Oceanography and Atmospheric Sciences and Meteorology Commons^™

A Polarimetric Radar Analysis Of Cold- And Warm-Based Supercells, Timothy J. Gunkel

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Polarimetric analyses of supercell thunderstorms have been increasingly common within the past decade, since operational polarimetric radar data became available in 2013. Although polarimetric signatures within supercell thunderstorms are well known, few have investigated variability in these signatures in differing environments. Polarimetric signatures can provide vital information regarding the microphysical characteristics and processes in supercell thunderstorms. Specific polarimetric signatures of interest are the differential reflectivity (Z_DR) column, the low-level polarimetrically inferred hail core, and the Z_DR arc. These signatures provide information regarding updraft characteristics, hailfall characteristics, and size sorting processes in the storm- relative inflow. Previous studies …

Phytoplankton And Carbon Dynamics In The Estuarine-Coastal Waters Of The Northern Gulf Of Mexico From Field Data And Ocean Color Remote Sensing, Bingqing Liu

LSU Doctoral Dissertations

In this study, phytoplankton community and carbon dynamics were examined in the optically complex estuarine-coastal regions of the northern Gulf of Mexico (nGOM) from field and satellite ocean color observations. As part of this study, bio-optical ocean color algorithms for i) dissolved organic carbon (DOC), ii) phytoplankton pigment composition, iii) adaptive estimation of Chl a and iv) phytoplankton size fractions were developed to facilitate the study of biogeochemical cycling in the nGOM.

The phytoplankton based algorithms were applied to Sentinel 3A/B-OLCI oean color data to assess phytoplankton community dynamics to extreme river discharge conditions as well as hurricanes in the …

Changes In Atmospheric, Meteorological, And Ocean Parameters Associated With The 12 January 2020 Taal Volcanic Eruption, Feng Jing, Akshansa Chauhan, Ramesh P. Singh, Prasanjit Dash

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The Taal volcano erupted on 12 January 2020, the first time since 1977. About 35 mild earthquakes (magnitude greater than 4.0) were observed on 12 January 2020 induced from the eruption. In the present paper, we analyzed optical properties of volcanic aerosols, volcanic gas emission, ocean parameters using multi-satellite sensors, namely, MODIS (Moderate Resolution Imaging Spectroradiometer), AIRS (Atmospheric Infrared Sounder), OMI (Ozone Monitoring Instrument), TROPOMI (TROPOspheric Monitoring Instrument) and ground observations, namely, Argo, and AERONET (AErosol RObotic NETwork) data. Our detailed analysis shows pronounced changes in all the parameters, which mainly occurred in the western and south-western regions because the …

Microbial Symbionts And Ecological Divergence Of Caribbean Sponges: A New Perspective On An Ancient Association, Christopher Freeman, Cole Easson, Kenan O. Matterson, Robert W. Thacker, David M. Baker, Valerie J. Paul

Marine & Environmental Sciences Faculty Articles

Marine sponges host diverse communities of microbial symbionts that expand the metabolic capabilities of their host, but the abundance and structure of these communities is highly variable across sponge species. Specificity in these interactions may fuel host niche partitioning on crowded coral reefs by allowing individual sponge species to exploit unique sources of carbon and nitrogen, but this hypothesis is yet to be tested. Given the presence of high sponge biomass and the coexistence of diverse sponge species, the Caribbean Sea provides a unique system in which to investigate this hypothesis. To test for ecological divergence among sympatric Caribbean sponges …

Testing The Efficacy Of Recompression Tools To Reduce The Discard Mortality Of Reef Fishes In The Gulf Of Mexico, Oscar E. Ayala

USF Tampa Graduate Theses and Dissertations

In order to enhance the recovery of overfished stocks, fishery managers have implemented increasingly restrictive harvest regulations. However, discarded fish are susceptible to mortality from barotrauma when retrieved from depth. Venting tools are commonly used to enable fish to return to their depth of capture. An alternative method has been developed that involves the rapid descent of fish to their depth of capture to reduce buoyancy. In the Gulf of Mexico, the released portion of Red Snapper (Lutjanus campechanus) and Red Grouper (Epinephelus morio) has exceeded 80% of total catch. I tested the survival of these two economically important species …

Methanethiol, Dimethyl Sulfide And Acetone Over Biologically Productive Waters In The Southwest Pacific Ocean, Sarah J. Lawson, Cliff S. Law, Mike J. Harvey, Thomas G. Bell, Carolyn F. Walker, Warren J. De Bruyn, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Atmospheric methanethiol (MeSH_a), dimethyl sulfide (DMS_a) and acetone (acetone_a) were measured over biologically productive frontal waters in the remote southwest Pacific Ocean in summertime 2012 during the Surface Ocean Aerosol Production (SOAP) voyage. MeSH_a mixing ratios varied from below the detection limit (< 10 ppt) up to 65 ppt and were 3 %–36 % of parallel DMS_a mixing ratios. MeSH_a and DMS_a were correlated over the voyage (R²=0.3, slope = 0.07) with a stronger correlation over a coccolithophore-dominated phytoplankton bloom (R²=0.5, slope 0.13). The diurnal cycle for MeSH_a shows similar behaviour to DMS_a with mixing ratios …

Antibiotic Resistance In Marine Microbial Communities Proximal To A Florida Sewage Outfall System, Dale W. Griffin, Kenneth Banks, Kurtis Gregg, Sarah Shedler, Brian K. Walker

Marine & Environmental Sciences Faculty Articles

Water samples were collected at several wastewater treatment plants in southeast Florida, and water and sediment samples were collected along and around one outfall pipe, as well as along several transects extending both north and south of the respective outfall outlet. Two sets of samples were collected to address potential seasonal differences, including 38 in the wet season (June 2018) and 42 in the dry season (March 2019). Samples were screened for the presence/absence of 15 select antibiotic resistance gene targets using the polymerase chain reaction. A contrast between seasons was found, with a higher frequency of detections occurring in …

Light Organ Photosensitivity In Deep-Sea Shrimp May Suggest A Novel Role In Counterillumination, Heather D. Bracken-Grissom, Danielle M. Deleo, Megan L. Porter, Tom Iwanicki, Jamie E. Sickles, Tamara Frank

Marine & Environmental Sciences Faculty Articles

Extraocular photoreception, the ability to detect and respond to light outside of the eye, has not been previously described in deep-sea invertebrates. Here, we investigate photosensitivity in the bioluminescent light organs (photophores) of deep-sea shrimp, an autogenic system in which the organism possesses the substrates and enzymes to produce light. Through the integration of transcriptomics, in situ hybridization and immunohistochemistry we find evidence for the expression of opsins and phototransduction genes known to play a role in light detection in most animals. Subsequent shipboard light exposure experiments showed ultrastructural changes in the photophore similar to those seen in crustacean eyes, …

Investigation Of Retention Versus Export Of Planktonic Fish Eggs In The Northeastern Gulf Of Mexico, Bich Vi Viviane Nguyen

USF Tampa Graduate Theses and Dissertations

Planktonic fish eggs can be reliably identified with DNA barcoding, and their distribution and abundance can be monitored. Passive drifting fish eggs can be advected by ocean currents and as a result, can either be locally retained or exported away from the West Florida Shelf (WFS). Investigating their retention or export helps in the interpretation of egg abundance trends and in understanding their distribution in long-term surveys. The present investigation was performed in two steps using a combination of biological and physical oceanographic methods. First, fish fecundity of three species (Red Snapper, Vermilion Snapper, and Sand Perch) was assessed, first, …

What Is The Most Threatening Disaster To The Continental United States?, Aaron Spomer, Elijah Kaufman, Julisa Prieto-Garcia, Brooke Aschwanden

UNO Student Research and Creative Activity Fair

Our goal for our project is to fully understand which natural disaster is the most destructive to the United States. We have chosen to compare hurricanes, floods, tornadoes, wildfires, earthquakes, and nor’easters. We have researched the cost of the total damage and repair, how the warning systems have improved over time, the death tolls from each, and also the frequency at which each one occurs. Each group member will research a different disaster impact, and the data will create a comprehensive view of the level of devastation each disaster has. We collected data all the way from the early 1900s …

Weather And Climate Summary And Forecast: March 2020 Report, Gregory V. Jones

Linfield University Wine Studies Reports

This report provides a summary of the weather and climate forecast for March 2020. It includes forecast information specific to the Pacific Northwest and the western United States, as well as forecast information for other portions of the United States and abroad.

Reproductive Ecology Of Dragonfishes (Stomiiformes: Stomiidae) In The Gulf Of Mexico, Alex Marks, David Kerstetter, David Wyanski, Tracey Sutton

Marine & Environmental Sciences Faculty Articles

The most abundant fishes on Earth live in the meso- and bathypelagic (deep-pelagic, collectively) zones of the open ocean, where they play a key role in deep-sea food webs by mediating energy flow from surface waters to great depth. Of these fishes, the most speciose taxon is the family Stomiidae (dragonfishes). Despite being the numerically dominant predators of the global mesopelagic zone, stomiid reproductive ecology is poorly known. Research surveys rarely catch larger adults, impeding reproductive ecology studies. Between 2010 and 2011, the Offshore Nekton Sampling and Analysis Program sampled the Gulf of Mexico using a research-sized, opening/closing trawl (10-m …

Effect Of Channelized And Unchannelized Lateral Outflow On Three-Dimensional Flow Structure And Sediment Transport Mechanisms In A River Delta, Mohammad Kifayath Chowdhury

LSU Master's Theses

Spatial and temporal patterns in three-dimensional flow structure have been linked to channel morphology and processes in many environments, including river meander bends, confluences-diffluences, and bedrock canyons. However, there is not yet an understanding of how channelized and gradual, distributed lateral outflows that are often prevalent in deltaic distributary systems influence three-dimensional flow structure and sediment transport mechanisms. This thesis presents an analysis of 3D flow structure data collected from Wax Lake Delta, a naturally developing river-dominated delta in the northern Gulf of Mexico. Three hydrographic surveys were conducted using boat-mounted acoustic Doppler current profiler (ADCP) at two sites: an …

Utilizing Objective Drought Severity Thresholds To Improve Drought Monitoring, Zachary T. Leasor, Steven M. Quiring, Mark D. Svoboda

National Drought Mitigation Center: Faculty Publications

Drought is a prominent climatic hazard in the south-central United States. Drought severity is frequently classified using the categories established by the U.S. Drought Monitor (USDM). This study evaluates whether the thresholds for the standardized precipitation index (SPI) used by the USDM accurately classify drought severity. This study uses the SPI based on PRISM precipitation data from 1900 to 2015 to evaluate drought severity in Texas, Oklahoma, and Kansas. The results show that the fixed SPI thresholds for the USDM drought categories may lead to a systematic underestimation of drought severity in arid regions. To address this issue, objective drought …

Rockhounding, Seafaring, And Other Material Tales For The End Of The World, Noemie Fortin

The Goose

In the face of accelerated environmental degradation and climate instability, the future of the Earth and of all life on earth is difficult to visualize. Therefore, the different mediums through which we consider environmental issues are just as important as the actions we take to address them. Focusing on three projects combining art, science, and activism, this article suggests a compilation of material tales. They tell stories of plastic rocks and aluminum nuggets where the protagonists are partly finely crafted objects, partly waste materials, and sometimes both at once. Artists Kelly Jazvac, Yesenia Thibeault-Picazo, and the collective Studio Swine collaborate …

Marine Carbonyl Sulfide (Ocs) And Carbon Disulfide (Cs2): A Compilation Of Measurements In Seawater And The Marine Boundary Layer, Sinikka T. Lennartz, Christa A. Marandino, Marc Von Hobe, Meinrat O. Andreae, Kazushi Aranami, Elliot Atlas, Max Berkelhammer, Heinz Bingemer, Dennis Booge, Gregory A. Cutter, Pau Cortes, Stefanie Kremser, Cliff S. Law, Andrew Marriner, Rafel Simó, Birgit Quack, Günther Uher, Huixiang Xie, Xiaobin Xu

OES Faculty Publications

Carbonyl sulfide (OCS) and carbon disulfide (CS₂) are volatile sulfur gases that are naturally formed in seawater and exchanged with the atmosphere. OCS is the most abundant sulfur gas in the atmosphere, and CS₂ is its most important precursor. They have attracted increased interest due to their direct (OCS) or indirect (CS₂ via oxidation to OCS) contribution to the stratospheric sulfate aerosol layer. Furthermore, OCS serves as a proxy to constrain terrestrial CO₂uptake by vegetation. Oceanic emissions of both gases contribute a major part to their atmospheric concentration. Here we present a database of …

Detection Of Reconnection Signatures In Solar Flares, Taylor R. Whitney

Theses and Dissertations

Solar flare forecasting is limited by the current understanding of mechanisms that govern magnetic reconnection, the main physical phenomenon associated with these events. As a result, forecasting relies mainly on climatological correlations to historical events rather than the underlying physics principles. Solar physics models place the neutral point of the reconnection event in the solar corona. Correspondingly, studies of photospheric magnetic fields indicate changes during solar flares -- particularly in relation to the field helicity -- on the solar surface as a result of the associated magnetic reconnection. This study utilizes data from the Solar Dynamics Observatory (SDO) Helioseismic and …

Modulation Of Lightning Occurrence By The Solar Wind, Adam L. Baxter

Theses and Dissertations

Lightning affects military and civilian operations. Characterization of the distribution of global lightning strikes of two detection networks based on solar wind events is analyzed. the median analysis by latitude gave different results for the two network datasets. The KLD pulled out some common features such as the seasonal dependence and a general increase in lightning at the equator. Comparisons between different datasets must be handled carefully. the KLD method may be a way to capture common features, or assess how similar the datasets are. A detailed analysis of the differences between the tow networks detection algorithms and investigating other …

2020 March - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

No abstract provided.

Determining Bulk Aerosol Absorption From Off Axis Backscattering Using Rayleigh Beacon Laser Pulses, Julie C. Grossnickle

Theses and Dissertations

Aerosol absorption and scattering can play a key role in degrading high energy laser performance in the form of thermal blooming and beam attenuation. Aerosol absorption properties are not completely understood, and thus affect how we are able to quantify expected high energy laser weapon performance. The Air Force Institute of Technology Center for Directed Energy (AFIT CDE) developed both Laser Environmental Effects Definition and Reference (LEEDR) and the High Energy Laser End-to-End Operational Simulation (HELEEOS) code to characterize atmospheric radiative transfer effects and evaluate expected directed energy weapon system performance. These packages enable modeling of total irradiance at given …