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Title: The Influence of Atmospheric Cold Air Outbreaks on the Upper Ocean Thermal Variability of the Florida Straits.
Creator: Rudzin, Johna, Earth, Ocean & Atmospheric Science
Abstract/Description: The purpose of this study is to investigate the impacts of cold air outbreaks (CAOs) on the sea surface temperature (SST) in the Florida Straits (FS) during different configurations (mature or immature) of the Loop Current (LC). A satellite-derived SST data set is used to calculate the difference in SST anomalies between the FS and the Yucatan Channel (YC). The SST anomaly time series is analyzed during the winter season for times of mature and immature LC configurations determined from a...
Show moreThe purpose of this study is to investigate the impacts of cold air outbreaks (CAOs) on the sea surface temperature (SST) in the Florida Straits (FS) during different configurations (mature or immature) of the Loop Current (LC). A satellite-derived SST data set is used to calculate the difference in SST anomalies between the FS and the Yucatan Channel (YC). The SST anomaly time series is analyzed during the winter season for times of mature and immature LC configurations determined from a satellite altimetry-derived time series of LC position. This analysis shows a greater likelihood of anomalous cooling of SSTs in the FS compared to the SSTs in the YC during times of an extended, or mature, LC. This result leads to the hypothesis that surface water is subject to greater cooling during a mature LC (due to the greater residence time of the water under cold air masses) than an immature LC, and this cooler water is advected into the FS. This hypothesis is investigated by computing an approximate heat budget for the Yucatan-Loop-Florida Current (YLFC) under identical atmospheric forcing using twin ocean model simulations with mature and immature LC configurations.
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Date Issued: 2012
Identifier: FSU_migr_uhm-0056
Format: Thesis

Title: Multi-Decadal Variations of Durations of Extreme Temperatures in the Southeastern United States.
Creator: Worsnop, Rochelle, Earth, Ocean & Atmospheric Science
Abstract/Description: The number of extreme temperature occurrences and their durations in the southeast United States varies during three periods: the Warm Regime subset (WRs), the Cold Regime subset (CRs), and the Modern Record (MR). Multidecadal variations in the regional patterns of the counts and durations of summer-day and winter-day extremes reveal that during the MR, the extreme temperature counts and durations in Florida are more consistent with a WRs setup whereas these parameters for the inland states ...
Show moreThe number of extreme temperature occurrences and their durations in the southeast United States varies during three periods: the Warm Regime subset (WRs), the Cold Regime subset (CRs), and the Modern Record (MR). Multidecadal variations in the regional patterns of the counts and durations of summer-day and winter-day extremes reveal that during the MR, the extreme temperature counts and durations in Florida are more consistent with a WRs setup whereas these parameters for the inland states (Alabama, Georgia, North Carolina, and South Carolina) are more consistent with a CRs setup. We also found that during the CRs (WRs), the majority of stations show a statistically significant increase in the likelihood of exactly one winter-day (summer-day) extreme occurrence. During the MR, both inland and coastal stations show a statistically significant increase in the likelihood of exactly one winter-day occurrence. This increased likelihood is not seen during the MR for a summer-day extreme occurrence. Patterns in the behavior of summer-day and winter-day extremes during the CRs and WRs may provide insight about how extreme temperatures will behave in future periods, if the period is forecasted to have similar setups to that of the CRs or WRs. Insight about the duration and counts of extreme temperatures is useful to the agricultural community, power industries, and health officials.
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Date Issued: 2012
Identifier: FSU_migr_uhm-0050
Format: Thesis

Title: A Case Study of 2010 Hurricane Karl to Evaluate the Precipitation Forecasts of the Post Updated 2010 Global Ensemble Forecast System.
Creator: Day, Lindsey, Earth, Ocean & Atmospheric Science
Abstract/Description: This research project seeks to evaluate the rainfall forecast accuracy of the GEFS (Global Ensemble Forecast System) following the 2010 model update, analyzing the Atlantic September 2010 Hurricane Karl as a case study. Archived forecasted accumulated precipitation amounts from the GEFS are compared with archived CMORPH (CPC Morphing Technique) precipitation estimates. A sequence of 15 six hour forecasts from 1200 UTC 14 September 2010 to 1200 UTC 18 September 2010 are graphically displayed...
Show moreThis research project seeks to evaluate the rainfall forecast accuracy of the GEFS (Global Ensemble Forecast System) following the 2010 model update, analyzing the Atlantic September 2010 Hurricane Karl as a case study. Archived forecasted accumulated precipitation amounts from the GEFS are compared with archived CMORPH (CPC Morphing Technique) precipitation estimates. A sequence of 15 six hour forecasts from 1200 UTC 14 September 2010 to 1200 UTC 18 September 2010 are graphically displayed using GrADS (Grid Analysis and Display System). Four images were produced for each of the 15 six-hour time frames: A) CMORPH 6-hour accumulated precipitation, B) GEFS 6-hour accumulated precipitation, C) Difference in GEFS and CMORPH 6-hour accumulated precipitation (GEFS-CMORPH), and D) Overlay of outlined areas of medium (≥0.25 inches) and heavy (≥1.0 inches) precipitation for the GEFS and CMORPH. Several errors in the precipitation forecast of the GEFS model post-update were consistent with errors found in the GEFS model prior to its 2010 update from previous studies. For example, the GEFS forecasted the size of the hurricane to be too large for all evaluated times. Although the six hour GEFS track forecast was closely aligned with that of the verified track, major differences between the forecast and verification occurred as the storm approached its second landfall in Mexico. This study highlights that although the model may accurately depict the storm track, other model biases such as a lower resolution, difficulty depicting the atmosphere near land/sea boundaries and over complex terrain—may significantly impact the precipitation forecast.
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Date Issued: 2011
Identifier: FSU_migr_uhm-0011
Format: Thesis

Title: A Case Study of a Hybrid Cyclone: 6-9 September 2009.
Creator: Sliwinski, Timothy, Earth, Ocean & Atmospheric Science
Abstract/Description: Hybrid cyclones, such as subtropical storms and warm seclusions, are generally defined by the fact that they contain characteristics of the main types of cyclones: tropical and extratropical. This case study examines whether a cyclone can be considered hybrid without experiencing a transition from either of these two main types. The case in question occurred between 6 and 9 September 2009 before becoming frontal. The cyclone formed independently of other cyclones and was shallow warm-core at...
Show moreHybrid cyclones, such as subtropical storms and warm seclusions, are generally defined by the fact that they contain characteristics of the main types of cyclones: tropical and extratropical. This case study examines whether a cyclone can be considered hybrid without experiencing a transition from either of these two main types. The case in question occurred between 6 and 9 September 2009 before becoming frontal. The cyclone formed independently of other cyclones and was shallow warm-core at its start. It would go on to exhibit properties of tropical cyclones such as a stacked surface warm-core and even convection occurring at the center. It would also go on to exhibit properties of extratropical cyclones by strengthening whenever an upper-level shortwave came near, increasing baroclinicity. This study looks at the large-scale patterns of development and utilizes the diagnostic properties of the terms of the quasi-geostrophic omega equation to understand the forcings in the area of the cyclone as depicted in the North American Regional Reanalysis. In addition, cyclone phase diagrams were generated for other analyses to determine whether the characteristics depict hybrid, extratropical, tropical, or subtropical development based on the parameters of thermal wind and thermal symmetry. It was found that the system was a hybrid system in that a warm-core surface cyclone did exist from the surface to 500 hPa; however upper-level short waves about an upper-level trough were responsible for providing forcing for the genesis and strengthening of this storm.
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Date Issued: 2011
Identifier: FSU_migr_uhm-0038
Format: Thesis

Title: Determinig the Effects of Stokes Drift on the Movement of Oil in the Gulf of Mexico.
Creator: Heath, Nicolas, Earth, Ocean & Atmospheric Science
Abstract/Description: The impact of Stokes drift, a wave-driven mechanism of mass transport, is investigated for surface oil movement in the Gulf of Mexico. Stokes drift was neglected in trajectory forecasts in the Gulf during the Deepwater Horizon oil spill. The key considerations used in Gulf of Mexico trajectory forecasts were surface currents and wind drift. This study presents a physical argument for the importance of Stokes drift and questions the significance of wind drift over an oil slick. Furthermore,...
Show moreThe impact of Stokes drift, a wave-driven mechanism of mass transport, is investigated for surface oil movement in the Gulf of Mexico. Stokes drift was neglected in trajectory forecasts in the Gulf during the Deepwater Horizon oil spill. The key considerations used in Gulf of Mexico trajectory forecasts were surface currents and wind drift. This study presents a physical argument for the importance of Stokes drift and questions the significance of wind drift over an oil slick. Furthermore, the magnitude and direction of the wind drift (2–5% of the wind speed and 20° to the right in the Northern Hemisphere) is very similar to that of the Stokes drift. For this reason, the differences between Stokes drift and the wind drift are examined using a vector comparison. The directional components of Stokes drift and the wind drift are found to be very similar although the magnitudes of the wind drift are found to be larger. When swell not associated with the local wind is present, however, the two drifts have significantly different directional components. Horizontal surface trajectories are computed for different atmospheric and oceanic conditions. Trajectory results are compared to satellite-derived oil locations using a center of mass comparison method. Analysis of trajectory forecasts and observed oil locations suggests that Stokes drift might play an important role in the movement of oil at the surface and that the magnitude of the wind drift may not be as large as most models presume. Key
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Date Issued: 2011
Identifier: FSU_migr_uhm-0017
Format: Thesis

Title: Characteristics of WTLN-Derived Lightning.
Creator: Saunders, Matthew, Earth, Ocean & Atmospheric Science
Abstract/Description: Many studies have used cloud-to-ground (CG), intracloud (IC), and total (CG + IC) lightning to investigate relationships between lightning and severe weather. Although the National Lightning Detection Network (NLDN) is the most common system used to detect lightning, it is limited to reporting only CG lightning over the continental United States. The WeatherBug Total Lightning Network (WTLN) is a global data set recently established by Earth Networks, Inc. that reports both CG and IC...
Show moreMany studies have used cloud-to-ground (CG), intracloud (IC), and total (CG + IC) lightning to investigate relationships between lightning and severe weather. Although the National Lightning Detection Network (NLDN) is the most common system used to detect lightning, it is limited to reporting only CG lightning over the continental United States. The WeatherBug Total Lightning Network (WTLN) is a global data set recently established by Earth Networks, Inc. that reports both CG and IC lightning. WTLN has the potential to offer superior lightning data, although little research has compared WTLN information to other data sets like the NLDN. Using WTLN and NLDN data, distributions of stroke counts by polarity and peak current were plotted during a16-month study period near Cape Canaveral, FL. The WTLN data set showed an over detection of weak peak current strokes and under detection of strong peak current strokes. The WTLN data also exhibited higher overall stroke counts compared to NLDN. A case study of the Tuscaloosa-Birmingham tornado showed an opposite relation between WTLN and NLDN stroke counts. Compared to NLDN, the WTLN continually undercounted strokes during the lifecycle of the storm. While the number of counts was dissimilar, the two data sets correlated strongly (0.79) during the storm period. When the lightning was divided by polarity, WTLN showed a much greater detection of positive CG lightning than NLDN.
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Date Issued: 2012
Identifier: FSU_migr_uhm-0055
Format: Thesis

Title: Analysis of GFDL Intensity Forecasting Performance for Gulf/Caribbean Major Hurricanes from 1998-2008.
Creator: Hazelton, Andrew, Earth, Ocean & Atmospheric Science
Abstract/Description: While both computer model and official track forecasts of Atlantic Basin hurricanes have improved significantly over the past several decades, forecasts of intensity continue to prove difficult. Even specialized hurricane models struggle with predicting intensity. This study analyzes the intensity errors of the Geophysical Fluid Dynamics Laboratory (GFDL) Hurricane Model for 19 major hurricanes over the Gulf of Mexico and Caribbean Sea from 1998 to 2008. Using the measure of skill relative to...
Show moreWhile both computer model and official track forecasts of Atlantic Basin hurricanes have improved significantly over the past several decades, forecasts of intensity continue to prove difficult. Even specialized hurricane models struggle with predicting intensity. This study analyzes the intensity errors of the Geophysical Fluid Dynamics Laboratory (GFDL) Hurricane Model for 19 major hurricanes over the Gulf of Mexico and Caribbean Sea from 1998 to 2008. Using the measure of skill relative to the Statistical Hurricane Intensity Forecast (SHIFOR), the GFDL forecasts generally improved throughout most of the 11-year period, although there were some exceptions to this increase in skill. Comparing the GFDL to the Statistical Hurricane Intensity Prediction Scheme (SHIPS), it is found that the GFDL was slightly outperformed by SHIPS on most of the forecast categories and times. It seems that there is a correlation between higher intensity storms and higher errors (R = 0.53), and there is also a clear relationship between large negative errors and rapid intensification (R = 0.62). This relationship is explored for some of the ―higher-error‖ cases by comparing the GFDL forecast intensity progression with the actual intensity change. Hurricanes Dean (2007) and Felix (2007) are also analyzed in more detail, since both of these storms were exceptions to the general trend in increased skill from 2000-2008. It is hoped that this and further analysis will illuminate reasons for the model's difficulty with the intensity forecasts, and provide a basis for improving model forecasts and official forecasts of tropical cyclone intensity.
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Date Issued: 2011
Identifier: FSU_migr_uhm-0014
Format: Thesis

Title: Hurricane Sandy and New Jersey: The Nature of a Natural Disaster.
Creator: Blaskiewicz, Claire S., Department of Earth, Ocean and Atmospheric Sciences
Abstract/Description: While natural disasters can often be catalysts for change, understanding where to begin changing can be discovered by looking at the science and history of the affected area. Hurricane Sandy's unprecedented landfall in October 2012 began this progression for the state of New Jersey. This study examines the processes affecting the ocean and beaches of New Jersey, looks at the effects of Hurricane Sandy on the state and discusses the changing standards that have been and continue to be enacted...
Show moreWhile natural disasters can often be catalysts for change, understanding where to begin changing can be discovered by looking at the science and history of the affected area. Hurricane Sandy's unprecedented landfall in October 2012 began this progression for the state of New Jersey. This study examines the processes affecting the ocean and beaches of New Jersey, looks at the effects of Hurricane Sandy on the state and discusses the changing standards that have been and continue to be enacted since storm recovery began. Specifically highlighted are the engineering practices of flood mitigation, the effects of the storm on the state's economy and the new policies and standards that have come about in the aftermath.
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Date Issued: 2014
Identifier: FSU_migr_uhm-0564
Format: Thesis

Atmospheric sciences (8)	+ -
Meteorology (8)	+ -
Oceanography (7)	+ -
Atmospheric physics (3)	+ -

Earth, Ocean & Atmospheric Science (7)	+ -
Blaskiewicz, Claire S. (1)	+ -
Day, Lindsey (1)	+ -
Department of Earth, Ocean and Atmospheric Sciences (1)	+ -
Hazelton, Andrew (1)	+ -

Heath, Nicolas (1)	+ -
Rudzin, Johna (1)	+ -
Saunders, Matthew (1)	+ -
Sliwinski, Timothy (1)	+ -
Worsnop, Rochelle (1)	+ -

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