Dissolved organic matter (DOM) is well known for its strong binding capacity for trace metals. In order to better predict the role of DOM in the speciation and transport of trace metals in the environment capillary electrophoresis (CE), a molecular separation technique, was coupled to a Sector Field Inductively Coupled Plasma Mass Spectrometer (SF-ICP-MS). The combination of these two techniques allows for the study of non-labile metal speciation in aquatic samples. An extensive theoretical analysis of metal-ligand separations on the molecular scale of a CE experiment was combined with numerical simulations and experimental tests to assure accurate quantitative results. It was found that the susceptibility of metal-ligand complexes to dissociation during a CE separation can be conveniently captured with a theoretical approximation of complex half-life. Complex half-life, thus is proposed to serve as a tool for assessing the likeliness of quantitative artifacts in CE-ICP-MS. By separating lanthanide complexes with EDTA and Humic Acids (i.e. strong stable ligand competition) we have been able to determine equilibrium binding constants for all 14 stable rare earth elements (REEs), Sc and Y with Suwannee river fulvic acid (SRFA) and Leonardite humic acid (LHA) at near environmental conditions (pH 6-9, 0.01 – 0.01 mol.L-1 NaNO3, 100 nmol.L-1 Ln, 10 mg.L-1 HS). Conditional binding constants for LnHS (Kc) were found to increase gradually by 2-3 orders of magnitude from La to Lu. This increasing relative affinity reflects the lanthanide contraction, a basic chemical property of the REEs related to the gradual decrease in ionic radius from La to Lu. LogKc values were found to gradually increase with increasing pH and decrease with increasing ionic strength. Additionally, LHA logKc's were on average 1.5 log units higher than SRFA logKc's with a total range of 9.0 / A Dissertation submitted to the Department of Geological Sciences in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2003. / October 31, 2003. / Lanthanides, Binding constant, Humic substances, ICP-MS / Includes bibliographical references. / Vincent J. M. Salters, Professor Directing Dissertation; William M. Landing, Outside Committee Member; William T. Cooper, Outside Committee Member; Louis Claude Brunel, Outside Committee Member; A. Leroy Odom, Committee Member; Yang Wang, Committee Member.

There is an operational need for accurate tropical cyclone (TC) genesis forecasts. Global numerical models are an important genesis guidance tool, but each model has biases. Further, the interpretation of when genesis occurs in a model forecast field can be subjective. Thus, this study seeks to create an automated, objective, statistical-dynamical TC genesis guidance tool for the North Atlantic and eastern North Pacific basins based on output from the CMC, GFS, and UKMET global models. Another goal is to determine how well important genesis processes in global models agree with those theoretically proposed. This research also attempts to identify the characteristics of successful and failed genesis forecasts. First, historical global model forecasts of TC genesis over the past decade are verified. Using this genesis forecast archive, univariable logistic regression equations are created to reveal the statistical relationships between relevant variables and genesis probability. These statistical relationships are compared to theoretical relationships between atmospheric variables and TC genesis. Results show several expected and counterintuitive statistical relationships, with some disagreement among the models. Multiple logistic regression equations then are developed to provide probabilistic genesis forecasts. Separate equations are developed for each global model, basin, and forecast window. Additionally, a consensus regression equation is developed. These equations are tested operationally during the 2014 hurricane season. Verification of the independent data indicates generally well-calibrated guidance. Homogeneous comparisons of the consensus regression equation and National Hurricane Center Tropical Weather Outlook genesis probabilities are presented. Case studies and composite analyses are conducted to gain further insight. Case studies from the following categories are selected: (1) African Easterly Wave genesis over the Main Development Region; (2) genesis from stalled frontal boundaries; (3) genesis via tropical transition; and (4) genesis over the Gulf of Mexico. Hit, miss, and false alarm events are compared. Storm centered composite analyses also are constructed to examine differences in the environments between hit and false alarm forecasts. Separate composites are made for the eastern Main Development Region (where the GFS false alarm rate is greatest) and the remainder of the North Atlantic basin. Statistically significant differences between hit and false alarm cases are found for all variables analyzed with various areal extents. Results from the case studies and composite analyses will help guide new predictors to test for inclusion into the multiple logistic regression equations. Additionally, the case study of Sean (2011) suggests that changes to the TC identification algorithm are needed to better detect subtropical to tropical transition. Real-time guidance products based on the logistic regression equations are being evaluated by hurricane specialists at the National Hurricane Center. It is possible that the products will be selected for operational implementation pending further testing and evaluation during 2015. / A Dissertation submitted to the Department of Earth, Ocean, and Atmospheric Science in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester 2015. / June 1, 2015. / forecasting, genesis, global models, hurricane, tropical cyclone, verification / Includes bibliographical references. / Henry E. Fuelberg, Professor Co-Directing Dissertation; Robert E. Hart, Professor Co-Directing Dissertation; Kristine C. Harper, University Representative; Jeffrey M. Chagnon, Committee Member; Guosheng Liu, Committee Member.

Integrated kinetic energy (IKE) is a recently developed metric that approximates the destructive potential of a tropical cyclone by assessing the size and strength of its wind field. Despite the potential usefulness of the IKE metric, there are few, if any, operational tools that are specifically designed to forecast IKE in real-time. Therefore, IKE and tropical cyclone structure are analyzed within historical Atlantic tropical cyclones from the past two decades in order to develop an understanding of the environmental and internal storm-driven processes that govern IKE variability. This analysis concurs with past research that IKE growth and decay is influenced by both traditional tropical cyclone development mechanisms and by other features such as extratropical transition and trough interactions. Using this framework, a series of statistical prediction tools are created in an effort to project IKE in Atlantic tropical cyclones from a series of relevant normalized input parameters. The resulting IKE prediction schemes are titled the "Statistical Prediction of Integrated Kinetic Energy (SPIKE)". The first version of SPIKE utilizes simple linear regression to project historical IKE quantities in a perfect prognostic mode for all storms between 1990 and 2011. This primitive model acts as a proof of concept, revealing that IKE can be skillfully forecasted relative to persistence out to 72 hours by even the simplest of statistical models if given accurate estimates of various metrics measured throughout the storm and its environment. The proof-of-concept version of SPIKE is improved upon in its second version, SPIKE2, by incorporating a more sophisticated system of adaptive statistical models. A system of artificial neural networks replaces the linear regression model to better capture the nonlinear relationships in the TC-environment system. In a perfect prognostic approach with analyzed input parameters, the neural networks outperform the linear models in nearly every measurable way. The system of neural networks is also more versatile, as it is capable of producing both deterministic and probabilistic tools. Overall, the results from these perfect prognostic exercises suggest that SPIKE2 has a high potential skill level relative to persistence and several other benchmarks. Finally, in an effort to assess its real-time performance, the SPIKE2 forecasting system is run in a mock-operational hindcast mode for the 1990 to 2011 North Atlantic hurricane seasons. Hindcasts of IKE are produced in this manner by running the neural networks with hindcasted input parameters from NOAA's second generation Global Ensemble Forecast System reforecast dataset. Ultimately, the results of the hindcast exercises indicate that the neural network system is capable of skillfully forecasting IKE in an operational setting at a level significantly higher than climatology and persistence. Ultimately, forecasts of IKE from these neural networks could potentially be an asset for operational meteorologists that would complement existing forecast tools in an effort to better assess the damage potential of landfalling tropical cyclones, particularly with regards to storm surge damage. / A Dissertation submitted to the Department of Earth, Ocean and Atmospheric Science in partial fulfillment of the Doctor of Philosophy. / Spring Semester, 2015. / March 19, 2015. / Atlantic Hurricanes, Integrated Kinetic Energy, Statistical Prediction, Tropical Cyclone Structure, Tropical Meteorology / Includes bibliographical references. / Vasubandhu Misra, Professor Directing Dissertation; Ming Ye, University Representative; Robert E. Hart, Committee Member; Philip Sura, Committee Member; Allan J. Clarke, Committee Member; Mark D. Powell, Committee Member.

Since 1980, a new type of ENSO, i.e., central Pacific (CP) ENSO, where sea surface temperature anomalies (SSTAs) are mainly located in the equatorial central Pacific, has been frequently observed. Several studies have documented and predicted a higher occurrence ratio of CP ENSO to eastern Pacific (EP) ENSO, where SSTAs mainly occur in the equatorial eastern Pacific, in a warming climate. Most studies centered on the difference between CP and EP ENSO have used traditional analysis methods, such as PCA/EOF analysis and regression, to define or differentiate the aforementioned two types of ENSO. However, the results obtained using these methods can only reveal accumulated spatial information which contributed most to the variance of the data, which is the usually the spatial information during the mature (peak) stage of ENSO; this spatial information is a static pattern and is not able to reveal sequential development of ENSO, which should be crucial for physical interpretations. In addition, although this spatial information in generally true for the entire temporal span, it is not necessarily true for any subperiods and thus not able to reveal any potential characteristic change of ENSO over time. In this study, an alternative Niño 3.4 index is defined to reflect only the interannual variability of equatorial Pacific SSTAs. Using this alternative index, we identify 28 El Niño events and 31 La Niña events. Then, we employ a newly developed analysis method, i.e., fast multidimensional ensemble empirical mode decomposition (FMEEMD), to extract the interannual spatiotemporal evolution of SSTAs to examine the developments of the identified ENSO events. All events are classified into four types of ENSO based on the interannual evolutions of SSTAs early in the development stage: (1) EP ENSO, (2) eastern-central Pacific (ECP) ENSO, (3) western-central Pacific (WCP) ENSO, and (4) mixed (MIX) ENSO. We apply the same method to analyze surface horizontal wind and thermocline depth data, and phase composite analyses on SSTAs, surface wind anomalies and thermocline depth anomalies are performed for each type of El Niño events. The results show four distinctive evolution patterns; it is found that La Niña events also have similar variation in the evolution patterns. The lower-frequency variability and change (decadal and longer time scales, including secular trend trend) in SSTAs, surface wind anomalies and thermocline depth anomalies are also examined. The secular trends show weak surface cooling over the central Pacific between 140°W and 160°W near the Equator, consistent with the anomalous wind divergence and thermocline shoaling in the same region. In response to decadal and lower-frequency oscillatory wind forcing, the background state of the thermocline is modified in a way that when western-central Pacific is dominated by shoaling (deepening), the eastern Pacific is dominated by deepening (shoaling). The combined effect of the secular trends and lower-frequency oscillatory variability is that for some decade(s), the thermocline depth is anomalously shallower (deeper) in the western-central Pacific region, while the thermocline depth is anomalously deeper (shallower) in the east. We suggest that this "seesaw" pattern in the depth anomalies across the Equator determines the evolving patterns of ENSO by hinder/facilitating the communication between ocean surface and subsurface, and thus modifying the effect of wave-associated thermocline displacements on SST change over the western-central Pacific. Additionally, for WCP and some of the MIX ENSO events, a potential SSTA precursor from Baja California/northeastern Pacific might be instrumental to the subsequent development, possibly by inducing zonal wind anomalies in the western Pacific. / A Dissertation submitted to the Department of Earth, Ocean and Atmospheric Science in partial fulfillment of the Doctor of Philosophy. / Spring Semester, 2015. / April 6, 2015. / ENSO, FMEEMD, SST / Includes bibliographical references. / Zhaohua Wu, Professor Directing Dissertation; Ming Ye, University Representative; Allan Clarke, Committee Member; Guosheng Liu, Committee Member; Philip Sura, Committee Member.

The effects of mesoscale (50-1000km) sea surface temperature (SST) variability on tropical cyclones (TCs) are investigated with model simulations of an idealized TC as well as simulations of Hurricane Igor (2010) using the Weather Research and Forecasting (WRF) model. Mesoscale SST gradients significantly modify the surface wind speed and direction leading to areas of enhanced divergence/convergence and curl along the gradient. This paper explores the effects that these interactions between mesoscale SST gradients and the atmosphere have on TCs. In these idealized simulations it is shown that an SST gradient of similar scale to the idealized TC vortex produces asymmetry in the eyewall convection and leads to vertical misalignment of the vortex. Simulations of Igor are conducted with three different SST setups: a run with an unaltered SST field, a run with increased SST gradients, and a run with decreased SST gradients. Igor's intensity and structure is found to be sensitive to the three different SST setups but the specific mechanism could not be identified. It is found that the magnitude of moisture advection increases with increasing SST gradient magnitude on the warm side of a gradient. / 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. / Fall Semester, 2014. / November 5, 2014. / Air-Sea Interaction, Numerical Modeling, Sea Surface Temperature, Tropical Cyclones, Tropical Meteorology / Includes bibliographical references. / Mark Bourassa, Professor Co-Directing Thesis; Robert Hart, Professor Co-Directing Thesis; Mark Powell, Committee Member; Vasu Misra, Committee Member.

The Hengchun Peninsula (HCP) of southern Taiwan represents the newest emergent segment of the orogen built by the ongoing oblique collision between the Luzon arc and Eurasia continent. Newly recognized exposures indicate that a unit with the lithology of the Shihtzutou unit underlies the Lilongshan unit with a depositional contact. This discovery shows that Shihtzutou-type sands accumulated at least twice during the deposition of the Mutan Formation, and are in sedimentary contact with the Lilongshan unit. Fission-track analysis of detrital zircons reveals three age components from the samples analyzed from the HCP, which are 15, 34, and 66 Ma. These age components coincide with the thermal events of the opening of the South China Sea.Uplift rates calculated from the pattern of horizontal motions observed by a network of GPS stations, coupled with the equation of conservation, indicate the need for the Fengkang fault to accommodate a significant differential in uplift rates north and south of this fault. To a first degree, predicted uplift rates agree with data available on uplift across Taiwan. The source terranes for the Miocene sedimentary sequences of the HCP likely formed by the following scenario. Rifting of the South China Sea (SCS) began in the Late Cretaceous, which created rift basins off the southeast coast of China. A second rift episode of the SCS during the Eocene then intersected the early rift basins and carried some rifted blocks of the continental margin farther from Asia, while at the same time creating new mafic crust that was later accreted into the forearc of the approaching Luzon arc. Between 10 Ma and 5 Ma the Manila trench encountered and accreted the rifted microcontinental blocks and blocks of young mafic crust, and raised them to a subaerial environment to provide eroded detritus including rounded pebbles to the HCP basin. These sediments were deposited into the HCP basin in different fan systems with different source terranes and paleoflow directions. From 5 Ma to the present, the HCP basin itself was incorporated into the accretioanry wedge and brought to its current position by the fast-moving Philippine Sea plate. / A Dissertation submitted to the Department of Geological Sciences in partial fulfillment of the requriements for the degree of Doctor of Philosophy. / Degree Awarded: Fall Semester, 2003. / Date of Defense: October 23, 2003. / Hengchun Peninsula, Taiwan, Predicted Uplift rate, Zircon Fission-track Analysis, Tectonic Evolution / Includes bibliographical references. / Neil Lundberg, Professor Directing Dissertation; John W. Winchester, Outside Committee Member; LeRoy Odom, Committee Member; James F. Tull, Committee Member.

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.