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Articles 271 - 300 of 984

Full-Text Articles in Climate

Evaluation Of Remotely Sensed Precipitation Estimates From The Nasa Power Project For Drought Detection Over Jordan, Muhammad Rasool Al‑Kilani, Michel Rahbeh, Jawad Al‑Bakri, Tsegaye Tadesse, Cody Knutson Jan 2021

Evaluation Of Remotely Sensed Precipitation Estimates From The Nasa Power Project For Drought Detection Over Jordan, Muhammad Rasool Al‑Kilani, Michel Rahbeh, Jawad Al‑Bakri, Tsegaye Tadesse, Cody Knutson

National Drought Mitigation Center: Faculty Publications

Droughts can cause devastating impacts on water and land resources and therefore monitoring these events forms an integral part of planning. The most common approach for detecting drought events and assessing their intensity is use of the Standardized Precipitation Index (SPI), which requires abundant precipitation records at good spatial distribution. This may restrict SPI usage in many regions around the world, particularly in areas with limited numbers of ground meteorological stations. Therefore, the use of remotely sensed derived data of precipitation can contribute to drought monitoring. In this study, remotely sensed precipitation estimates from the POWER/Agroclimatology archive of NASA and …

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A Model-Based Exploratory Study Of Sulfur Dioxide Dispersions From Concentrated Animal Feeding Operations In The Southeastern United States, Jesse Winchester, Rezaul Mahmood, William Rodgers, Philip J. Silva, Nanh Lovanh, Joshua D. Durkee, John Loughrin Jan 2021

A Model-Based Exploratory Study Of Sulfur Dioxide Dispersions From Concentrated Animal Feeding Operations In The Southeastern United States, Jesse Winchester, Rezaul Mahmood, William Rodgers, Philip J. Silva, Nanh Lovanh, Joshua D. Durkee, John Loughrin

High Plains Regional Climate Center: Staff Publications

In the Southeastern U. S. there are Concentrated Animal Feeding Operations (CAFOs) that emit a variety of gases, including SO2. Sulfur is emitted as reduced sulfur compounds and can react in the atmosphere to produce SO2. It is expected that the concentra­tion and spread of SO2 emissions from these sources would differ between wet and dry periods. In this research, SO2 emissions from locations representing CAFOs and its dispersion over the south­eastern U.S. were simulated through sensitivity experiments using the Weather Research and Forecasting-Chemistry (WRF- Chem) model. Simulations were performed for dry periods and …

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Droughtscape, Winter 2021, National Drought Mitigation Center Jan 2021

Droughtscape, Winter 2021, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

DroughtScape, Winter 2021

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Constraining 20th‐Century Sea‐Level Rise In The South Atlantic Ocean, Thomas Frederikse, Surendra Adhikari, Tim J. Daley, Sönke Dangendorf, Roland Gehrels, Felix Landerer, Marta Marcos, Thomas L. Newton, Graham Rush, Aimée B.A. Slangen, Guy Wöppelmann Jan 2021

Constraining 20th‐Century Sea‐Level Rise In The South Atlantic Ocean, Thomas Frederikse, Surendra Adhikari, Tim J. Daley, Sönke Dangendorf, Roland Gehrels, Felix Landerer, Marta Marcos, Thomas L. Newton, Graham Rush, Aimée B.A. Slangen, Guy Wöppelmann

OES Faculty Publications

Sea level in the South Atlantic Ocean has only been measured at a small number of tide-gauge locations, which causes considerable uncertainty in 20th-century sea-level trend estimates in this basin. To obtain a better-constrained sea-level trend in the South Atlantic Ocean, this study aims to answer two questions. The first question is: can we combine new observations, vertical land motion estimates, and information on spatial sampling biases to obtain a likely range of 20th-century sea-level rise in the South Atlantic? We combine existing observations with recovered observations from Dakar and a high-resolution sea-level reconstruction based on salt-marsh sediments from the …

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Effects Of Tidal Flooding On Estuarine Biogeochemistry: Quantifying Flood-Driven Nitrogen Inputs In An Urban, Lower Chesapeake Bay Sub-Tributary, Alfonso Macías-Tapia, Margaret R. Mulholland, Corday R. Selden, J. Derek Loftis, Peter W. Bernhardt Jan 2021

Effects Of Tidal Flooding On Estuarine Biogeochemistry: Quantifying Flood-Driven Nitrogen Inputs In An Urban, Lower Chesapeake Bay Sub-Tributary, Alfonso Macías-Tapia, Margaret R. Mulholland, Corday R. Selden, J. Derek Loftis, Peter W. Bernhardt

OES Faculty Publications

Sea level rise has increased the frequency of tidal flooding even without accompanying precipitation in many coastal areas worldwide. As the tide rises, inundates the landscape, and then recedes, it can transport organic and inorganic matter between terrestrial systems and adjacent aquatic environments. However, the chemical and biological effects of tidal flooding on urban estuarine systems remain poorly constrained. Here, we provide the first extensive quantification of floodwater nutrient concentrations during a tidal flooding event and estimate the nitrogen (N) loading to the Lafayette River, an urban tidal sub-tributary of the lower Chesapeake Bay (USA). To enable the scale of …

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Seasonal Dispersal Of Fjord Meltwaters As An Important Source Of Iron And Manganese To Coastal Antarctic Phytoplankton, Kiefer O. Forsch, Lisa Hahn-Woernle, Robert M. Sherrell, Vincent J. Roccanova, Kaixuan Bu, David Burdige, Maria Vernet, Katherine A. Barbeau Jan 2021

Seasonal Dispersal Of Fjord Meltwaters As An Important Source Of Iron And Manganese To Coastal Antarctic Phytoplankton, Kiefer O. Forsch, Lisa Hahn-Woernle, Robert M. Sherrell, Vincent J. Roccanova, Kaixuan Bu, David Burdige, Maria Vernet, Katherine A. Barbeau

OES Faculty Publications

Glacial meltwater from the western Antarctic Ice Sheet is hypothesized to be an important source of cryospheric iron, fertilizing the Southern Ocean, yet its trace-metal composition and factors that control its dispersal remain poorly constrained. Here we characterize meltwater iron sources in a heavily glaciated western Antarctic Peninsula (WAP) fjord. Using dissolved and particulate ratios of manganese to iron in meltwaters, porewaters, and seawater, we show that surface glacial melt and subglacial plumes contribute to the seasonal cycle of iron and manganese within a fjord still relatively unaffected by climate-change-induced glacial retreat. Organic ligands derived from the phytoplankton bloom and …

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Anticipating And Adapting To The Future Impacts Of Climate Change On The Health, Security And Welfare Of Low Elevation Coastal Zone (Lecz) Communities In Southeastern Usa, Thomas Allen, Joshua Behr, Anamaria Bukvic, Ryan S.D. Calder, Kiki Caruson, Charles Connor, Christopher D'Elia, David Dismukes, Robin Ersing, Rima Franklin, Jesse Goldstein, Jonathon Goodall, Scott Hemmerling, Jennifer Irish, Steven Lazarus, Derek Loftis, Mark Luther, Leigh Mccallister, Karen Mcglathery, Molly Mitchell, William Moore, Charles Reid Nichols, Karinna Nunez, Matthew Reidenbach, Julie Shortridge, Robert Weisberg, Robert Weiss, Lynn Donelson Wright, Meng Xia, Kehui Xu, Donald Young, Gary Zarillo, Julie C. Zinnert Jan 2021

Anticipating And Adapting To The Future Impacts Of Climate Change On The Health, Security And Welfare Of Low Elevation Coastal Zone (Lecz) Communities In Southeastern Usa, Thomas Allen, Joshua Behr, Anamaria Bukvic, Ryan S.D. Calder, Kiki Caruson, Charles Connor, Christopher D'Elia, David Dismukes, Robin Ersing, Rima Franklin, Jesse Goldstein, Jonathon Goodall, Scott Hemmerling, Jennifer Irish, Steven Lazarus, Derek Loftis, Mark Luther, Leigh Mccallister, Karen Mcglathery, Molly Mitchell, William Moore, Charles Reid Nichols, Karinna Nunez, Matthew Reidenbach, Julie Shortridge, Robert Weisberg, Robert Weiss, Lynn Donelson Wright, Meng Xia, Kehui Xu, Donald Young, Gary Zarillo, Julie C. Zinnert

Political Science & Geography Faculty Publications

Low elevation coastal zones (LECZ) are extensive throughout the southeastern United States. LECZ communities are threatened by inundation from sea level rise, storm surge, wetland degradation, land subsidence, and hydrological flooding. Communication among scientists, stakeholders, policy makers and minority and poor residents must improve. We must predict processes spanning the ecological, physical, social, and health sciences. Communities need to address linkages of (1) human and socioeconomic vulnerabilities; (2) public health and safety; (3) economic concerns; (4) land loss; (5) wetland threats; and (6) coastal inundation. Essential capabilities must include a network to assemble and distribute data and model code to …

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Predicting The Impacts Of Climate Change On The Great Lakes Water Levels Using A Fully Coupled 3d Regional Modeling System, Miraj Kayastha Jan 2021

Predicting The Impacts Of Climate Change On The Great Lakes Water Levels Using A Fully Coupled 3d Regional Modeling System, Miraj Kayastha

Dissertations, Master's Theses and Master's Reports

The Great Lakes of North America are the largest surface freshwater system in the world and many ecosystems, industries, and coastal processes are sensitive to the changes in their water levels. The recent changes in the Great Lakes climate and water levels have particularly highlighted the importance of water level prediction. The water levels of the Great Lakes are primarily governed by the net basin supplies (NBS) of each lake which are the sum of over-lake precipitation and basin runoff minus lake evaporation. Recent studies have utilized Regional Climate Models (RCMs) with a fully coupled one-dimensional (1D) lake model to …

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Experiential Learning In Soil Science: Evaluating Soil Quality In South Wollo, Ethiopia, Melissa Allen, Martha Mamo, Shimelis Beyene, Teshome Regassa, Gandura O. Abagandura, Solomon Abreha, Anthony James Mucia, Tsegaye Tadesse Jan 2021

Experiential Learning In Soil Science: Evaluating Soil Quality In South Wollo, Ethiopia, Melissa Allen, Martha Mamo, Shimelis Beyene, Teshome Regassa, Gandura O. Abagandura, Solomon Abreha, Anthony James Mucia, Tsegaye Tadesse

National Drought Mitigation Center: Faculty Publications

This study abroad program provided an opportunity to enhance the international experience and research skills of University of Nebraska-Lincoln (UNL) students within a multidisciplinary team’s research-education goal on improving food security in Ethiopia. The experiential study component of the project included preparatory sessions during the Fall 2015 Semester at the UNL followed by a four- to five-week fieldwork experience in Ethiopia. Teams from the UNL and an Ethiopian university participated in survey data collection and field soil evaluations from farms in the Gerado area of South Wollo, Ethiopia. Having students interact with farmers increased student self-confidence and enhanced their leadership …

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The Rise And Fall Of Wiñaymarka: Rethinking Cultural And Environmental Interactions In The Southern Basin Of Lake Titicaca, Maria C. Bruno, José M. Capriles, Christine A. Hastorf, Sherilyn C. Fritz, D. Marie Weide, Alejandra I. Domic, Paul A. Baker Jan 2021

The Rise And Fall Of Wiñaymarka: Rethinking Cultural And Environmental Interactions In The Southern Basin Of Lake Titicaca, Maria C. Bruno, José M. Capriles, Christine A. Hastorf, Sherilyn C. Fritz, D. Marie Weide, Alejandra I. Domic, Paul A. Baker

Department of Earth and Atmospheric Sciences: Faculty Publications

Investigations of how past human societies managed during times of major climate change can inform our understanding of potential human responses to ongoing environmental change. In this study, we evaluate the impact of environmental variation on human communities over the last four millennia in the southern Lake Titicaca basin of the Andes, known as Lake Wiñaymarka. Refined paleoenvironmental reconstructions from new diatom-based reconstructions of lake level together with archaeological evidence of animal and plant resource use from sites on the Taraco Peninsula, Bolivia, reveal frequent climate and lake-level changes within major cultural phases. We posit that climate fluctuations alone do …

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Inference Of Surface Velocities From Oblique Time Lapse Photos And Terrestrial Based Lidar At The Helheim Glacier, Franklyn T. Dunbar Ii Jan 2021

Inference Of Surface Velocities From Oblique Time Lapse Photos And Terrestrial Based Lidar At The Helheim Glacier, Franklyn T. Dunbar Ii

Graduate Student Theses, Dissertations, & Professional Papers

Using time dependent observations derived from terrestrial LiDAR and oblique
time-lapse imagery, we demonstrate that a Bayesian approach to glacial motion es-
timation provides a concise way to incorporate multiple data products into a single
motion estimation procedure effectively producing surface velocity estimates with
an associated uncertainty. This approach brings both improved computational effi-
ciency, and greater scalability across observational time-frames when compared to
existing methods. To gauge efficacy, we apply these methods to a set of observa-
tions from the Helheim Glacier, a critical actor in contemporary mass loss trends
observed in the Greenland Ice Sheet. We find that …

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Recent Flooding Events On The Chagrin And Cuyahoga Rivers, Ohio, Kayley Martin Jan 2021

Recent Flooding Events On The Chagrin And Cuyahoga Rivers, Ohio, Kayley Martin

Williams Honors College, Honors Research Projects

From the 1910s through the 1980s, the number of intense daily precipitation events in the United States remained constant, however, since the 1980s there has been an increasing trend in intense single-day precipitation events (U.S Environmental Protection Agency, 2016). One outcome of intense precipitation events is river flooding, particularly in the upper Midwest region where floods have increased in magnitude and frequency (U.S Environmental Protection Agency, 2016). In this thesis project, recent flooding history on the Chagrin and Cuyahoga Rivers in Ohio was studied to expand on previous research that observed an abrupt increase in high magnitude flood events on …

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Temperature Variance Portends And Indicates The Extent Of Abrupt Climate Shifts, Christine Ramadhin, Chuixiang Yi, George Hendrey Jan 2021

Temperature Variance Portends And Indicates The Extent Of Abrupt Climate Shifts, Christine Ramadhin, Chuixiang Yi, George Hendrey

Publications and Research

Here, we show a discernable increase in temperature variance before a glacial termination by both the Ansari-Bradley test and the moving variance methods plus introduce the idea that there is a correlation between the peak variance and peak temperature increase. The behavior of temperature variance shows potential as a useful tool in analyzing time series data of Earth systems to assess the risk and extent of an upcoming abrupt climate transition.

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Wave Climate Associated With Changing Water Level And Ice Cover In Lake Michigan, Chenfu Huang, Longhuan Zhu, Gangfeng Ma, Guy A. Meadows, Pengfei Xue Jan 2021

Wave Climate Associated With Changing Water Level And Ice Cover In Lake Michigan, Chenfu Huang, Longhuan Zhu, Gangfeng Ma, Guy A. Meadows, Pengfei Xue

Civil & Environmental Engineering Faculty Publications

Detailed knowledge of wave climate change is essential for understanding coastal geomorphological processes, ecosystem resilience, the design of offshore and coastal engineering structures and aquaculture systems. In Lake Michigan, the in-situ wave observations suitable for long-term analysis are limited to two offshore MetOcean buoys. Since this distribution is inadequate to fully represent spatial patterns of wave climate across the lake, a series of high-resolution SWAN model simulations were performed for the analysis of long-term wave climate change for the entirety of Lake Michigan from 1979 to 2020. Model results were validated against observations from two offshore buoys and 16 coastal …

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Characterizing Seagrass Effects On Hydrodynamics Of Waves And Currents Through Field Measurements And Computational Modelling, Ramin Familkhalili, Navid Tahvildari Jan 2021

Characterizing Seagrass Effects On Hydrodynamics Of Waves And Currents Through Field Measurements And Computational Modelling, Ramin Familkhalili, Navid Tahvildari

Civil & Environmental Engineering Faculty Publications

Low-lying coastal and estuarine areas are among the most populated regions globally, have high economic significance, and are increasingly threatened by climate change, sea level rise, nuisance flooding, and extreme storms. Nature-based coastal protections are sustainable and sea-level resilient alternatives compared to traditional solutions such as dikes and seawalls. Submerged aquatic vegetation (SAV) or seagrasses can provide coastal flood and erosion protection by attenuating storm wave and current energy and stabilizing seabed sediments. However, more research is needed to understand the interactions between flow, SAVs, and sediments. These dynamic interactions affect flow at different scales and seagrass productivity. In this …

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Effects Of Hydrological And Climatic Variables On Cyanobacterial Blooms In Four Large Shallow Lakes Fed By The Yangtze River, Jian Huang, Qiujin Xu, Xixi Wang, Hao Ji, Edward J. Quigley, Mohamadali Sharbatmaleki, Simeng Li, Beidou Xi, Biao Sun, Caole Li Jan 2021

Effects Of Hydrological And Climatic Variables On Cyanobacterial Blooms In Four Large Shallow Lakes Fed By The Yangtze River, Jian Huang, Qiujin Xu, Xixi Wang, Hao Ji, Edward J. Quigley, Mohamadali Sharbatmaleki, Simeng Li, Beidou Xi, Biao Sun, Caole Li

Civil & Environmental Engineering Faculty Publications

Shallow lakes, one of the most widespread water bodies in the world, are easily shifted to a new trophic state due to external interferences. Shifting hydrologic conditions and climate change can cause cyanobacterial harmful algal blooms (CyanoHABs) in shallow lakes, which pose serious threats to ecological integrity and human health. This study analyzed the effects of hydrologic and meteorological variables on cyanobacterial blooms in Yangtze-connected lakes (Lake Dongting and Poyang) and isolated lakes (Lake Chao and Tai). The results show that (i) chlorophyll-a (Chl-a) concentration tends to decrease exponentially with increasing relative lake level fluctuations (RLLF) and precipitation, but to …

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Diatoms And Their Response To Tectonic Gateway Changes: Case Studies From Southern Hemisphere Sites, Jason James Coenen Jan 2021

Diatoms And Their Response To Tectonic Gateway Changes: Case Studies From Southern Hemisphere Sites, Jason James Coenen

Graduate Research Theses & Dissertations

This dissertation covers three major transitions in Earth's climate system throughout theCenozoic (the past 65 million years of Earth's history). The progressive breakup of the super continent Pangea and the ultimate change in ocean circulation (and redistribution of heat) as a result of tectonic events dating back to the Mesozoic, primed Earth's climate system for cooling and ultimately bipolar glaciation. Climate transitions in three distinct environments were studied using absolute diatom abundance, diatom assemblages, and geochemical tracers of diatoms (i.e., biogenic silica weight%). Two geographic regions are the focus of this dissertation work. Region one is the Ross Embayment of …

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Cascading Effects: Insights From The U.S. Long Term Ecological Research Network, Christie A. Bahlai, Clarisse Hart, Maria T. Kavanaugh, Jeffrey D. White, Roger W. Ruess, Todd J. Brinkman, Hugh W. Ducklow, David R. Foster, William R. Fraser, Hélène Genet, Peter M. Groffman, Stephen K. Hamilton, Jill F. Johnstone, Knut Kielland, Douglas A. Landis, Michelle C. Mack, Orlando Sarnelle, Jonathan R. Thompson Jan 2021

Cascading Effects: Insights From The U.S. Long Term Ecological Research Network, Christie A. Bahlai, Clarisse Hart, Maria T. Kavanaugh, Jeffrey D. White, Roger W. Ruess, Todd J. Brinkman, Hugh W. Ducklow, David R. Foster, William R. Fraser, Hélène Genet, Peter M. Groffman, Stephen K. Hamilton, Jill F. Johnstone, Knut Kielland, Douglas A. Landis, Michelle C. Mack, Orlando Sarnelle, Jonathan R. Thompson

Advanced Science Research Center

Ecosystems across the United States are changing in complex and unpredictable ways and analysis of these changes requires coordinated, long-term research. This paper is a product of a synthesis effort of the U.S. National Science Foundation funded Long-Term Ecological Research (LTER) network addressing the LTER core research area of “populations and communities.” This analysis revealed that each LTER site had at least one compelling “story” about what their site would look like in 50–100 yr. As the stories were prepared, themes emerged, and the stories were group into papers along five themes: state change, connectivity, resilience, time lags, and cascading …

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Evaluation Of A Low-Cost Uas And Phenocams For Measuring Grapevine Greenness, Timothy J. Hoheneder Jan 2021

Evaluation Of A Low-Cost Uas And Phenocams For Measuring Grapevine Greenness, Timothy J. Hoheneder

Graduate Theses, Dissertations, and Problem Reports (ETD)

Unpersoned aerial systems (UAS) could provide winegrowers with the potential to monitor vineyard productivity with ultra-high-resolution imagery and low operational costs. This ability could prove particularly valuable in the challenging cool-climate viticultural areas of Appalachia. Especially in this mountainous region of increasingly variable microclimates, there could be of great value from an ability to use UAS-measured greenness to monitor wine grape phenology and predict harvest quality and quantity. In this study, I assess how UAS-measured greenness relates to three complementary measures of field-based: leaf angle measurements, phenocam measured greenness, and leaf spectral measurements of greenness. After correlating these field-based measures …

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Modulation Of Late Pleistocene Enso Strength By The Tropical Pacific Thermocline, Gerald T. Rustic, Pratigya J. Polissar, Ana Christina Ravelo, Sarah M. White Dec 2020

Modulation Of Late Pleistocene Enso Strength By The Tropical Pacific Thermocline, Gerald T. Rustic, Pratigya J. Polissar, Ana Christina Ravelo, Sarah M. White

School of Earth & Environment Departmental Research

The El Niño Southern Oscillation (ENSO) is highly dependent on coupled atmosphere-ocean interactions and feedbacks, suggesting a tight relationship between ENSO strength and background climate conditions. However, the extent to which background climate state determines ENSO behavior remains in question. Here we present reconstructions of total variability and El Niño amplitude from individual foraminifera distributions at discrete time intervals over the past ~285,000 years across varying atmospheric CO2 levels, global ice volume and sea level, and orbital insolation forcing. Our results show a strong correlation between eastern tropical Pacific Ocean mixed-layer thickness and both El Niño amplitude and central Pacific …

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Influence Of Some Climatic Elements On Radon Concentration In Saeva Dupka Cave, Bulgaria, Peter Nojarov, Petar Stefanov, Karel Turek Dec 2020

Influence Of Some Climatic Elements On Radon Concentration In Saeva Dupka Cave, Bulgaria, Peter Nojarov, Petar Stefanov, Karel Turek

International Journal of Speleology

This study reveals the influence of some climatic elements on radon concentration in Saeva Dupka Cave, Bulgaria. The research is based mainly on statistical methods. Radon concentration in the cave is determined by two main mechanisms. The first one is through penetration of radon from soil and rocks around the cave (present all year round, but has leading role during the warm half of the year). The second one is through thermodynamic exchange of air between inside of the cave and outside atmosphere (cold half of the year). Climatic factors that affect radon concentration in the cave are temperatures (air, …

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Species Distribution Modeling For Arid Adapted Habitat Specialists In Zion National Park, Sam Driver, Daniel R. Unger, David L. Kulhavy, Chris M. Schalk Dec 2020

Species Distribution Modeling For Arid Adapted Habitat Specialists In Zion National Park, Sam Driver, Daniel R. Unger, David L. Kulhavy, Chris M. Schalk

Student Publications

The Arizona toad (Anaxyrus microscaphus) and Jones’ waxy dogbane (Cycladenia humilis var. jonesii) are habitat specialists with historical ranges in the desert southwest and specifically, Zion National Park (ZION). The machine learning method, MaxEnt, constructed species distribution models (SDMs) in ZION for the two study species at 30 m and 900 m spatial resolutions using climate, topographic, and remotely sensed data. Additionally, 900 m forecasting models were constructed to observe the shifts in suitable habitat for the years 2050 and 2070, based off two representative concentration pathway scenarios. Results indicate promising predictive power for both high …

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Response Of Deep Aquifers To Climate Variability, Karem Fathy Abdelgaber Abdelmohsen Dec 2020

Response Of Deep Aquifers To Climate Variability, Karem Fathy Abdelgaber Abdelmohsen

Dissertations

Our recent analysis of Temporal Gravity Recovery and Climate Experiment (GRACE) solutions over the largest aquifer system in Africa (the Nubian Sandstone Aquifer System: NSAS) revealed that while the response of deep aquifers to climatic variations remains a relatively slow process that takes thousands to tens of thousands of years, there is a much faster response in aquifers that are characterized by dense networks of faults, fractures and karst as is the case with the NSAS. This rapid groundwater flow, when it occurs, is detected as an increase in GRACETWS over areas downgradient and distant (hundreds of km) from …

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Building An Improved Drought Climatology Using Updated Drought Tools: A New Mexico Food-Energy-Water (Few) Systems Focus, Lindsay E. Johnson, Hatim M.E. Geli, Michael J. Hayes, Kelly Helm Smith Dec 2020

Building An Improved Drought Climatology Using Updated Drought Tools: A New Mexico Food-Energy-Water (Few) Systems Focus, Lindsay E. Johnson, Hatim M.E. Geli, Michael J. Hayes, Kelly Helm Smith

National Drought Mitigation Center: Faculty Publications

Drought is a familiar climatic phenomenon in the United States Southwest, with complex human-environment interactions that extend beyond just the physical drought events. Due to continued climate variability and change, droughts are expected to become more frequent and/or severe in the future. Decision-makers are charged with mitigating and adapting to these more extreme conditions and to do that they need to understand the specific impacts drought has on regional and local scales, and how these impacts compare to historical conditions. Tremendous progress in drought monitoring strategies has occurred over the past several decades, with more tools providing greater spatial and …

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Sodium-Calcium Ratios In The Planktic Foraminifera Trilobatus Sacculifer As A Proxy For Sea Surface Salinity, Colton Steele Watkins Dec 2020

Sodium-Calcium Ratios In The Planktic Foraminifera Trilobatus Sacculifer As A Proxy For Sea Surface Salinity, Colton Steele Watkins

OES Theses and Dissertations

Recent culture and field studies have found a significant positive correlation between seawater salinity and the incorporation of sodium into foraminiferal calcite, suggesting a potential new proxy for reconstructing past changes in sea surface salinity (SSS) (Mezger et al., 2016 and Bertlich et al., 2018). In order to test the applicability of this new proxy in an open-ocean setting, Na/Ca ratios in the planktic foraminifera Trilobatus sacculifer (T. sacculifer Na/Ca) were measured from a suite of sediment core tops spanning a natural salinity gradient from the North Atlantic subtropical gyre to the South Atlantic subtropical gyre. Initial results from …

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Developing A Tourism Opportunity Index Regarding The Prospective Of Overtourism In Nepal, Susan Phuyal Dec 2020

Developing A Tourism Opportunity Index Regarding The Prospective Of Overtourism In Nepal, Susan Phuyal

Graduate Theses/Dissertations

This research explores Nepal's overtourism scenario based on the capacity of a locality to manage sustainable tourism practices. Environmental degradation, local infrastructure degradation, negative tourist experience and local resident responses regarding visitors are the four main variables used in this study to analyze overtourism. In order to analyze the case study of overtourism, we select the three top touristic cities of Nepal, Kathmandu, Pokhara, and Chitwan based on the number of annual visitors. Nepal's case analysis of overtourism conditions reviews the overall threat of over-tourism and establishes a metric by which tourism can be viewed as potentially detrimental to sustainability. …

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Plio-Pleistocene Antarctic Ice-Ocean Interactions In The Ross Sea, Catherine Prunella Nov 2020

Plio-Pleistocene Antarctic Ice-Ocean Interactions In The Ross Sea, Catherine Prunella

USF Tampa Graduate Theses and Dissertations

Warm, intermediate-depth Southern Ocean waters are implicated in recent Antarctic ice mass loss. Direct observations of Antarctic Ice Sheet (AIS) retreat are temporally limited, necessitating paleoceanographic records of ocean-ice interactions during past warm climate intervals. Deepsea and ice-proximal sediments record orbitally-paced glacial-interglacial fluctuations in AIS volume during the Plio-Pleistocene (last 5 million years; Ma), but the total contribution of the AIS and the role of ocean heat in these fluctuations remain unresolved. To address the response of Antarctica’s ice sheets to changing ocean temperatures during the Plio-Pleistocene, International Ocean Discovery Program (IODP) Expedition 374 recovered sediments from the Ross Sea …

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Coral Reef Restoration In The Tropical West Atlantic Amid The Covid-19 Pandemic, Linden Cheek Nov 2020

Coral Reef Restoration In The Tropical West Atlantic Amid The Covid-19 Pandemic, Linden Cheek

USF Tampa Graduate Theses and Dissertations

Climate change is increasing threats to coasts, both from storm surge and sea level rise. Healthy coral reefs provide reduction in storm surges, wave energy, coastal flooding and everyday erosion, and are found across a variety of spatial scales. Given the state of coral reefs worldwide, active Coral Reef Restoration (CRR) in emerging as a necessary component of coastal protection. CRR can be classified as a nature-based solutions (NbS) for coastal protection that also provides a multitude of ecosystem-based services to both humans and other life. Nearly all literature on coral restoration efforts assume a steady-state of human-ecological interactions, but …

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Forest Drought Response Index (Fordri): A New Combined Model To Monitor Forest Drought In The Eastern United States, Tsegaye Tadesse, David Y. Hollinger, Yared A. Bayissa, Mark Svoboda, Brian Fuchs, Beichen Zhang, Getachew Demissie, Brian D. Wardlow, Gil Bohrer, Kenneth L. Clark, Ankur R. Desai, Lianhong Gu, Asko Noormets, Kimberly A. Novick, Andrew D. Richardson Nov 2020

Forest Drought Response Index (Fordri): A New Combined Model To Monitor Forest Drought In The Eastern United States, Tsegaye Tadesse, David Y. Hollinger, Yared A. Bayissa, Mark Svoboda, Brian Fuchs, Beichen Zhang, Getachew Demissie, Brian D. Wardlow, Gil Bohrer, Kenneth L. Clark, Ankur R. Desai, Lianhong Gu, Asko Noormets, Kimberly A. Novick, Andrew D. Richardson

National Drought Mitigation Center: Faculty Publications

Monitoring drought impacts in forest ecosystems is a complex process because forest ecosystems are composed of different species with heterogeneous structural compositions. Even though forest drought status is a key control on the carbon cycle, very few indices exist to monitor and predict forest drought stress. The Forest Drought Indicator (ForDRI) is a new monitoring tool developed by the National Drought Mitigation Center (NDMC) to identify forest drought stress. ForDRI integrates 12 types of data, including satellite, climate, evaporative demand, ground water, and soil moisture, into a single hybrid index to estimate tree stress. The model uses Principal Component Analysis …

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Mass And Number Size Distributions Of Rbc In Snow And Firn Samples From Pine Island Glacier, West Antarctica, Luciano Marquetto, Susan Kaspari, Jefferson Cardia Simões Nov 2020

Mass And Number Size Distributions Of Rbc In Snow And Firn Samples From Pine Island Glacier, West Antarctica, Luciano Marquetto, Susan Kaspari, Jefferson Cardia Simões

Geological Sciences Faculty Scholarship

An extended‐range Single Particle Soot Photometer (SP2) coupled to a Marin‐5 nebulizer was used to measure the refractory black carbon (rBC) mass and number size distributions in 1,004 samples from a West Antarctica snow/firn core. The SP2 was calibrated using Aquadag and a Centrifugal Particle Mass Analyzer for BC particles ranging from 0.5 to 800 fg. Our results indicate a significant contribution of rare, large particles of mass‐equivalent diameter (DBC) > 500 nm to the total rBC mass (36%), while small particles (DBC < 100 nm) are abundant but contribute <8% to total rBC mass. We observed a primary mass median diameter of 162 ± 40 nm, smaller than reported for snow in other regions of the globe but similar to East Antarctica rBC size distributions. In addition, we observed other modes at 673, 1,040, and >1,810 nm (uncontained mode). We compared two sets of samples from different seasons …

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