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- Title
- A review of multimodel superensemble forecasting for weather, seasonal climate, and hurricanes.
- Creator
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Krishnamurti, T. N., Kumar, V., Simon, A., Bhardwaj, A., Ghosh, T., Ross, R.
- Abstract/Description
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This review provides a summary of work in the area of ensemble forecasts for weather, climate, oceans, and hurricanes. This includes a combination of multiple forecast model results that does not dwell on the ensemble mean but uses a unique collective bias reduction procedure. A theoretical framework for this procedure is provided, utilizing a suite of models that is constructed from the well-known Lorenz low-order nonlinear system. A tutorial that includes a walk-through table and...
Show moreThis review provides a summary of work in the area of ensemble forecasts for weather, climate, oceans, and hurricanes. This includes a combination of multiple forecast model results that does not dwell on the ensemble mean but uses a unique collective bias reduction procedure. A theoretical framework for this procedure is provided, utilizing a suite of models that is constructed from the well-known Lorenz low-order nonlinear system. A tutorial that includes a walk-through table and illustrates the inner workings of the multimodel superensemble's principle is provided. Systematic errors in a single deterministic model arise from a host of features that range from the model's initial state (data assimilation), resolution, representation of physics, dynamics, and ocean processes, local aspects of orography, water bodies, and details of the land surface. Models, in their diversity of representation of such features, end up leaving unique signatures of systematic errors. The multimodel superensemble utilizes as many as 10 million weights to take into account the bias errors arising from these diverse features of multimodels. The design of a single deterministic forecast models that utilizes multiple features from the use of the large volume of weights is provided here. This has led to a better understanding of the error growths and the collective bias reductions for several of the physical parameterizations within diverse models, such as cumulus convection, planetary boundary layer physics, and radiative transfer. A number of examples for weather, seasonal climate, hurricanes and sub surface oceanic forecast skills of member models, the ensemble mean, and the superensemble are provided.
Show less - Date Issued
- 2016-06
- Identifier
- FSU_libsubv1_wos_000385716900003, 10.1002/2015RG000513
- Format
- Citation
- Title
- An Examination of the Differences in Tropical Cyclone Pressure-Wind Relationships Among Observations, Model Analyses, and Model Forecasts.
- Creator
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Visin, Lauren, Department of Earth, Ocean and Atmospheric Sciences
- Abstract/Description
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Despite significant advances in tropical cyclone (TC) track forecasting over the past few decades, intensity forecasts remain problematic, even for high-resolution computer models uniquely developed and tailored to TC prediction. This study examines the ability of two of these models, the Geophysical Fluid Dynamics Laboratory (GFDL) model and the Hurricane Weather Research and Forecasting (HWRF) model, to analyze and predict one measure of TC structure in the Atlantic Basin. Instead of more...
Show moreDespite significant advances in tropical cyclone (TC) track forecasting over the past few decades, intensity forecasts remain problematic, even for high-resolution computer models uniquely developed and tailored to TC prediction. This study examines the ability of two of these models, the Geophysical Fluid Dynamics Laboratory (GFDL) model and the Hurricane Weather Research and Forecasting (HWRF) model, to analyze and predict one measure of TC structure in the Atlantic Basin. Instead of more conventional evaluations based solely on a TC's maximum wind speed or minimum sea level pressure (MSLP), the relationship between these two variables is used: a TC's pressure-wind relationship (PWR), which gives a more detailed look at how well each model analyzes and forecasts TC structure. The analysis begins in 2007, the year the GFDL was initially "frozen" (development and improvements were ceased) and also the first year that the HWRF was used for operational forecasting. Comparison of both GFDL and HWRF analyses and forecasts to the National Hurricane Center's (NHC) "best track" (database of 6-hourly observations of vital statistics such as maximum wind speed and MSLP for all TCs) revealed that, while both models produced errors in their analyses and forecasts, the GFDL outperformed the HWRF in both analysis and forecasting of TC PWR's for Atlantic Basin hurricanes from 2007-2013.. There was a subsection of particularly strong TCs (maximum winds above 120kt, MSLP lower than 950mb) whose structure was forecast especially poorly. The forecast PWR's produced by the HWRF fell largely outside the "best track" for this set of intense TCs, suggesting that the structures produced by the HWRF are inconsistent with our best estimates of observations in the Atlantic Basin and given current climate conditions. The PWR distribution evolved considerably for the HWRF over time, presumably as model improvements were made (including a decrease in model gridspacing). This has led to the model analysis PWR becoming more consistent with the model forecast PWR envelope. Nonetheless, both often fall outside the best-track estimates of PWR and potential explanations for this disparity are presented.
Show less - Date Issued
- 2014
- Identifier
- FSU_migr_uhm-0386
- Format
- Thesis
- Title
- The Accuracy of the National Hurricane Center's United States Tropical Cyclone Landfall Forecasts in the Atlantic Basin (2004–2012).
- Creator
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Keclik, Alexandra, Department of Earth, Ocean and Atmospheric Sciences
- Abstract/Description
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This study examined the position, timing, and intensity of each National Hurricane Center's (NHC) Official Forecasts (OFCL) for Atlantic tropical storms and hurricanes that made landfall in the United States from 2004 to 2012. During that time period, one hundred and fifty tropical cyclones developed in the Atlantic basin. Thirty-two of the cyclones made landfall in the United States as tropical storms or hurricanes. Accurate predictions of the location, timing, and intensity of tropical...
Show moreThis study examined the position, timing, and intensity of each National Hurricane Center's (NHC) Official Forecasts (OFCL) for Atlantic tropical storms and hurricanes that made landfall in the United States from 2004 to 2012. During that time period, one hundred and fifty tropical cyclones developed in the Atlantic basin. Thirty-two of the cyclones made landfall in the United States as tropical storms or hurricanes. Accurate predictions of the location, timing, and intensity of tropical cyclone landfalls are important, so that people in a storm's track can prepare adequately for heavy to catastrophic wind, rain, and storm surge. The errors of each of the OFCL for Atlantic tropical storms and hurricanes that made landfall in the United States during 2004–2012 are acquired from the Best Track data set. The ELTOPO1 landmask is used to find the forecasted landfall point using sequential locations from the OFCL offshore and onshore points of each forecast. The great circle distance between the forecasted and actual landfall constitutes the location error. The official landfall time is subtracted from the forecasted landfall time to find the timing error, and the official landfall wind speed is subtracted from the closest to onshore wind speed to find intensity error. There is a trend of decreasing error in location, timing, and intensity forecasting with decreasing lead time. An improvement in tropical cyclone landfall forecasting is found from comparing the 2004–2012 Atlantic landfall forecast errors to those in a study of 1976-2000 forecasts.
Show less - Date Issued
- 2014
- Identifier
- FSU_migr_uhm-0324
- Format
- Thesis
- Title
- Analysis of Convective Transport of Biomass Burning Emissions in Southeast Asia.
- Creator
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Ahern, Kyle, Department of Earth, Ocean and Atmospheric Sciences
- Abstract/Description
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Biomass burning and anthropogenic emissions affect the composition of the atmosphere, thereby impacting global climate and health. Deep convective processes can loft emissions from the boundary layer into the upper troposphere or lower stratosphere (UTLS). Strong upper-level winds can potentially transport the emissions over long distances. This study focused on the deep convective transport of biomass burning emissions near the Strait of Malacca during summer. The Weather Research and...
Show moreBiomass burning and anthropogenic emissions affect the composition of the atmosphere, thereby impacting global climate and health. Deep convective processes can loft emissions from the boundary layer into the upper troposphere or lower stratosphere (UTLS). Strong upper-level winds can potentially transport the emissions over long distances. This study focused on the deep convective transport of biomass burning emissions near the Strait of Malacca during summer. The Weather Research and Forecasting (WRF) and Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT_4) models were used to investigate deep convection and the transport of emissions from fires in the region. Fire data from the Moderate-resolution Imaging Spectroradiometer (MODIS) sensors onboard the Aqua and Terra satellites provided locations of fire emissions. These fire datasets were obtained from the University of Maryland's Fire Information for Resource Management System (FIRMS). To investigate the deep convective processes thoroughly, this study used high resolution modeling (4 km grid spacing) to resolve the convection explicitly. Explicit resolution allows the thunderstorms to be simulated more realistically than would parameterization, thus making it ideal for this research. Results showed that deep convection occurring in the Strait of Malacca is driven primarily by diurnal heating patterns and the region's topography. Convection in the region is frequent and scattered, but follows a cyclic diurnal pattern: convection over land during daytime and over the Strait during nighttime. When emissions from fires encounter areas of deep convection, they are quickly lofted to the UTLS where winds then transport them elsewhere.
Show less - Date Issued
- 2013
- Identifier
- FSU_migr_uhm-0216
- Format
- Thesis
- Title
- The Increasing Intensity and Frequency of ENSO and its Impacts to the Southeast U.S.
- Creator
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McNaught, Carlysle, Department of Earth, Ocean and Atmospheric Sciences
- Abstract/Description
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The El Niño Southern Oscillation (ENSO) is an important natural climate variation that affects large portions of the world. The changing magnitude and frequency of ENSO reveals that it is getting stronger as measured by the maximum anomaly in sea surface temperature (SST). Principal component analysis of the ENSO is conducted to estimate the spectrum of the SST of the time series. The intensity of the ENSO events during the period 1970—2010 is statistically significantly higher when compared...
Show moreThe El Niño Southern Oscillation (ENSO) is an important natural climate variation that affects large portions of the world. The changing magnitude and frequency of ENSO reveals that it is getting stronger as measured by the maximum anomaly in sea surface temperature (SST). Principal component analysis of the ENSO is conducted to estimate the spectrum of the SST of the time series. The intensity of the ENSO events during the period 1970—2010 is statistically significantly higher when compared to the period 1930—1970, with a broad spectral peak centered around 4 years. When we compare the SST spectrum for the period 1930—1970 with the spectrum for 1970—2010, we find the latter period to be much stronger in power. The resultant impact of more powerful and frequent ENSO events on the Southeast United States is examined through a spatial and temporal statistical analysis of precipitation and temperatures between the two time periods. Our analysis reveals statistically significant changes in precipitation during El Niño where the rainfall is much more widespread across the Southeast during the 1970—2010 period than the 1930—1970 period. The La Niña rainfall deficit is mainly confined to Florida in the latter period than the former. Finally, the temperature distribution, through an analysis of the first four statistical moments, showed conventional responses to the changes in ENSO precipitation such as an anomalous decrease in maximum temperatures during El Niño and an overall anomalous increase in temperatures during La Niña.
Show less - Date Issued
- 2014
- Identifier
- FSU_migr_uhm-0356
- Format
- Thesis
- Title
- Examining Shifts in Warm-Season Near-Surface Moisture Trends in Florida.
- Creator
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Swearingen, Aaron D., Department of Earth, Ocean and Atmospheric Sciences
- Abstract/Description
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Warm-season (1 June–31 August) near-surface moisture trends have been examined across Florida. Data was used from 86 National Weather Service cooperative stations, 24 NWS first-order stations, and the European Centre for Medium-Range Weather Forecasts' ERA-Interim satellite reanalysis. Seventy-five out of eighty-six NWS cooperative stations depicted high counts of maximum low temperature records being set or broken since 1990. Twenty-four NWS hourly stations were used in conjunction with the...
Show moreWarm-season (1 June–31 August) near-surface moisture trends have been examined across Florida. Data was used from 86 National Weather Service cooperative stations, 24 NWS first-order stations, and the European Centre for Medium-Range Weather Forecasts' ERA-Interim satellite reanalysis. Seventy-five out of eighty-six NWS cooperative stations depicted high counts of maximum low temperature records being set or broken since 1990. Twenty-four NWS hourly stations were used in conjunction with the Pettitt test to calculate a change point of 1990 over a 40-year period (1973–2012). Using the Pettitt results, a significant amount of NWS first-order stations depicted a rise in both early morning temperatures and dew points (Td) since 1990. A rise in total column water vapor (TCWV) was detected through the ERA-Interim reanalysis, indicating a possible increase in mid-level moisture in addition to that near the surface. A reversal in 850 hPa wind patterns and a potential shift in the Azores High were present in the reanalysis as well. An increase in atmospheric moisture levels is present and may be driven by synoptic-scale changes in wind patterns due to a shift in the Azores High.
Show less - Date Issued
- 2015
- Identifier
- FSU_migr_uhm-0528
- Format
- Thesis
- Title
- A High Resolution Atmospheric Chemistry Simulation of Hurricane Sandy (2012).
- Creator
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Freeman, Sean, Department of Earth, Ocean and Atmospheric Sciences
- Abstract/Description
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Hurricane Sandy (2012) had one of the greatest economic impacts of any hurricane in United States history. However, its broader scientific impacts, especially its impacts on the chemistry of the upper troposphere and lower stratosphere, have not been documented. This study uses the Weather Research and Forecasting with Chemistry model (WRF-Chem), run at a convective-permitting resolution, to examine the transport of pollutants inside Hurricane Sandy as it made landfall along the Eastern...
Show moreHurricane Sandy (2012) had one of the greatest economic impacts of any hurricane in United States history. However, its broader scientific impacts, especially its impacts on the chemistry of the upper troposphere and lower stratosphere, have not been documented. This study uses the Weather Research and Forecasting with Chemistry model (WRF-Chem), run at a convective-permitting resolution, to examine the transport of pollutants inside Hurricane Sandy as it made landfall along the Eastern Seaboard. Although several pollutants were examined, the concentrations of CO throughout the atmosphere and the transport of CO from sources along the coast in Hurricane Sandy's convective region were primary focus. A forward-trajectory analysis also was performed using the high-resolution WRF-Chem data as input to the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT). The results of this high-resolution chemical and meteorological simulation will be presented with a focus on transport to the upper troposphere and lower stratosphere. To our knowledge, such high-resolution chemical and meteorological simulations of tropical cyclones have not been reported in the previous literature.
Show less - Date Issued
- 2015
- Identifier
- FSU_migr_uhm-0477
- Format
- Thesis
- Title
- Stratospheric Polar Vortex Warming and Cold Air Outbreaks: A Case Study.
- Creator
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Perrini, Nikki, Department of Earth, Ocean and Atmospheric Sciences
- Abstract/Description
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The predictability of the stratospheric circulations and the connection between the stratospheric branch and cold air branch allow us to predict large continental-scale cold air outbreaks with ample lead-time. Based on this, we have made experimental sub-seasonal forecasts for cold air outbreaks across the mid-latitude regions of North America, Europe, and Eastern Asia. The forecasts made in this winter have provided the public with a lead-time of 20-45 days for individual cold air outbreak...
Show moreThe predictability of the stratospheric circulations and the connection between the stratospheric branch and cold air branch allow us to predict large continental-scale cold air outbreaks with ample lead-time. Based on this, we have made experimental sub-seasonal forecasts for cold air outbreaks across the mid-latitude regions of North America, Europe, and Eastern Asia. The forecasts made in this winter have provided the public with a lead-time of 20-45 days for individual cold air outbreak events. This thesis also made a case study of a strong stratospheric circulation event called "STRAT_E", which had the longest duration and was the most intense cold air outbreak episode. The case study helps to further explain the processes behind cold air outbreaks.
Show less - Date Issued
- 2015
- Identifier
- FSU_migr_uhm-0535
- Format
- Thesis
- Title
- An Analysis of the Extratropical Flow Response to Recurving Atlantic Tropical Cyclones.
- Creator
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Brannan, Allison, Department of Earth, Ocean and Atmospheric Sciences
- Abstract/Description
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There is a significant frequency of Atlantic tropical cyclones that complete extratropical transition and recurve in the mid-latitudes. Using a climatological approach, this study will analyze the extratropical flow response to recurving Atlantic tropical cyclones and compare the results to those from the Western North Pacific, as examined by Archambault et al. (2013). This investigation includes 54 recurving Atlantic tropical cyclones occurring between 2007 and 2013. The extratropical flow...
Show moreThere is a significant frequency of Atlantic tropical cyclones that complete extratropical transition and recurve in the mid-latitudes. Using a climatological approach, this study will analyze the extratropical flow response to recurving Atlantic tropical cyclones and compare the results to those from the Western North Pacific, as examined by Archambault et al. (2013). This investigation includes 54 recurving Atlantic tropical cyclones occurring between 2007 and 2013. The extratropical flow response will be quantified using potential vorticity. Characteristics of tropical cyclones, the extratropical jet stream, and the dynamical "phasing" of their interaction will be examined to determine the features that lead to significantly amplified extratropical flow. Results show the extratropical flow to be insensitive to the wind speed, latitude, and month of recurvature. However, there is an association between low mean sea level pressure and a larger amplification of flow. Finally, tropical cyclones recurving on the east side of the nearest trough are shown to have "favorable phasing," which yields amplification of the extratropical flow.
Show less - Date Issued
- 2015
- Identifier
- FSU_migr_uhm-0538
- Format
- Thesis
- Title
- Hurricane Sandy and New Jersey: The Nature of a Natural Disaster.
- Creator
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Blaskiewicz, Claire S., Department of Earth, Ocean and Atmospheric Sciences
- Abstract/Description
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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.
Show less - Date Issued
- 2014
- Identifier
- FSU_migr_uhm-0564
- Format
- Thesis
- Title
- Investigating Relationships Between Rising Temperatures and Heavy Rainfall Events in the Southeastern U.S. Using Analog Methods.
- Creator
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Zuromski, Lauren, Department of Earth, Ocean and Atmospheric Sciences
- Abstract/Description
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This study examines how extreme precipitation influences temperatures, and how temperature extremes influence precipitation in the Southeastern U.S., seasonally, using observational data. For the precipitation influencing temperature approach, three precipitation regimes are created (wet, dry, and neutral) to observe possible shifts in the distributions of seasonal average daily maximum and minimum temperatures based on precipitation extremes. Similarly, for the temperature influencing...
Show moreThis study examines how extreme precipitation influences temperatures, and how temperature extremes influence precipitation in the Southeastern U.S., seasonally, using observational data. For the precipitation influencing temperature approach, three precipitation regimes are created (wet, dry, and neutral) to observe possible shifts in the distributions of seasonal average daily maximum and minimum temperatures based on precipitation extremes. Similarly, for the temperature influencing precipitation, three temperature regimes are created (warm, cool, and neutral), to observe how the frequency of rainfall events of 1.00" or more shifts in each temperature regime. For the precipitation influencing temperature approach, most notably, it is found that in summer, spring, and fall, in a wet precipitation regime, the maximum temperatures are typically warmer (cooler) than the average maximum temperatures in a neutral regime; the opposite pattern is observed for winter. It is also found that these temperature distributions do not shift in a uniform way across the Southeast, though several regional continuities exist. For the temperature influencing precipitation approach, it is found that spring, summer, and winter show the largest differences in the frequency of rainfall events of 1.00" or more between the cool and warm temperature regimes. This study also examines five case study stations in the Southeast to observe regional nuances in temperature and precipitation patterns.
Show less - Date Issued
- 2015
- Identifier
- FSU_migr_uhm-0511
- Format
- Thesis
- Title
- IC to CG Lightning Relationships over the Tallahassee CWA.
- Creator
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Jackson, Karly M., Department of Earth, Ocean and Atmospheric Sciences
- Abstract/Description
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The formation of and the relationship between intra-cloud (IC) and cloud-to-ground (CG) lightning flashes have not been thoroughly studied. Understanding how these flash types interact in different types of thunderstorms can lead to a better understanding of lightning characteristics and how these characteristics can be applied to operational forecasting practices. Results of this study show that the IC:CG ratio varies greatly each day throughout the summer season over the County Warning Area...
Show moreThe formation of and the relationship between intra-cloud (IC) and cloud-to-ground (CG) lightning flashes have not been thoroughly studied. Understanding how these flash types interact in different types of thunderstorms can lead to a better understanding of lightning characteristics and how these characteristics can be applied to operational forecasting practices. Results of this study show that the IC:CG ratio varies greatly each day throughout the summer season over the County Warning Area (CWA) of the Tallahassee National Weather Service Forecast Office. The summer season is dominated by daily thunderstorms that form due to sea breeze fronts and their resulting outflow boundaries. Eleven case study storms reveal how IC and CG flash counts and rates in non-severe thunderstorms differ from those of severe storms such as those examined by Williams et al. (1999). Results of the present study reveal that the timing of CG lightning and the frequency of its strikes differ from those of severe storms. This is most likely due to severe storms producing stronger updrafts for longer periods of time than those of non-severe storms. The IC:CG ratios varied greatly among these case studies indicating that further studies must be done to determine a statistically significant understanding of how flash rates change and how the relationship between IC and CG flashes relate to the ratios they produce.
Show less - Date Issued
- 2015
- Identifier
- FSU_migr_uhm-0552
- Format
- Thesis
- Title
- Remotely Sensed Validation of Numerical Weather Prediction Estimates of Wind Speed Near Tropical Cyclones.
- Creator
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Dacey, Connor, Department of Earth, Ocean and Atmospheric Sciences
- Abstract/Description
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This study examined the tendencies of the European Center for Medium-Range Weather Forecasting Ensemble Prediction System (ECMWF-EPS) control forecast of wind speeds near two rapidly intensifying tropical cyclones (TCs) in the Indian Ocean. The ECMWF-EPS control forecasts were compared with the Advanced Scatterometer (ASCAT) wind speed measurements, which were considered comparison and "truth" data for this study. In total, 6 days of model forecast and ASCAT data were collected and analyzed...
Show moreThis study examined the tendencies of the European Center for Medium-Range Weather Forecasting Ensemble Prediction System (ECMWF-EPS) control forecast of wind speeds near two rapidly intensifying tropical cyclones (TCs) in the Indian Ocean. The ECMWF-EPS control forecasts were compared with the Advanced Scatterometer (ASCAT) wind speed measurements, which were considered comparison and "truth" data for this study. In total, 6 days of model forecast and ASCAT data were collected and analyzed for severe tropical cyclones Phet and Giri. Differences in the magnitudes of the wind speeds near the TCs were calculated. From these, areas can be seen in which the ECMWF-EPS control over-forecasted and under-forecasted the wind speeds. These results also help explain how the model tendencies changed throughout the lifespan of the TCs. Overall, wind speed errors were greatly associated with errors in storm location, storm shape, and storm size. No exact conclusion about the tendencies of the ECMWF-EPS control forecasts could be made due to a lack of patterns or clear biases associated with the wind speed difference results. A more in-depth study must be completed to further comment on specific tendencies of the model. Nevertheless, this study could begin the investigation into how to improve wind speed forecasts for TCs in the Indian Ocean in an effort to better save life and property in the future.
Show less - Date Issued
- 2015
- Identifier
- FSU_migr_uhm-0548
- Format
- Thesis
- Title
- Bias characterization of CrIS shortwave temperature sounding channels using fast NLTE model and GFS forecast field.
- Creator
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Yin, Mengtao
- Abstract/Description
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The strong nonlocal thermal equilibrium (NLTE) emission in the upper atmosphere impedes the usage of Cross-track Infrared Sounder (CrIS) temperature channels near 4.3 mu m in the operational data assimilation. This study explores the bias characteristics of those temperature channels near 4.3 mu m with and without a fast NLTE model implemented in the Community Radiative Transfer Model (CRTM). It is shown that the biases of those temperature channels can reach up to 12K and are dramatically...
Show moreThe strong nonlocal thermal equilibrium (NLTE) emission in the upper atmosphere impedes the usage of Cross-track Infrared Sounder (CrIS) temperature channels near 4.3 mu m in the operational data assimilation. This study explores the bias characteristics of those temperature channels near 4.3 mu m with and without a fast NLTE model implemented in the Community Radiative Transfer Model (CRTM). It is shown that the biases of those temperature channels can reach up to 12K and are dramatically reduced to below 4K during daytime by the fast NLTE model with small differences from the nighttime biases. However, the biases after applying the NLTE correction remain large for CrIS upper atmospheric temperature channels during both daytime and nighttime. A further investigation suggests that the remaining biases in those temperature channels mainly originate from the cold biases in the stratospheric temperature profiles of National Center for Environmental Prediction Global Forecast System (GFS) forecasts as input to CRTM. The cold biases reach the maximum of about 8K near the tropics at about 1hPa, decreasing toward higher latitudes and lower altitudes.
Show less - Date Issued
- 2016-02-16
- Identifier
- FSU_libsubv1_wos_000371481700014, 10.1002/2015JD023876
- Format
- Citation
- Title
- The Mean Upper-Layer Flow in the Central Gulf of Mexico by a New Method.
- Creator
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Sturges, Wilton
- Abstract/Description
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Previous studies have found a puzzling disagreement between two large datasets and the results of numerical models in the central Gulf of Mexico. The observations suggest an upper-layer mean flow to the west of order 10 cm s(-1), while the numerical models find no such mean flow. A new technique is used here, using 23 yr of satellite-derived sea surface height data, to estimate the mean flow. This third, independent set of data yields the same westward flow found in previous studies. These...
Show morePrevious studies have found a puzzling disagreement between two large datasets and the results of numerical models in the central Gulf of Mexico. The observations suggest an upper-layer mean flow to the west of order 10 cm s(-1), while the numerical models find no such mean flow. A new technique is used here, using 23 yr of satellite-derived sea surface height data, to estimate the mean flow. This third, independent set of data yields the same westward flow found in previous studies. These findings require that there be sinking in the western Gulf. The details of the return flow remain an intriguing problem.
Show less - Date Issued
- 2016-10
- Identifier
- FSU_libsubv1_wos_000384025700002, 10.1175/JPO-D-16-0062.1
- Format
- Citation
- Title
- Isotopic Analysis of Sediment from the DeSoto Canyon and Surrounding Channels in the Gulf of Mexico.
- Creator
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Pullon, Alton Garrett
- Abstract/Description
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This study examines changes with depth in the sediments of the DeSoto Canyon. Piston cores were collected at sites both within and outside the channels of the canyon and samples were collected at selected depths along the cores. Samples were analyzed for δ13C, δ15N, %C and %N. Depletion of δ13C and δ15N levels indicated greater contribution of terrestrial organic matter to the sediment, while an enrichment of these indicators suggested more marine inputs. It was determined that sediment...
Show moreThis study examines changes with depth in the sediments of the DeSoto Canyon. Piston cores were collected at sites both within and outside the channels of the canyon and samples were collected at selected depths along the cores. Samples were analyzed for δ13C, δ15N, %C and %N. Depletion of δ13C and δ15N levels indicated greater contribution of terrestrial organic matter to the sediment, while an enrichment of these indicators suggested more marine inputs. It was determined that sediment within the canyons tended to have only a shallow layer of marine derived sediment in the upper horizons of the sediment layers (1.5 cm - ~54.75 cm), while sediments that were sampled outside the canyon tended to have deeper marine composed sediment in the upper horizons of the sediment layers (1.5cm - ~67.5 cm). All sediment horizons transition to greater terrestrial composition at depth. This indicates that there may be removal of the upper layers of the marine derived sediment through erosion processes within the channels.
Show less - Date Issued
- 2018-04-20
- Identifier
- FSU_libsubv1_scholarship_submission_1524495854_80cd83f3
- Format
- Thesis
- Title
- Understanding The Variations Of The Length And The Seasonal Rainfall Anomalies Of The Indian Summer Monsoon.
- Creator
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Misra, Vasubandhu, Bhardwaj, Amit, Noska, Ryne
- Abstract/Description
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The canonical relationship between the length and the total seasonal rainfall anomalies of the Indian summer monsoon (ISM) is the association of the longer (shorter) season with wetter (drier) seasonal rainfall anomalies. This study shows that such canonical behavior is clearly associated with relatively strong ENSO SST anomalies in the eastern equatorial Pacific Ocean that appear in the boreal summer and fall seasons. The noncanonical relationship is caused by a longer (shorter) season...
Show moreThe canonical relationship between the length and the total seasonal rainfall anomalies of the Indian summer monsoon (ISM) is the association of the longer (shorter) season with wetter (drier) seasonal rainfall anomalies. This study shows that such canonical behavior is clearly associated with relatively strong ENSO SST anomalies in the eastern equatorial Pacific Ocean that appear in the boreal summer and fall seasons. The noncanonical relationship is caused by a longer (shorter) season associated with drier (wetter) ISM seasonal rainfall anomalies. A majority of these noncanonical seasons, with anomalously short season length but anomalously high seasonal mean rain, tend to occur under relatively weak La Nina forcing during the boreal summer season. Although the onset of such seasons occurs through canonical ENSO forcing of a large- scale meridional temperature gradient, the demise is dictated by the depletion of moist static energy from the underlying cooling of the upper ocean in the northern Indian Ocean. This is due to stronger meridional Ekman ocean heat transport forced by the stronger low- level atmospheric southwesterlies than those in the corresponding canonical wet ISM season.
Show less - Date Issued
- 2017-03
- Identifier
- FSU_libsubv1_wos_000395539100012, 10.1175/JCLI-D-16-0501.1
- Format
- Citation
- Title
- Dynamics of Hydrocarbon Vents.
- Creator
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Deep-C Consortium, Earth, Ocean and Atmospheric Science, Ecogig, Schmidt Ocean Institute, Johansen, Caroline, Shedd, William, Abichou, Tarek, Pineda-Garcia, Oscar, Silva,...
Show moreDeep-C Consortium, Earth, Ocean and Atmospheric Science, Ecogig, Schmidt Ocean Institute, Johansen, Caroline, Shedd, William, Abichou, Tarek, Pineda-Garcia, Oscar, Silva, Mauricio, MacDonald, Ian R.
Show less - Date Issued
- 2013-02
- Identifier
- FSU_HPUA_2015_038_AllHandsPoster_016
- Format
- Document (PDF)
- Title
- Quantifying variance due to temporal and spatial difference between ship and satellite winds.
- Creator
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May, J., Bourassa, Mark
- Abstract/Description
-
Ocean vector winds measured by SeaWinds can be validated with comparison in situ data that are within a certain time and space range to the satellite overpass. The total amount of random observational error is composed of two primary components, which are quantified in this study: the uncertainty associated with the data sets and the uncertainty associated with the temporal and/or spatial difference between two observations. The variance associated with a temporal difference, which can be...
Show moreOcean vector winds measured by SeaWinds can be validated with comparison in situ data that are within a certain time and space range to the satellite overpass. The total amount of random observational error is composed of two primary components, which are quantified in this study: the uncertainty associated with the data sets and the uncertainty associated with the temporal and/or spatial difference between two observations. The variance associated with a temporal difference, which can be translated into a spatial difference using Taylor's hypothesis, between two observations is initially examined in an idealized case that includes only Shipboard Automated Meteorological and Oceanographic System (SAMOS) 1 min data. The results show that the amount of variance in wind speed and direction increases as the time difference increases, while the amount of variance in wind speed increases and direction decreases with larger wind speeds. Collocated SeaWinds and SAMOS observations are used to determine the total amount of variance associated with a temporal (equivalent) difference from 0 to 60 min. For combined differences less than 25 min (equivalent) and the selected wind speed bins, the variance associated with the temporal and spatial difference is dominated by small changes in the wind speed distribution, and the sum of the observational errors is approximately 1.0 m2 s-12 (12 deg2) and 1.5 m2 s-2 (10 deg2) for wind speeds between 4 and 7 m s-1 and 7-12 m s-1. For larger combined differences, the observational error variance is no longer the dominant term; therefore, the total variance is seen to gradually increase with increasing time differences.
Show less - Date Issued
- 2011
- Identifier
- FSU_migr_coaps_pubs-0024, 10.1029/2010JC006931
- Format
- Citation
- Title
- The oceanic influence on the rainy season of Peninsular Florida.
- Creator
-
Misra, Vasubandhu, Mishra, Akhilesh
- Abstract/Description
-
In this study we show that the robust surface ocean currents around Peninsular Florida, namely, the Loop and the Florida Currents, affect the terrestrial wet season of Peninsular Florida. We show this through two novel regional coupled ocean-atmosphere models with different bathymetries that dislocate and modulate the strength of these currents and thereby affect the overlying sea surface temperature (SST) and upper ocean heat content. This study show that a weaker current system produces...
Show moreIn this study we show that the robust surface ocean currents around Peninsular Florida, namely, the Loop and the Florida Currents, affect the terrestrial wet season of Peninsular Florida. We show this through two novel regional coupled ocean-atmosphere models with different bathymetries that dislocate and modulate the strength of these currents and thereby affect the overlying sea surface temperature (SST) and upper ocean heat content. This study show that a weaker current system produces colder coastal SSTs along the Atlantic coast of Florida that reduces the length of the wet season and the total seasonal accumulation of precipitation over Peninsular Florida relative to the regional climate model simulation, in which these currents are stronger. The moisture budget reveals that as a result of these forced changes to the temperature of the upper coastal Atlantic Ocean, overlying surface evaporation and atmospheric convection is modulated. This consequently changes the moisture flux convergence leading to the modulation of the terrestrial wet season rainfall over Peninsular Florida that manifests in changes in the length and distribution of daily rain rate of the wet season. The results of this study have implications on interpreting future changes to hydroclimate of Peninsular Florida owing to climate change and low-frequency changes to the Atlantic meridional overturning circulation that comprises the Loop and the Florida Currents as part of its upper branch. he season
Show less - Date Issued
- 2016-07-16
- Identifier
- FSU_libsubv1_wos_000380730500012, 10.1002/2016JD024824
- Format
- Citation
- Title
- The sensitivity of southeastern United States climate to varying irrigation vigor.
- Creator
-
Selman, Christopher, Misra, Vasubandhu
- Abstract/Description
-
Four regional climate model runs centered on the Southeast United States (SEUS) assuming a crop growing season of May through October are irrigated at 25% (IRR25), 50% (IRR50), 75% (IRR75), and 100% (IRR100) of the root zone porosity to assess the sensitivity of the SEUS climate to irrigation. A fifth run, assuming no irrigation (CTL), is used as the basis for comparison. Across all IRR runs, it is found that there is a general reduction in seasonal mean precipitation over the irrigated cells...
Show moreFour regional climate model runs centered on the Southeast United States (SEUS) assuming a crop growing season of May through October are irrigated at 25% (IRR25), 50% (IRR50), 75% (IRR75), and 100% (IRR100) of the root zone porosity to assess the sensitivity of the SEUS climate to irrigation. A fifth run, assuming no irrigation (CTL), is used as the basis for comparison. Across all IRR runs, it is found that there is a general reduction in seasonal mean precipitation over the irrigated cells relative to CTL. This manifests as an increase in dry (0-1mm/d) days and reduction in>1mm/d rainfall events. A comparative moisture budget reveals that area-averaged precipitation over the irrigated cells displays a reduction in precipitation and runoff in IRR100 with a weaker reduction in IRR25. This is despite an increase in vertically integrated moisture convergence and local evaporation. We find that irrigation increases the lower atmospheric stability, which in turn reduces the convective rainfall over the irrigated areas. Seasonally averaged temperatures reduce over irrigated areas, with the intensity of the reduction increasing with irrigation vigor. This is largely attributed to a repartitioning of sensible heat flux into latent heat flux. There is also, however, a small increase of heat flow to deeper soil layers. Precipitation ahead of transient cold fronts is also reduced by irrigation as they pass over irrigated cells, owing to the increased stability in the lower troposphere. The intensity of this precipitation reduction becomes more intense as irrigation vigor increases. Lastly, heat waves in the SEUS are reduced in intensity over irrigated cells.
Show less - Date Issued
- 2016-07-16
- Identifier
- FSU_libsubv1_wos_000380730500007, 10.1002/2016JD025002
- Format
- Citation
- Title
- Isolating the Temperature Feedback Loop and Its Effects on Surface Temperature.
- Creator
-
Sejas, Sergio A., Cai, Ming
- Abstract/Description
-
Climate feedback processes are known to substantially amplify the surface warming response to an increase of greenhouse gases. When the forcing and feedbacks modify the temperature response they trigger temperature feedback loops that amplify the direct temperature changes due to the forcing and nontemperature feedbacks through the thermal-radiative coupling between the atmosphere and surface. This study introduces a new feedback-response analysis method that can isolate and quantify the...
Show moreClimate feedback processes are known to substantially amplify the surface warming response to an increase of greenhouse gases. When the forcing and feedbacks modify the temperature response they trigger temperature feedback loops that amplify the direct temperature changes due to the forcing and nontemperature feedbacks through the thermal-radiative coupling between the atmosphere and surface. This study introduces a new feedback-response analysis method that can isolate and quantify the effects of the temperature feedback loops of individual processes on surface temperature from their corresponding direct surface temperature responses. The authors analyze a 1% yr 21 increase of CO2 simulation of the NCAR CCSM4 at the time of CO2 doubling to illustrate the new method. The Planck sensitivity parameter, which indicates colder regions experience stronger surface temperature responses given the same change in surface energy flux, is the inherent factor that leads to polar warming amplification (PWA). This effect explains the PWA in the Antarctic, while the direct temperature response to the albedo and cloud feedbacks further explains the greater PWA of the Arctic. Temperature feedback loops, particularly the one associated with the albedo feedback, further amplify the Arctic surface warming relative to the tropics. In the tropics, temperature feedback loops associated with the CO2 forcing and water vapor feedback cause most of the surface warming. Overall, the temperature feedback is responsible for most of the surface warming globally, accounting for nearly 76% of the global-mean surface warming. This is 3 times larger than the next largest warming contribution, indicating that the temperature feedback loop is the preeminent contributor to the surface warming.
Show less - Date Issued
- 2016-08
- Identifier
- FSU_libsubv1_wos_000380764400018, 10.1175/JAS-D-15-0287.1
- Format
- Citation
- Title
- Mesoscale modeling for the rapid movement of monsoonal isochrones.
- Creator
-
Kumar, Vinay, Krishnamurti, T. N.
- Abstract/Description
-
The progresses of fast moving 2013 monsoonal isochrones were simulated with WRF model at 25 km and compared with slower moving isochrones of 2014. A large number of sensitivity experiments were performed by enhancing of soil moisture, stratiform rain up to 25%, their combination and reducing soil temperature by 12%, over 5 grid points to the north of the isochrones over a relatively dry soil layer. The modified soil parameters and startiform rain ahead of isochrones enhances the population of...
Show moreThe progresses of fast moving 2013 monsoonal isochrones were simulated with WRF model at 25 km and compared with slower moving isochrones of 2014. A large number of sensitivity experiments were performed by enhancing of soil moisture, stratiform rain up to 25%, their combination and reducing soil temperature by 12%, over 5 grid points to the north of the isochrones over a relatively dry soil layer. The modified soil parameters and startiform rain ahead of isochrones enhances the population of the buoyant elements, divergent flows of the local Hadley circulation normal to the isochrones; resulting in a fast movement of the isochrones.
Show less - Date Issued
- 2016-01
- Identifier
- FSU_libsubv1_wos_000369737200013, 10.1002/asl.617
- Format
- Citation
- Title
- Subinertial canyon resonance.
- Creator
-
Clarke, Allan J., Van Gorder, Stephen
- Abstract/Description
-
Near the bottom of a narrow canyon currents that oscillate back and forth along the bottom slope h(x) in a stratified ocean of buoyancy frequency N do so with a natural internal gravitational frequency Nh(x). From May 2012 to May 2013 Acoustic Doppler Current Profiler measurements were made at 715 m depth in the deep narrow part of the DeSoto Canyon south of Pensacola, Florida, in water with 2 pi/Nh(x) approximate to 2.5 days. Above the canyon the flow follows the large-scale isobaths, but...
Show moreNear the bottom of a narrow canyon currents that oscillate back and forth along the bottom slope h(x) in a stratified ocean of buoyancy frequency N do so with a natural internal gravitational frequency Nh(x). From May 2012 to May 2013 Acoustic Doppler Current Profiler measurements were made at 715 m depth in the deep narrow part of the DeSoto Canyon south of Pensacola, Florida, in water with 2 pi/Nh(x) approximate to 2.5 days. Above the canyon the flow follows the large-scale isobaths, but beneath the canyon rim the current oscillates along the canyon axis with 2-3 day periodicity, and is much stronger than and uncorrelated with the overlying flow. A simple theoretical model explains the resonant response. Published observations from the Hudson and Gully canyons suggest that the strong subinertial current oscillations observed in these canyons occur close to the relevant local frequency Nh(x), consistent with the proposed simple model physics.
Show less - Date Issued
- 2016-04-28
- Identifier
- FSU_libsubv1_wos_000378338800032, 10.1002/2016GL068258
- Format
- Citation
- Title
- Erosion Chennels at the DeSoto Canyon.
- Creator
-
Deep-C Consortium, Florida State University, Earth, Ocean and Atmospheric Science, National Ocean and Atmospheric Association, Silva, Mauricio, MacDonald, Ian
- Date Issued
- 2013-02
- Identifier
- FSU_HPUA_2015_038_AllHandsPoster_030
- Format
- Document (PDF)
- Title
- Pore water oxygen dynamics influenced by tarballs buried in permeable saturated sands.
- Creator
-
Deep-C Consortium, Earth, Ocean and Atmospheric Science, Florida State University, Huettel, Markus, Kostka, Joel
- Date Issued
- 2013-02
- Identifier
- FSU_HPUA_2015_038_AllHandsPoster_013
- Format
- Document (PDF)
- Title
- Poster Session: Geomorphic & Physical Oceanographic Processes.
- Creator
-
Deep-C Consortium, Gulf of Mexico Research Initiative, Clarke, Allan, Asl, Samira Daneshgar, Johansen, Caroline, Locker, Stan, MacDonald, Ian, Jaimes, Benjamin, Silva, Mauricio,...
Show moreDeep-C Consortium, Gulf of Mexico Research Initiative, Clarke, Allan, Asl, Samira Daneshgar, Johansen, Caroline, Locker, Stan, MacDonald, Ian, Jaimes, Benjamin, Silva, Mauricio, Wienders, Nico
Show less - Date Issued
- 2013-02-27
- Identifier
- FSU_HPUA_2015_038_AllHandsFeb_008
- Format
- Document (PDF)
- Title
- The Gulf of mexico Coupled Regional Modeling System.
- Creator
-
Deep-C Consortium, Center for Ocean-Atmospheric Prediction Studies, Velissariou, Panagiotis, Hannah, Hannah R., Morey, Steve L., Chassignet, Eric P.
- Date Issued
- 2013-02
- Identifier
- FSU_HPUA_2015_038_AllHandsPoster_011
- Format
- Document (PDF)
- Title
- Preliminary Assessment of Sediment Macrofaunal Community Structure in Desoto Canyon, Following the Horizon Oil Spill.
- Creator
-
Deep-C Consortium, Baco, Amy R., Shantharam, Arvind K., Wei, Chih-Lin, Rowe, Gilbert
- Date Issued
- 2013-09-11
- Identifier
- FSU_HPUA_2015_038_AllHandsSept_002
- Format
- Document (PDF)
- Title
- Methane Production in the Oceanic Photic Zone: Microbial Community Structure and Function.
- Creator
-
Deep-C Consortium, Florida State University, Earth, Ocean and Atmosphere Science, Mason, Olivia, Rakowski, Chrissie, Chanton, Jeff
- Date Issued
- 2013-02
- Identifier
- FSU_HPUA_2015_038_AllHandsPoster_021
- Format
- Document (PDF)
- Title
- Characterizing the onset and demise of the Indian summer monsoon.
- Creator
-
Noska, Ryne, Misra, Vasubandhu
- Abstract/Description
-
An objective index of the onset and demise of the Indian summer monsoon (ISM) is introduced. This index has the advantage of simplicity by using only one variable, which is the spatially averaged all-India rainfall, a reliably observed quantity for more than a century. The proposed onset index is shown to be insensitive to all historic false onsets. By definition, now the seasonal mean rainfall anomalies become a function of variations in onset and demise dates, rendering their monitoring to...
Show moreAn objective index of the onset and demise of the Indian summer monsoon (ISM) is introduced. This index has the advantage of simplicity by using only one variable, which is the spatially averaged all-India rainfall, a reliably observed quantity for more than a century. The proposed onset index is shown to be insensitive to all historic false onsets. By definition, now the seasonal mean rainfall anomalies become a function of variations in onset and demise dates, rendering their monitoring to be very meaningful. This new index provides a comprehensive representation of the seasonal evolution of the ISM by capturing the corresponding changes in large-scale dynamic and thermodynamic variables. We also show that the interannual variability of the onset date of the ISM is associated with El Nino-Southern Oscillation (ENSO) with early (late) onsets preceded by cold (warm) ENSO.
Show less - Date Issued
- 2016-05-16
- Identifier
- FSU_libsubv1_wos_000378339200057, 10.1002/2016GL068409
- Format
- Citation
- Title
- Structural Emplacement and Stratigraphic Setting of Eastern Blue Ridge Plutonic Complexes and Associated Lithologies, Alabama Appalachians.
- Creator
-
Pazel, John, Department of Earth, Ocean and Atmospheric Sciences, Florida State University
- Abstract/Description
-
pending
- Date Issued
- 2012
- Identifier
- FSU_migr_etd-5101
- Format
- Thesis
- Title
- Metagenomic Insights Supporting Microbial Community Succession in Contaminated Gulf Beach Sands.
- Creator
-
Deep-C Consortium, Florida State University, Earth, Ocean and Atmosphere Science, Georgia Institute of Technology, Marks, Kala P., Overholt, Will A., Rodriguez-R, Luis M.,...
Show moreDeep-C Consortium, Florida State University, Earth, Ocean and Atmosphere Science, Georgia Institute of Technology, Marks, Kala P., Overholt, Will A., Rodriguez-R, Luis M., Konstantinidis, Kostas, Canion, Andy, Kaba, John, Hagan, Chris, Huettel, Markus, Kostka, Joel E.
Show less - Date Issued
- 2013-02
- Identifier
- FSU_HPUA_2015_038_AllHandsPoster_020
- Format
- Document (PDF)
- Title
- Understanding wet season variations over Florida.
- Creator
-
Misra, Vasubandhu, DiNapoli, Steven
- Abstract/Description
-
The wet season of Florida is well defined and is invariably centered in the boreal summer season of June–July–August. In this observational study we objectively define the Length of the Wet Season (LOWS) for Florida and examine its variations with respect to El Niño and the Southern Oscillation (ENSO) and the Atlantic Warm Pool (AWP). Our study reveals that ENSO variability has a profound influence on the LOWS especially over south Florida and parts of panhandle Florida prior to 1976. In the...
Show moreThe wet season of Florida is well defined and is invariably centered in the boreal summer season of June–July–August. In this observational study we objectively define the Length of the Wet Season (LOWS) for Florida and examine its variations with respect to El Niño and the Southern Oscillation (ENSO) and the Atlantic Warm Pool (AWP). Our study reveals that ENSO variability has a profound influence on the LOWS especially over south Florida and parts of panhandle Florida prior to 1976. In the post-1976 era the influence of ENSO has significantly diminished. Our results show that in this pre-1976 era, warm (cold) ENSO events in the boreal winter are followed by long (short) LOWS over the region. This variation is consistent with warm (cold) ENSO events influencing early (late) onset of the wet season in the region. There is significant relationship of the LOWS in south and northeast Florida with the variation of the AWP. Unlike the teleconnection with ENSO the relationship of the demise of the wet season with AWP is stronger in the post-1976 period compared to the pre-1976 period. Furthermore the variability of the LOWS has increased in the post-1976 period.
Show less - Date Issued
- 2012
- Identifier
- FSU_migr_coaps_pubs-0056, 10.1007/s00382-012-1382-4
- Format
- Citation
- Title
- A latent heat retrieval and its effects on the intensity and structure change of Hurricane Guillermo (1997). Part I: the algorithm and observations.
- Creator
-
Guimond, S., Bourassa, Mark, Reasor, Paul
- Abstract/Description
-
Despite the fact that latent heating in cloud systems drives many atmospheric circulations, including tropical cyclones, little is known of its magnitude and structure, largely because of inadequate observations. In this work, a reasonably high-resolution (2 km), four-dimensional airborne Doppler radar retrieval of the latent heat of condensation/evaporation is presented for rapidly intensifying Hurricane Guillermo (1997). Several advancements in the basic retrieval algorithm are shown,...
Show moreDespite the fact that latent heating in cloud systems drives many atmospheric circulations, including tropical cyclones, little is known of its magnitude and structure, largely because of inadequate observations. In this work, a reasonably high-resolution (2 km), four-dimensional airborne Doppler radar retrieval of the latent heat of condensation/evaporation is presented for rapidly intensifying Hurricane Guillermo (1997). Several advancements in the basic retrieval algorithm are shown, including 1) analyzing the scheme within the dynamically consistent framework of a numerical model, 2) identifying algorithm sensitivities through the use of ancillary data sources, and 3) developing a precipitation budget storage term parameterization. The determination of the saturation state is shown to be an important part of the algorithm for updrafts of -5 m s -1 or less. The uncertainties in the magnitude of the retrieved heating are dominated by errors in the vertical velocity. Using a combination of error propagation and Monte Carlo uncertainty techniques, biases are found to be small, and randomly distributed errors in the heating magnitude are ~16% for updrafts greater than 5 m s -1 and ~156% for updrafts of 1 m s -1. Even though errors in the vertical velocity can lead to large uncertainties in the latent heating field for small updrafts/downdrafts, in an integrated sense the errors are not as drastic. In Part II, the impact of the retrievals is assessed by inserting the heating into realistic numerical simulations at 2-km resolution and comparing the generated wind structure to the Doppler radar observations of Guillermo.
Show less - Date Issued
- 2011
- Identifier
- FSU_migr_coaps_pubs-0018, 10.1175/2011JAS3700.1
- Format
- Citation
- Title
- Analysis of Observations to Understand the Physics of the Connectivity Between the Deep Sea and the Coast Through the DeSoto Canyon.
- Creator
-
Deep-C Consortium, Clarke, Allan J., Van Gorder, Stephen, Wienders, Nicolas, Hamilton, Peter, Speer, Kevin
- Date Issued
- 2013-09-10
- Identifier
- FSU_HPUA_2015_038_AllHandsSept_005
- Format
- Document (PDF)
- Title
- Stable isotope tracing of methylmercury production and bioaccumulation in the Northern Gulf of Mexico food web.
- Creator
-
Deep-C Consortium, Florida State University, Harper, Alexandra, Chanton, Jeffery, Wilson-Younge, Rachel
- Date Issued
- 2013-02
- Identifier
- FSU_HPUA_2015_038_AllHandsPoster_010
- Format
- Document (PDF)
- Title
- Using Natural Radon (222 Rn) as a Tracer of Groundwater Discharge into Lake Bradford.
- Creator
-
Compare, Kyle Alexander
- Abstract/Description
-
Due to its elevated abundance in groundwater relative to surface waters, lack of chemical activity, and short half-life, natural radon (222Rn) may be used as an effective tracer of groundwater discharge into lakes. A steady-state radon mass balance was applied to estimate the groundwater flux to Lake Bradford, Florida. It is assumed that the lake is well mixed, only has radon input from groundwater advection, and only loses radon due to radioactive decay and atmospheric evasion. A RAD7 radon...
Show moreDue to its elevated abundance in groundwater relative to surface waters, lack of chemical activity, and short half-life, natural radon (222Rn) may be used as an effective tracer of groundwater discharge into lakes. A steady-state radon mass balance was applied to estimate the groundwater flux to Lake Bradford, Florida. It is assumed that the lake is well mixed, only has radon input from groundwater advection, and only loses radon due to radioactive decay and atmospheric evasion. A RAD7 radon detector with an RAD AQUA attachment were used to make radon measurements of the lake water, as well as radon diffusion from sediment, and radon-in-air. A temperature probe was used to account for water temperature and measurements from an on-site weather station was used to account for wind speed. It was found that there was only 776 m3 / day of groundwater discharge into the lake. Since the lake is over a million cubic meters in volume, this was a surprisingly small amount and suggests that groundwater discharge was especially low during our measurement period or that the lake is primarily influenced through precipitation. We propose two opposing hypotheses to explain these observations: (1) the water table was low during our measurements resulting in a reduced hydraulic head; or (2) this lake is primarily recharged through direct precipitation and surface runoff. Further radon monitoring at various times throughout a hydrologic year would develop a better understanding on the groundwater dynamics of Lake Bradford.
Show less - Date Issued
- 2018-04-24
- Identifier
- FSU_libsubv1_scholarship_submission_1524614083_d68d8045
- Format
- Thesis
- Title
- Mississippi River Plume Enriches Microbial Diversity In The Northern Gulf Of Mexico.
- Creator
-
Mason, Olivia U., Canter, Erin J., Gillies, Lauren E., Paisie, Taylor K., Roberts, Brian J.
- Abstract/Description
-
The Mississippi River (MR) serves as the primary source of freshwater and nutrients to the northern Gulf of Mexico (nGOM). Whether this input of freshwater also enriches microbial diversity as the MR plume migrates and mixes with the nGOM serves as the central question addressed herein. Specifically, in this study physicochemical properties and planktonic microbial community composition and diversity was determined using iTag sequencing of 16S rRNA genes in 23 samples collected along a...
Show moreThe Mississippi River (MR) serves as the primary source of freshwater and nutrients to the northern Gulf of Mexico (nGOM). Whether this input of freshwater also enriches microbial diversity as the MR plume migrates and mixes with the nGOM serves as the central question addressed herein. Specifically, in this study physicochemical properties and planktonic microbial community composition and diversity was determined using iTag sequencing of 16S rRNA genes in 23 samples collected along a salinity (and nutrient) gradient from the mouth of the MR, in the MR plume, in the canyon, at the Deepwater Horizon wellhead and out to the loop current. Analysis of these datasets revealed that the MR influenced microbial diversity as far offshore as the Deepwater Horizon wellhead. The MR had the highest microbial diversity, which decreased with increasing salinity. MR bacterioplankton communities were distinct compared to the nGOM, particularly in the surface where Actinobacteria and Proteobacteria dominated, while the deeper MR was also enriched in Thaumarchaeota. Statistical analyses revealed that nutrients input by the MR, along with salinity and depth, were the primary drivers in structuring the microbial communities. These results suggested that the reduced salinity, nutrient enriched MR plume could act as a seed bank for microbial diversity as it mixes with the nGOM. Whether introduced microorganisms are active at higher salinities than freshwater would determine if this seed bank for microbial diversity is ecologically significant. Alternatively, microorganisms that are physiologically restricted to freshwater habitats that are entrained in the plume could be used as tracers for freshwater input to the marine environment.
Show less - Date Issued
- 2016-07-07
- Identifier
- FSU_libsubv1_wos_000379120100001, 10.3389/fmicb.2016.01048
- Format
- Citation
- Title
- Seafood And Beach Safety In The Aftermath Of The Deepwater Horizon Oil Spill.
- Creator
-
Dickey, Robert, Huettel, Markus
- Abstract/Description
-
The 2010 explosion and sinking of the Deepwater Horizon oil platform in the Gulf of Mexico resulted in the largest oil spill the United States has ever endured. The oil spill raised many public health and environmental concerns, including those about the safety of Gulf seafood and public beaches. Analysis of seafood and coastal beaches in the aftermath of the oil spill indicated that public health risks from exposure to harmful crude oil residues returned to pre-spill levels soon after the...
Show moreThe 2010 explosion and sinking of the Deepwater Horizon oil platform in the Gulf of Mexico resulted in the largest oil spill the United States has ever endured. The oil spill raised many public health and environmental concerns, including those about the safety of Gulf seafood and public beaches. Analysis of seafood and coastal beaches in the aftermath of the oil spill indicated that public health risks from exposure to harmful crude oil residues returned to pre-spill levels soon after the oil spill had dissipated. However, the official seafood risk assessment elicited concerns about the inclusion of vulnerable populations, and gaps in toxicological knowledge and related risk information about many of the harmful components in crude oil. Residual crude oil may persist in water-saturated sediments and submerged oil mats that can act as sources for remobilization and future exposures. The response to the Deepwater Horizon event revealed a lack of adequate demographic and human health baseline data, benchmark environmental contaminant data, effective risk communication strategies, and integrated surveillance systems linking human and environmental health status and trends. The development of such knowledge would help improve responses and outcomes to future large-scale catastrophic events.
Show less - Date Issued
- 2016-09
- Identifier
- FSU_libsubv1_wos_000382334500025, 10.5670/oceanog.2016.83
- Format
- Citation