthermore oxygen isotopic composition of Hollow Ridge calcite exhibits a constant positive offset from both the O'Neil et al. (1969) and Kim & O'Neil (1997) inorganic calcite temperature equations, allowing the construction of a new temperature equation for speleothem calcite that describes both temperature and ventilation fractionation effects on speleothem precipitation. This study illustrates the value of investigating site-specific drip water and cave-air chemistry before making speleothem-based interpretations of paleoclimate. This study has also provided a valuable link between rainfall, epikarst saturation state, and modern drip water residence time and x/Ca element partitioning in both water and calcite. It was observed that each site of calcite growth inside HRC has a unique chemistry in terms of x/Ca vs. Mg/Ca ratios. The data at each site are representative of a two endmember mixing system; (1) calcite dissolution during wetter epikarst periods, and (2) rainfall dilution. Sites can clearly be chemically grouped which suggests that down-slope hydrology and water residence time partially control the chemistry of drip water at HRC. Distribution coefficients were established for HRC calcite, and by comparing x/Ca vs Mg/Ca in drip waters with x/Ca vs. Mg/Ca in calcite it was determined that Li, Sr, K, U and Si are suitable modern-day solid-phase indicators of the hydrological conditions in the epikarst above HRC. This study also established that Na, Mn and Ba are not suitable standalone paleohydrologic proxies, but may be useful indicators when used together. / A Thesis Submitted to the Department of Oceanography in Partial Fulfillment of the Requirements for the Degree of Master of Science. / Summer Semester, 2010. / May 5, 2010. / Paleoclimate, Speleothem, Cave, Isotopes, Trace Element / Includes bibliographical references. / Philip N. Froelich, Professor Directing Thesis; Yang Wang, Committee Member; Doron Nof, Committee Member; Allan Clarke, Committee Member; Bill Burnett, Committee Member.