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Articles 31 - 60 of 114

Full-Text Articles in Other Oceanography and Atmospheric Sciences and Meteorology

Data Fusion And Synergy Of Active And Passive Remote Sensing; An Application For Freeze Thaw Detections, Zahra Sharifnezhadazizi Jan 2022

Data Fusion And Synergy Of Active And Passive Remote Sensing; An Application For Freeze Thaw Detections, Zahra Sharifnezhadazizi

Dissertations and Theses

There has been a recent evolvement in the field of remote sensing after increase of number satellites and sensors data which could be fused to produce new data and products. These efforts are mainly focused on using of simultaneous observations from different platforms with different spatial and temporal resolutions. The research dissertation aims to enhance the synergy use of active and passive microwave observations and examine the results in detection land freeze and thaw (FT) predictions. Freeze thaw cycles particularly in high-latitude regions have a crucial role in many applications such as agriculture, biogeochemical transitions, hydrology and ecosystem studies. The …


Atlantic Ocean Variability And European Alps Winter Precipitation, Giuseppe Formetta, Jonghun Kam, Sahar Sadeghi, Glenn Tootle, Thomas Piechota Nov 2021

Atlantic Ocean Variability And European Alps Winter Precipitation, Giuseppe Formetta, Jonghun Kam, Sahar Sadeghi, Glenn Tootle, Thomas Piechota

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Winter precipitation (snowpack) in the European Alps provides a critical source of freshwater to major river basins such as the Danube, Rhine, and Po. Previous research identified Atlantic Ocean variability and hydrologic responses in the European Alps. The research presented here evaluates Atlantic Sea Surface Temperatures (SSTs) and European Alps winter precipitation variability using Singular Value Decomposition. Regions in the north and mid-Atlantic from the SSTs were identified as being tele-connected with winter precipitation in the European Alps. Indices were generated for these Atlantic SST regions to use in prediction of precipitation. Regression and non-parametric models were developed using the …


Radiocarbon Analyses Quantify Peat Carbon Losses With Increasing Temperature In A Whole Ecosystem Warming Experiment, Rachel M. Wilson, Natalie A. Griffiths, Ate Visser, Karis J. Mcfarlane, Stephen D. Sebestyen, Keith C. Oleheiser, Samantha Bosman, Anya M. Hopple, Malak M. Tfaily, Randall K. Kolka, Paul J. Hanson, Joel E. Kostka, Scott D. Bridgham, Jason K. Keller, Jeffrey P. Chanton Oct 2021

Radiocarbon Analyses Quantify Peat Carbon Losses With Increasing Temperature In A Whole Ecosystem Warming Experiment, Rachel M. Wilson, Natalie A. Griffiths, Ate Visser, Karis J. Mcfarlane, Stephen D. Sebestyen, Keith C. Oleheiser, Samantha Bosman, Anya M. Hopple, Malak M. Tfaily, Randall K. Kolka, Paul J. Hanson, Joel E. Kostka, Scott D. Bridgham, Jason K. Keller, Jeffrey P. Chanton

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Climate warming is expected to accelerate peatland degradation and release rates of carbon dioxide (CO2) and methane (CH4). Spruce and Peatlands Responses Under Changing Environments is an ecosystem-scale climate manipulation experiment, designed to examine peatland ecosystem response to climate forcings. We examined whether heating up to +9 °C to 3 m-deep in a peat bog over a 7-year period led to higher C turnover and CO2 and CH4 emissions, by measuring 14C of solid peat, dissolved organic carbon (DOC), CH4, and dissolved CO2 (DIC). DOC, a major substrate for heterotrophic respiration, increased significantly with warming. There was no 7-year trend …


Analysis Of The Vertical Movement Of Active Gnss Stations As A Result Of Semidiurnal Tides, Rose Pearson, Eugen Niculae Sep 2021

Analysis Of The Vertical Movement Of Active Gnss Stations As A Result Of Semidiurnal Tides, Rose Pearson, Eugen Niculae

Conference papers

Ireland is subject to the constant effects and influence of semidiurnal tides. Western coastal regions are exposed to tidal ranges up to and exceeding five metres, consequentially introducing varied water volumes with temporal intervals. In addition, the Earth is elastic in composition, resulting in morphing and warping at the hands of celestial and oceanic forces.

This study looked at Online Precise Point Positioning (PPP) service to accurately monitor the vertical movement of coastal lands. In addition, GNSS Static Post-processing was conducted to discern which method of the global navigation satellite system (GNSS) processing is best for detecting VLM (vertical land …


Characterizing The Northern Hemisphere Circumpolar Vortex Through Space And Time, Nazla Bushra May 2021

Characterizing The Northern Hemisphere Circumpolar Vortex Through Space And Time, Nazla Bushra

LSU Doctoral Dissertations

This hemispheric-scale, steering atmospheric circulation represented by the circumpolar vortices (CPVs) are the middle- and upper-tropospheric wind belts circumnavigating the poles. Variability in the CPV area, shape, and position are important topics in geoenvironmental sciences because of the many links to environmental features. However, a means of characterizing the CPV has remained elusive. The goal of this research is to (i) identify the Northern Hemisphere CPV (NHCPV) and its morphometric characteristics, (ii) understand the daily characteristics of NHCPV area and circularity over time, (iii) identify and analyze spatiotemporal variability in the NHCPV’s centroid, and (iv) analyze how CPV features relate …


Microplankton Dynamics In The River-Dominated Mississippi Bight, Adam D. Boyette May 2021

Microplankton Dynamics In The River-Dominated Mississippi Bight, Adam D. Boyette

Dissertations

The Mississippi Bight (MSB) is a river-dominated continental margin influenced by multiple large river systems, including the Mississippi River, Alabama and Tombigbee rivers via Mobile Bay, and numerous smaller rivers, creeks, and bayous. This is part of a biologically-rich ecosystem that supports the second largest fishery industry by volume in the United States. Despite our understanding of the linkages between primary production with higher trophic levels, there remains limited studies quantifying these trophic interactions in this system. Microplankton (µm) community dynamics and trophic connectivity between primary producers and heterotrophic protists represent a critical nexus influencing overall biological productivity in this …


Characterization Of Uranium, Lead, And Rare Earth Element Pollution In Natural Soils And Sediments, Hope Rasmussen Apr 2021

Characterization Of Uranium, Lead, And Rare Earth Element Pollution In Natural Soils And Sediments, Hope Rasmussen

Civil and Environmental Engineering Theses and Dissertations

Heavy metals in the environment add to the global burden of pollution, negatively impacting public health and ecosystem resilience. This study included projects regarding uranium (U), lead (Pb), and rare earth elements (REE) in natural samples, due to their known toxicity, ubiquity, and relevance in context to recent pollution trends. The first project focused on testing the potential of using a hydroxyapatite product as a remediation solution for U-contaminated groundwater and soil at an EPA Superfund site. The results showed that the U was sequestered in a highly crystalline mineral form within the solids, guiding the EPA to specify the …


Microbially Induced Sedimentary Structures In Clastic Deposits: Implication For The Prospection For Fossil Life On Mars, Nora Noffke Jan 2021

Microbially Induced Sedimentary Structures In Clastic Deposits: Implication For The Prospection For Fossil Life On Mars, Nora Noffke

OES Faculty Publications

Abundant and well-preserved fossil microbenthos occurs in siliciclastic deposits of all Earth ages, from the early Archean to today. Studies in modern settings show how microbenthos responds to sediment dynamics by baffling and trapping, binding, biostabilization, and growth. Results of this microbial-sediment interaction are microbially induced sedimentary structures (MISS). Successful prospection for rich MISS occurrences in the terrestrial lithological record requires unraveling genesis and taphonomy of MISS, both of which are defined only by a narrow range of specific conditions. These conditions have to coincide with high detectability which is a function of outcrop quality, bedding character, and rock type. …


Characterizing El Niño-Southern Oscillation Effects On The Blue Nile Yield And The Nile River Basin Precipitation Using Empirical Mode Decomposition, Justin A. Le, Hesham El-Askary, Mohamed Allali, Eman Sayed, Hani Sweliem, Thomas C. Piechota, Daniele C. Struppa Nov 2020

Characterizing El Niño-Southern Oscillation Effects On The Blue Nile Yield And The Nile River Basin Precipitation Using Empirical Mode Decomposition, Justin A. Le, Hesham El-Askary, Mohamed Allali, Eman Sayed, Hani Sweliem, Thomas C. Piechota, Daniele C. Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

Using new mathematical and data-driven techniques, we propose new indices to measure and predict the strength of different El Niño events and how they affect regions like the Nile River Basin (NRB). Empirical Mode Decomposition (EMD), when applied to Southern Oscillation Index (SOI), yields three Intrinsic Mode Functions (IMF) tracking recognizable and physically significant non-stationary processes. The aim is to characterize underlying signals driving ENSO as reflected in SOI, and show that those signals also meaningfully affect other physical processes with scientific and predictive utility. In the end, signals are identified which have a strong statistical relationship with various physical …


Principles Of Organizing Earthquake Forecasting Based On Multiparameter Sensor-Web Monitoring Data, Sergey Pulinets, Dimitar Ouzounov, Dmitry Davidenko, Pavel Budnikov Oct 2020

Principles Of Organizing Earthquake Forecasting Based On Multiparameter Sensor-Web Monitoring Data, Sergey Pulinets, Dimitar Ouzounov, Dmitry Davidenko, Pavel Budnikov

Mathematics, Physics, and Computer Science Faculty Articles and Research

The paper describes an approach that allows, basing on the data of multiparameter monitoring of atmospheric and ionospheric parameters and using ground-based and satellite measurements, to select from the data stream a time interval indicating the beginning of the final stage of earthquake preparation, and finally using intelligent data processing to carry out a short-term forecast for a time interval of 2 weeks to 1 day before the main shock. Based on the physical model of the lithosphere-atmospheric-ionospheric coupling, the precursors are selected, the ensemble of which is observed only during the precursory periods, and their identification is based on …


The Source Detection Of 28 September 2018 Sulawesi Tsunami By Using Ionospheric Gnss Total Electron Content Disturbance, Jann-Yenq Liu, Chi-Yen Lin, Yuh-Ing Chen, Tso-Ren Wu, Meng-Ju Chung, Tien-Chi Liu, Yu-Lin Tsai, Loren C. Chang, Chi-Kuang Chao, Dimitar Ouzounov, Katsumi Hattori Aug 2020

The Source Detection Of 28 September 2018 Sulawesi Tsunami By Using Ionospheric Gnss Total Electron Content Disturbance, Jann-Yenq Liu, Chi-Yen Lin, Yuh-Ing Chen, Tso-Ren Wu, Meng-Ju Chung, Tien-Chi Liu, Yu-Lin Tsai, Loren C. Chang, Chi-Kuang Chao, Dimitar Ouzounov, Katsumi Hattori

Mathematics, Physics, and Computer Science Faculty Articles and Research

The 28 September 2018 magnitude Mw7.8 Palu, Indonesia earthquake (0.178° S, 119.840° E, depth 13 km) occurred at 10:02 UTC. The major earthquake triggered catastrophic liquefaction, landslides, and a near-field tsunami. The ionospheric total electron content (TEC) derived from records of 5 ground-based global navigation satellite system (GNSS) receivers is employed to detect tsunami traveling ionospheric disturbances (TTIDs). In total, 15 TTIDs have been detected. The ray-tracing and beamforming techniques are then used to find the TTID source location. The bootstrap method is applied in order to further explore the possible location of the tsunami source based on results of …


Statement Of World Aquatic Scientific Societies On The Need To Take Urgent Action Against Human-Caused Climate Change, Based On Scientific Evidence [Dear Colleague Letter], Scott A. Bonar, Brian R. Murphy, Leanne H. Roulson, Jesse T. Trushenski, Douglas J. Austen, Michael Edward Douglas Jul 2020

Statement Of World Aquatic Scientific Societies On The Need To Take Urgent Action Against Human-Caused Climate Change, Based On Scientific Evidence [Dear Colleague Letter], Scott A. Bonar, Brian R. Murphy, Leanne H. Roulson, Jesse T. Trushenski, Douglas J. Austen, Michael Edward Douglas

United States Fish and Wildlife Service: Publications

Dear Colleague Letter from the American Fisheries Society to fellow scientific societies, July 25, 2020, about the urgent need for responsive collective action to mitigate impending radical climate change. Includes the Statement of World Aquatic Scientific Societies on the Need to Take Urgent Action Against Human-Caused Climate Change, Based on Scientific Evidence, emphasizing the importance of aquatic ecosystems. Includes extensive citations and notes.

"Water is the most important natural resource on Earth as it is vital for life. Aquatic ecosystems, freshwater or marine, provide multiple benefits to human society, such as provisioning of oxygen, food, drinking water, genetic resources; regulation …


A Process-Based Approach To Evaluating The Role Of Organic Ligands In Trace Metal Cycling In The Marine Environment, Travis Mellett Jul 2020

A Process-Based Approach To Evaluating The Role Of Organic Ligands In Trace Metal Cycling In The Marine Environment, Travis Mellett

USF Tampa Graduate Theses and Dissertations

In addition to control by major nutrient elements (nitrogen, phosphorous, and silicon) growth and community composition of marine phytoplankton is also regulated by trace element nutrients (iron, copper, manganese, zinc, cobalt, nickel, and cadmium). Of these, iron is the most influential in the modern ocean, regulating phytoplankton growth and carbon export in high-nutrient low-chlorophyll regimes and exerting an important control on the marine nitrogen cycle through its role in di-nitrogen fixation. The distributions of these metals has the capacity to control primary production and phytoplankton community composition through differences in cellular quotas or metal sensitivities amongst species. The relationship between …


Investigating The Isotope Signatures Of Dissolved Iron In The Southern Atlantic Ocean, Brent A. Summers Jun 2020

Investigating The Isotope Signatures Of Dissolved Iron In The Southern Atlantic Ocean, Brent A. Summers

USF Tampa Graduate Theses and Dissertations

Iron (Fe), used as a cofactor in nitrogen fixation and photosynthesis by oceanic microorganisms, has extremely low dissolved concentrations in the surface ocean, leading to widespread limitation of phytoplankton growth. Dissolved Fe isotope ratios (δ56Fe) have been shown to be useful in helping to quantify the sources and cycling of Fe in the oceans if Fe source signatures and fractionation processes are well understood. Here, this thesis presents data from GEOTRACES section GA10W, and investigate the isotopic signature of sediment-derived dissolved Fe from the South Atlantic margins. My results show that there are both shallow (δ56Fe of -0.2‰) and deep …


Long-Term Ndvi And Recent Vegetation Cover Profiles Of Major Offshore Island Nesting Sites Of Sea Turtles In Saudi Waters Of The Northern Arabian Gulf, Rommel H. Maneja, Jeffrey D. Miller, Wenzhao Li, Hesham El-Askary, Ace Vincent B. Flandez, Joshua J. Dagoy, Joselito Francis A. Alcaria, Abdullajid U. Basali, Khaled A. Al-Abdulkader, Ronald A. Loughland, Mohamed A. Qurban Jun 2020

Long-Term Ndvi And Recent Vegetation Cover Profiles Of Major Offshore Island Nesting Sites Of Sea Turtles In Saudi Waters Of The Northern Arabian Gulf, Rommel H. Maneja, Jeffrey D. Miller, Wenzhao Li, Hesham El-Askary, Ace Vincent B. Flandez, Joshua J. Dagoy, Joselito Francis A. Alcaria, Abdullajid U. Basali, Khaled A. Al-Abdulkader, Ronald A. Loughland, Mohamed A. Qurban

Mathematics, Physics, and Computer Science Faculty Articles and Research

Vegetation is an important ecological component of offshore islands in the Arabian Gulf (AG), which maintains long-term resilience of these islands. This is achieved by influencing sediment retention and moisture acquisition via condensation during periods of high humidity and by providing a variety of microhabitats for island fauna. The resilience of offshore islands’ ecosystems in the Saudi waters is important because they host the largest number of nesting hawksbill and green turtles in the AG. This study defines the characteristics and the long-term trends in vegetation cover of the offshore islands used by sea turtles as nesting grounds in the …


Seasonal Transport Of Dissolved Inorganic Carbon And Total Alkalinity Across The Louisiana Shelf, Michelle M. Anderson Jun 2020

Seasonal Transport Of Dissolved Inorganic Carbon And Total Alkalinity Across The Louisiana Shelf, Michelle M. Anderson

LSU Master's Theses

Rivers and wetlands are a major source of terrestrial derived carbon for coastal ocean margins. Unfortunately, Louisiana’s wetlands are threatened by ongoing high rates of erosion, deterioration, and unprecedented rates of river water discharge that changes seasonally, leading to a net loss of terrestrial carbon into the northern Gulf of Mexico (nGOM). There exists a current lack of understanding about the distribution of dissolved inorganic carbon (DIC) and total alkalinity (TAlk) within the shallowest regions of the Louisiana shelf. Even less is known about how the transport of DIC alters seasonally with changes in river outflow and shelf currents. Quantifying …


Reconstructing Deep-Ocean Circulation During Cenozoic Climate Transitions From The Marine Sediment Record, Brian Romans Apr 2020

Reconstructing Deep-Ocean Circulation During Cenozoic Climate Transitions From The Marine Sediment Record, Brian Romans

Sustainability Seminar Series

Ocean circulation plays a critical role in the Earth’s climate system through the storage and transfer of heat and carbon dioxide. The North Atlantic and Southern Ocean are of particular interest because these are regions where deep-water components of global circulation develop. Dr. Romans uses the deep-sea sedimentary record to reconstruct past ocean circulation and its relationship to past climatic and tectonic conditions. He integrates information from a broad range of spatial and temporal scales, from seismic-reflection data that reveals regional sedimentation patterns to high resolution records based on quantitative grain-size analysis from cores. Dr. Romans will present research from …


The Role Of Island-Marsh Couplings In The Long-Term Sustainability Barrier Islands In The Face Of Accelerated Sea-Level Rise, Christopher Hein Mar 2020

The Role Of Island-Marsh Couplings In The Long-Term Sustainability Barrier Islands In The Face Of Accelerated Sea-Level Rise, Christopher Hein

Sustainability Seminar Series

Barrier islands are one of the most ubiquitous features of the coast . . . at least here along the US East Coast, which accounts for >10% of the world’s barrier islands. Little more than large, partially vegetated, subaerial sand bars, barrier island provide for recreation, ecosystem services, and protection of mainland communities from storm impacts. They are also some of the most dynamic features on earth, constantly changing in the face of waves, tides, wind, and currents. With examples from northern Massachusetts and the Virginia Eastern Shore, this talk will focus on the long-term sustainability of barrier islands, and …


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 Mar 2020

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 …


Development Of A Sensor Suite For Atmospheric Boundary Layer Measurement With A Small Multirotor Unmanned Aerial System, Kevin A. Adkins, Christopher J. Swinford, Peter D. Wambolt, Gordon Bease Jan 2020

Development Of A Sensor Suite For Atmospheric Boundary Layer Measurement With A Small Multirotor Unmanned Aerial System, Kevin A. Adkins, Christopher J. Swinford, Peter D. Wambolt, Gordon Bease

International Journal of Aviation, Aeronautics, and Aerospace

Small unmanned aerial systems (sUAS) are increasingly being used to conduct atmospheric research. Because of the dynamic nature and inhomogeneity of the atmospheric boundary layer (ABL), the ability of instrumented sUAS to make on-demand 3-dimensional high-resolution spatial measurements of atmospheric parameters makes them particularly suited to ABL investigations. Both fixed-wing and multirotor sUAS have been used for ABL investigations. Most investigations to date have included in-situ measurement of thermodynamic quantities such as temperature, pressure and humidity. When wind has been measured, a variety of strategies have been used. Two of the most popular techniques have been deducing wind from inertial …


Reconstructing Geographic And Trophic Histories Of Fish Using Bulk And Compound-Specific Stable Isotopes From Eye Lenses, Amy A. Wallace Nov 2019

Reconstructing Geographic And Trophic Histories Of Fish Using Bulk And Compound-Specific Stable Isotopes From Eye Lenses, Amy A. Wallace

USF Tampa Graduate Theses and Dissertations

The present research examined the viability and utility of eye lenses as a source of lifetime stable-isotope records in fish. It is presented in three sections. The first section compared bulk isotopic variation (bulk analysis) within fish eye-lenses at two temporal resolutions and compared patterns obtained from left and right eyes. The first temporal resolution was lower in an attempt to expose broad-scale isotopic changes during life while reducing effort and cost. This approach did reveal lifetime patterns, but tended to miss certain life events, particularly during early life. The second resolution was higher and provided detail that was missed …


A Collection Of On-Ice Arctic Measurements 1879-2013, Ryan Avila Sep 2019

A Collection Of On-Ice Arctic Measurements 1879-2013, Ryan Avila

STAR Program Research Presentations

Ice thickness measurements have been taken in the arctic through a variety of means for a long time in order to better understand the long-term changes to sea ice. This project is focused on measurements made directly on the ice by using an auger or electromagnetic sounding which have both been shown to be highly accurate compared to other observational methods. Our first goal is to create and update an archive of sea ice data that collects smaller separated data sets in one easy to access location for other researchers to use. Our second goal is to use this data …


Response And Recovery Of Horn And Petit Bois Islands, Mississippi, Usa To Tropical Cyclone Impacts: 2004 – 2016, Shara Gremillion Aug 2019

Response And Recovery Of Horn And Petit Bois Islands, Mississippi, Usa To Tropical Cyclone Impacts: 2004 – 2016, Shara Gremillion

Master's Theses

Horn and Petit Bois islands are two of five Mississippi (MS) barrier islands that provide physical protection from tropical cyclones threatening the MS Gulf Coast, in addition to critical habitat for the northern Gulf of Mexico (GOM). In September 2004, Hurricane Ivan removed a large volume of sediment from the eastern ends of Horn and Petit Bois islands with its 1-2 m storm surge and ~194 kph wind speeds. Then, in August 2005 Hurricane Katrina severely impacted the two islands again with its 3.5-5.5 m storm surge on Horn and Petit Bois islands, and up to 204 kph wind speeds …


Tropospheric And Ionospheric Anomalies Induced By Volcanic And Saharan Dust Events As Part Of Geosphere Interaction Phenomena, Valerio Tramutoli, Francesco Marchese, Alfredo Falconieri, Carolina Filizzola, Nicola Genzano, Katsumi Hattori, Mariano Lisi, Jann-Yenq Liu, Dimitar Ouzounov, Michel Parrot, Nicola Pergola, Sergey Pulinets Apr 2019

Tropospheric And Ionospheric Anomalies Induced By Volcanic And Saharan Dust Events As Part Of Geosphere Interaction Phenomena, Valerio Tramutoli, Francesco Marchese, Alfredo Falconieri, Carolina Filizzola, Nicola Genzano, Katsumi Hattori, Mariano Lisi, Jann-Yenq Liu, Dimitar Ouzounov, Michel Parrot, Nicola Pergola, Sergey Pulinets

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this work, we assessed the possible relation of ionospheric perturbations observed by Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions (DEMETER), Global Positioning System total electron content (GPS TEC), National Oceanic and Atmospheric Administration (NOAA)-derived outgoing longwave-Earth radiation (OLR), and atmospheric chemical potential (ACP) measurements, with volcanic and Saharan dust events identified by ground and satellite-based medium infrared/thermal infrared (MIR/TIR) observations. The results indicated that the Mt. Etna (Italy) volcanic activity of 2006 was probably responsible for the ionospheric perturbations revealed by DEMETER on 4 November and 6 December and by GPS TEC observations on 4 November and 12 …


Seasonal Origins Of Soil Water Used By Trees, Scott T. Allen, James W. Kirchner, Sabine Braun, Rolf T. W. Siegwolf, Gregory R. Goldsmith Mar 2019

Seasonal Origins Of Soil Water Used By Trees, Scott T. Allen, James W. Kirchner, Sabine Braun, Rolf T. W. Siegwolf, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Rain recharges soil water storages and either percolates downward into aquifers and streams or is returned to the atmosphere through evapotranspiration. Although it is commonly assumed that summer rainfall recharges plant-available water during the growing season, the seasonal origins of water used by plants have not been systematically explored. We characterize the seasonal origins of waters in soils and trees by comparing their midsummer isotopic signatures (δ2H) to seasonal isotopic cycles in precipitation, using a new seasonal origin index. Across 182 Swiss forest sites, xylem water isotopic signatures show that summer rain was not the predominant water source …


Coupling Between Land–Ocean–Atmosphere And Pronounced Changes In Atmospheric/Meteorological Parameters Associated With The Hudhud Cyclone Of October 2014, Akshansa Chauhan, Rajesh Kumar, Ramesh P. Singh Dec 2018

Coupling Between Land–Ocean–Atmosphere And Pronounced Changes In Atmospheric/Meteorological Parameters Associated With The Hudhud Cyclone Of October 2014, Akshansa Chauhan, Rajesh Kumar, Ramesh P. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

India is vulnerable to all kinds of natural hazards associated with land, ocean, biosphere, atmosphere, and snow/glaciers. These natural hazards impact large areas and the population living in the affected regions. India is surrounded by ocean on three sides and is vulnerable to cyclonic activities. Every year cyclones hit the east and west coasts of India, affecting the population living along the coasts and infrastructure and inland areas. The extent of the affected inland areas depends on the intensity of the cyclone. On 12 October 2014, a strong cyclone “Hudhud” hit the east coast of India that caused a high …


Spatial And Temporal Distributions Of Pelagic Sargassum In The Intra-Americas Sea And Atlantic Ocean, Mengqiu Wang Jul 2018

Spatial And Temporal Distributions Of Pelagic Sargassum In The Intra-Americas Sea And Atlantic Ocean, Mengqiu Wang

USF Tampa Graduate Theses and Dissertations

Pelagic Sargassum is one type of marine macroalgae that is known to be abundant in the Gulf of Mexico and Sargasso Sea. It is also known to serve as a critical habitat for many marine animals. In the past few years, large amounts of Sargassum have been reported in the Tropical Atlantic and Caribbean Sea (CS), causing significant environmental and economic problems. The goal of this study is to improve the understanding of Sargassum distributions, quantity, transport pathways, and bloom mechanisms in the CS and Tropic Atlantic through combining a variety of techniques including satellite remote sensing, field and laboratory …


Estimating Live Fuel Moisture In Southern California Using Remote Sensing Vegetation Water Content Proxies, Shenyue Jia, Seung Hee Kim, Son V. Nghiem, Wonhee Cho, Menas Kafatos Jul 2018

Estimating Live Fuel Moisture In Southern California Using Remote Sensing Vegetation Water Content Proxies, Shenyue Jia, Seung Hee Kim, Son V. Nghiem, Wonhee Cho, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Wildfires are a major ecological disturbance in Southern California and often lead to great destruction along the Wildland-Urban Interface. Live fuel moisture has been used as an important indicator of wildfire risk in measurements of vegetation water content. However, the limited field measurements of live fuel moisture in both time and space have affected the accuracy of wildfire risk estimations. Traditional estimation of live fuel moisture using remote sensing data was based on vegetation indices, indirect proxies of vegetation water content and subject to influence from weather conditions. In this study, we investigated the feasibility of estimating live fuel moisture …


A Novel Multiproxy Approach To Reconstructing Sea Surface Temperature In The Southwestern Gulf Of Mexico, Marissa Anne Vara May 2018

A Novel Multiproxy Approach To Reconstructing Sea Surface Temperature In The Southwestern Gulf Of Mexico, Marissa Anne Vara

LSU Master's Theses

Coral Sr/Ca is a widely-used proxy for sea surface temperature (SST); however, discrepancies in the coral Sr/Ca-SST relationship among colonies of the same species makes uncertainty in absolute temperature reconstructions larger than the climate signal yet climate variability studies are possible. Furthermore, the riverine input of terrestrial carbonate weathering products to the coastal waters can disrupt the coral Sr/Ca-SST signal by changing local seawater chemistry. This study evaluates the fidelity and reproducibly of coral SST proxies (Sr/Ca, Li/Ca, Mg/Li, Sr-U, Mg/Ca, and U/Ca) and a riverine-upwelling proxy (Ba/Ca) in four Orbicella faveolata colonies in two reefs offshore from Veracruz, Mexico …


Predicting Spatial Patterns In Precipitation Isotope (Δ2h And Δ18o) Seasonality Using Sinusoidal Isoscapes, Scott T. Allen, James W. Kirchner, Gregory R. Goldsmith May 2018

Predicting Spatial Patterns In Precipitation Isotope (Δ2h And Δ18o) Seasonality Using Sinusoidal Isoscapes, Scott T. Allen, James W. Kirchner, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Understanding how precipitation isotopes vary spatially and temporally is important for tracer applications. We tested how well month‐to‐month variations in precipitation δ18O and δ2H were captured by sinusoidal cycles, and how well spatial variations in these seasonal cycles could be predicted, across Switzerland. Sine functions representing seasonal cycles in precipitation isotopes explained between 47% and 94% of the variance in monthly δ18O and δ2H values at each monitoring site. A significant sinusoidal cycle was also observed in line‐conditioned excess. We interpolated the amplitudes, phases, and offsets of these sine functions across the landscape, using multiple linear …