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2015

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Articles 241 - 270 of 551

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Ua66 Ogden College Of Science & Engineering Newsletter, Cheryl Stevens, Dean May 2015

Ua66 Ogden College Of Science & Engineering Newsletter, Cheryl Stevens, Dean

Ogden College of Science & Engineering Publications

No abstract provided.


Stable Isotopes As A Tool To Characterize Carbon Cycling And Develop Hydrologic Budgets In Mantled Karst Settings, Katherine Knierim May 2015

Stable Isotopes As A Tool To Characterize Carbon Cycling And Develop Hydrologic Budgets In Mantled Karst Settings, Katherine Knierim

Graduate Theses and Dissertations

Isotopes of water (δ2H/δ18O), carbon dioxide (δ13C-CO2), and dissolved inorganic carbon (δ13C-DIC) were used to explore water quality, trace carbon cycling, and quantify recharge sources through mantled karst and into Blowing Spring Cave (BSC). Of the possible sources of contamination in the BSC recharge area, septic-tank effluent was hypothesized to degrade water quality at the spring outlet of BSC because of the dominance of septic tanks for waste treatment, unsuitable topography and soil for septic-tank absorption fields, increased nitrate and chloride concentrations concomitant with increased urbanization, and increased Escherichia coli with discharge. Carbon cycling between the soil and BSC was …


Acute And Chronic Effects Of Large-Vessel Anchoring On Coral Reef Communities Inside A Designated Commercial Anchorage, Lauren Waters May 2015

Acute And Chronic Effects Of Large-Vessel Anchoring On Coral Reef Communities Inside A Designated Commercial Anchorage, Lauren Waters

HCNSO Student Theses and Dissertations

Coral reefs provide economic and environmental services to millions of people as areas for recreation, sources of food, jobs, and shoreline protection; and are now under threat from multiple stresses (NOAA 2002). Anthropogenic impact from acute physical events such as commercial vessel grounding and anchor drags have been well documented throughout the world and southeast Florida. However little data exist on the chronic effects of large commercial vessels anchoring on reef resources. The Port Miami commercial anchorage was designated circa 1927 and was delineated over approximately 700 acres of reef resources. Anchorage use, benthic resources, and substrate composition were surveyed …


Boom Or Bust? Mapping Out The Known Unknowns Of Global Shale Gas Production Potential, Jérôme Hilaire, Nico Bauer, Robert J. Brecha May 2015

Boom Or Bust? Mapping Out The Known Unknowns Of Global Shale Gas Production Potential, Jérôme Hilaire, Nico Bauer, Robert J. Brecha

Physics Faculty Publications

To assess the global production costs of shale gas, we combine global top-down data with detailed bottom-up information. Studies solely based on top-down approaches do not adequately account for the heterogeneity of shale gas deposits and hence, are unlikely to appropriately capture the extraction costs of shale gas. We design and provide an expedient bottom-up method based on publicly available US data to compute the levelized costs of shale gas extraction. Our results indicate the existence of economically attractive areas but also reveal a dramatic cost increase as lower-quality reservoirs are exploited. At the global level, our best estimate suggests …


Adolescent Girls, Human Rights And The Expanding Climate Emergency, Holly G. Atkinson, Judith Bruce May 2015

Adolescent Girls, Human Rights And The Expanding Climate Emergency, Holly G. Atkinson, Judith Bruce

Publications and Research

Many adolescent girls—the poorest girls in the poorest communities—already live in an “emergency.” Humanitarian crises only amplify the call on their coping and caring capacities, while exacerbating their vulnerabilities. The frequency and intensity of emergencies, including natural disasters, conflicts, and infectious disease outbreaks such as Ebola, appear to be growing.1 These emergencies threaten entire communities and whole countries, often with global implications. Many become virtually permanent. The authors urge key actors responding to both the threats and opportunities that climate change poses to understand adolescent girls as exceptionally at risk on the one hand, and as exceptionally resilient and …


Recent Shoreline Erosion Rates Along Black River Bay, Jamaica: Erosion And Recovery After Hurricane Ivan In 2004, Karen Louise Zelzer May 2015

Recent Shoreline Erosion Rates Along Black River Bay, Jamaica: Erosion And Recovery After Hurricane Ivan In 2004, Karen Louise Zelzer

Graduate Theses/Dissertations

Rising sea level is threatening coastal areas, particularly those in the Caribbean which rely heavily on tourism and marine resources to support local economies. The purpose of this study is to analyze shoreline position along the south coast of Jamaica to determine the locations and rates of coastal change. IKONOS satellite imagery sets for 2003, 2007 and 2012 were used to monitor land use and shoreline changes along Black River Bay, including Galleon Beach Fish Sanctuary, in St. Elizabeth, Jamaica. In particular, the effect of Hurricane Ivan in 2004 on shoreline changes was evaluated. Erosion rates were significantly higher during …


Effects Of Landscape Disturbances On Autotrophic Processes Within Arkansas Ozark Streams, Bradley J. Austin May 2015

Effects Of Landscape Disturbances On Autotrophic Processes Within Arkansas Ozark Streams, Bradley J. Austin

Graduate Theses and Dissertations

Land-use change is one of the most widespread human impacts and can influence abiotic and biotic processes within surrounding streams. For example, streams in agricultural and urban watersheds receive greater light and nutrient inputs that can promote increased algal growth and primary production. Natural gas (NG) infrastructure development, a recent land use change in many regions, may also stimulate forested stream primary production, by reducing forest cover and increasing sediments and nutrient transport. I sampled streams across a NG activity gradient for algal biomass and gross primary production (GPP) to assess potential effects of this emerging land-use type. Algal biomass …


Marine Snow Settling Velocities At An Oil Spill Site And A Control Site In The Northern Gulf Of Mexico, Clayton Hugh Dike May 2015

Marine Snow Settling Velocities At An Oil Spill Site And A Control Site In The Northern Gulf Of Mexico, Clayton Hugh Dike

Master's Theses

After budgeting for response efforts and natural processes, over one million barrels of oil from the BP oil spill were unaccounted for. A hypothesis coined "The Dirty Blizzard" formed subsequent to observations of large and numerous oiled marine snow aggregates amidst the surface slick proposed that a large quantity of oil sank to depth via the aggregates. Having reached the seafloor, aggregates were subject to microbial degradation and to redistribution due to bottom currents. To assist in characterizing redistribution of particles near the seafloor, sediment traps, marine snow cameras, and acoustic Doppler current profilers (ADCPs) were deployed at two sites …


Improved Monitoring Of The Changjiang River Plume In The East China Sea During The Monsoon Season Using Satellite Borne L-Band Radiometers, Bumjun Kil May 2015

Improved Monitoring Of The Changjiang River Plume In The East China Sea During The Monsoon Season Using Satellite Borne L-Band Radiometers, Bumjun Kil

Dissertations

Measurement of sea surface salinity (SSS) from Satellite borne L-band (1.4 GHz, 21cm) radiometers (NASA Aquarius/SAC-D and ESA SMOS) in the East China Sea (ECS) is challenging due to the uncertainty of SSS caused by land thermal emissions in the antenna side lobes and because of strong radio frequency interference (RFI) due to illegally emitted man-made sources. RFI contamination in the ECS has gradually decreased because of the on-going international efforts to eliminate broadcasts in the protected L-band radio-astronomy frequency band. The present dissertation focuses on carefully eliminating the remaining RFI contamination in retrieved SSS, and masking out regions close …


Burdens And Benefits Of Climate Change Solutions: A Case Study Of Climate Change Skeptics And Deniers In Rural Nevada, Patricia Dutcher May 2015

Burdens And Benefits Of Climate Change Solutions: A Case Study Of Climate Change Skeptics And Deniers In Rural Nevada, Patricia Dutcher

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation is an ethnographic case study of climate change Doubtfuls and Dismissives with the purpose of understanding their perceptions of water use and renewable energy in the context of a changing climate. I also investigate the information sources and messages they use to understand climate change and climate change solutions. The Global Warming's Six Americas project identifies climate change Doubtfuls and Dismissives as one third of the American public, and an active voice in US climate change policy (Maibach et al, 2009; Leiserowitz et al., 2014). Doubtfuls are people with skeptical attitudes towards anthropogenic climate change, while Dismissives deny …


Framing Reality: Portrayals Of Climate Change In The "Las Vegas Review-Journal", 1997-2014, Jason Ryan Holley May 2015

Framing Reality: Portrayals Of Climate Change In The "Las Vegas Review-Journal", 1997-2014, Jason Ryan Holley

UNLV Theses, Dissertations, Professional Papers, and Capstones

Discussions of human-caused climate change have become an increasingly salient artifact of various media in recent years. With regard to print media in particular, scholars have uncovered general increases in the frequencies with which climate change articles are published, tantamount to the annual reports from the Intergovernmental Panel on Climate Change (IPCC) advocating the detriments of human activities (particularly carbon dioxide emissions) on the natural environment. Among such reports—be they scientific or anecdotal—writers and journalists have had to interpret the ongoing discussions and evidence surrounding climate change, and develop schemas (or frames) in which to situate arguments. These arguments have …


Investigation Of Mountain Waves In The Mesosphere Over The Andes Mountains, Jaime Aguilar Guerrero May 2015

Investigation Of Mountain Waves In The Mesosphere Over The Andes Mountains, Jaime Aguilar Guerrero

Doctoral Dissertations and Master's Theses

An image processing algorithm has been developed to analyze data from a NIR All-Sky Imager of OH airglow emission (from about 87 km altitude), located in the Andes, with the purpose of investigating the atmospheric gravity waves generated when low level wind blows over the high mountains (referred to as Mountain Waves). These types of waves are a special case of atmospheric gravity waves, which carry significant momentum and exert strong forcing to the background upper atmosphere. The imager is located at the Andes Lidar Observatory (ALO) at Cerro Pachón, Chile (30°S, 71°W), which also houses a Na Doppler Lidar …


Trace Element Variations In A Stalagmite From Southwest Mexico: Implications For Paleoclimate, Chad Michael Crotty May 2015

Trace Element Variations In A Stalagmite From Southwest Mexico: Implications For Paleoclimate, Chad Michael Crotty

UNLV Theses, Dissertations, Professional Papers, and Capstones

The combination of stable isotope and trace element concentrations in speleothems has been shown to be a valuable indicator for interpreting paleoclimatic conditions. Anomalous spikes in trace element concentrations have also been shown to indicate anthropogenic environmental changes to the surface, such as deforestation events. In this study, trace element concentrations (24Mg, 25Mg, 84Sr, 88Sr, 137Ba, and 238U) of a stalagmite (JX-6) from Juxtlahuaca Cave, in southwestern Mexico, were measured using an inductively coupled plasma mass spectrometer (ICP-MS). These trace element concentrations were compared to previously analyzed δ18O and δ13C values from JX-6, and to the results of previous studies …


Odu Students Work On Nation's First Climate Change Adapted Neighborhood, Jugal Patel Apr 2015

Odu Students Work On Nation's First Climate Change Adapted Neighborhood, Jugal Patel

News Items

No abstract provided.


Utilizing Remote Sensing Imagery To Monitor Vegetation Change Within World Heritage Sites, Mimi Eve Hatzis Apr 2015

Utilizing Remote Sensing Imagery To Monitor Vegetation Change Within World Heritage Sites, Mimi Eve Hatzis

Theses and Dissertations

ABSTRACT

World Heritage sites provide a glimpse into the stories and civilizations of the past. There are currently 1007 unique World Heritage properties with 779 being classified as cultural sites, 197 as natural sites, and 31 falling into the categories of both cultural and natural sites (UNESCO & World Heritage Centre, 1992-2015). However, of these 1007 World Heritage sites, at least 46 are categorized as in danger and this number continues to grow. These unique and irreplaceable sites are exceptional because of their universality. Consequently, since World Heritage sites belong to all the people of the world and provide inspiration …


Probabilistic Precipitation Estimation With A Satellite Product, Nir Y. Krakauer, Soni M. Pradhanang, Jeeban Panthi, Tarendra Lakhankar, Ajay K. Jha Apr 2015

Probabilistic Precipitation Estimation With A Satellite Product, Nir Y. Krakauer, Soni M. Pradhanang, Jeeban Panthi, Tarendra Lakhankar, Ajay K. Jha

Publications and Research

Satellite-based precipitation products have been shown to represent precipitation well over Nepal at monthly resolution, compared to ground-based stations. Here, we extend our analysis to the daily and subdaily timescales, which are relevant for mapping the hazards caused by storms as well as drought. We compared the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) 3B42RT product with individual stations and with the gridded APHRODITE product to evaluate its ability to retrieve different precipitation intensities. We find that 3B42RT, which is freely available in near real time, has reasonable correspondence with ground-based precipitation products on a daily timescale; rank …


Virginia Sea Grant Charter Signed, Richmond Times-Dispatch Apr 2015

Virginia Sea Grant Charter Signed, Richmond Times-Dispatch

News Items

No abstract provided.


Quantifying The Sensitivity Of Maximum, Limiting, And Potential Tropical Cyclone Intensity To Sst: Observations Versus The Fsu/ Coaps Global Climate Model, Sarah Strazzo, James Elsner, Tim Larow Apr 2015

Quantifying The Sensitivity Of Maximum, Limiting, And Potential Tropical Cyclone Intensity To Sst: Observations Versus The Fsu/ Coaps Global Climate Model, Sarah Strazzo, James Elsner, Tim Larow

Publications

No abstract provided.


Hampton Roads Must Rise To Challenge In Reducing Effects Of Climate Change, Daily Press Apr 2015

Hampton Roads Must Rise To Challenge In Reducing Effects Of Climate Change, Daily Press

News Items

No abstract provided.


Numerical Model Derived Altimeter Correction Maps For Non-Standard Atmospheric Temperature And Pressure, Thomas A. Guinn, Frederick R. Mosher Apr 2015

Numerical Model Derived Altimeter Correction Maps For Non-Standard Atmospheric Temperature And Pressure, Thomas A. Guinn, Frederick R. Mosher

International Journal of Aviation, Aeronautics, and Aerospace

Altimeter corrections for non-standard temperature pose a challenge because accurate calculations require detailed knowledge of the temperature structure of the atmosphere between the surface and the aircraft. By applying basic hypsometric formulae to high resolution numerical model temperature and moisture output, detailed maps of current and forecasted corrected D-values are created. Corrected D-values provide the altitude difference between the true altitude and the indicated altitude from a pressure altimeter. Unlike standard D-values, the corrected D-value corrects for non-standard pressure in addition to non-standard temperature and is therefore useful for flights below class A airspace. Maps of corrected D-value may help …


Dissipation Rate Of Turbulent Kinetic Energy In Diel Vertical Migrations: Comparison Of Ansys Fluent Model To Measurements, Cayla Whitney Dean, Alexander Soloviev, Amy Hirons, Tamara M. Frank, J. D. Wood Apr 2015

Dissipation Rate Of Turbulent Kinetic Energy In Diel Vertical Migrations: Comparison Of Ansys Fluent Model To Measurements, Cayla Whitney Dean, Alexander Soloviev, Amy Hirons, Tamara M. Frank, J. D. Wood

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

Recent studies suggest that diel vertical migrations of zooplankton may have an impact on ocean mixing, though details are not completely clear. A strong sound scattering layer of zooplankton undergoing diel vertical migrations was observed in Saanich Inlet, British Colombia, Canada by Kunze et al. (2006). In this study, a shipboard 200- kHz echosounder was used to track vertical motion of the sound scattering layer, and microstructure profiles were collected to observe turbulence. An increase of dissipation rate of turbulent kinetic energy by four to five orders of magnitude was measured during diel vertical migrations of zooplankton in one case …


A Full-Wave Model For A Binary Gas Thermosphere: Effects Of Thermal Conductivity And Viscosity, Michael P. Hickey Ph.D., R. L. Walterscheid, G. Schubert Apr 2015

A Full-Wave Model For A Binary Gas Thermosphere: Effects Of Thermal Conductivity And Viscosity, Michael P. Hickey Ph.D., R. L. Walterscheid, G. Schubert

Publications

The thermosphere is diffusively separated and behaves as a multiconstituent gas wherein individual species in static equilibrium are each stratified according to their individual scale heights. Gravity waves propagating in the thermosphere cause individual gases to oscillate with different amplitudes and phases. We use a two-gas (N2 and O) full-wave model to examine the roles of thermal conductivity, viscosity, and mutual diffusion on the wave-induced characteristics of both gases. In the lower thermosphere, where the gases are relatively tightly coupled, the major gas (N2) controls the minor gas (O) response. At higher altitudes, the gases become thermally and inertially decoupled, …


Twentieth Century Dust Lows And The Weakening Of The Westerly Winds Over The Tibetan Plateau, Bjorn Grigholm, P. A. Mayewski, S. Kang, Y. Zhang, U. Morgenstern, M. Schwikowski, Susan D. Kaspari, V. Aizen, E. Aizen, N. Takeuchi, K. A. Maasch, S. Birkel, M. Handley, S. Sneed Apr 2015

Twentieth Century Dust Lows And The Weakening Of The Westerly Winds Over The Tibetan Plateau, Bjorn Grigholm, P. A. Mayewski, S. Kang, Y. Zhang, U. Morgenstern, M. Schwikowski, Susan D. Kaspari, V. Aizen, E. Aizen, N. Takeuchi, K. A. Maasch, S. Birkel, M. Handley, S. Sneed

All Faculty Scholarship for the College of the Sciences

Understanding past atmospheric dust variability is necessary to put modern atmospheric dust into historical context and assess the impacts of dust on the climate. In Asia, meteorological data of atmospheric dust is temporally limited, beginning only in the 1950s. High‐resolution ice cores provide the ideal archive for reconstructing preinstrumental atmospheric dust concentrations. Using a ~500 year (1477–1982 A.D.) annually resolved calcium (Ca) dust proxy from a Tibetan Plateau (TP) ice core, we demonstrate the lowest atmospheric dust concentrations in the past ~500 years during the latter twentieth century. Declines in late nineteenth to twentieth century Ca concentrations significantly correspond with …


Accelerated Glacier Melt On Snow Dome, Mount Olympus, Washington, Usa, Due To Deposition Of Black Carbon And Mineral Dust From Wildfire, Susan D. Kaspari, S. Mckenzie Skiles, Ian Delaney, Daniel Dixon, Thomas H. Painter Apr 2015

Accelerated Glacier Melt On Snow Dome, Mount Olympus, Washington, Usa, Due To Deposition Of Black Carbon And Mineral Dust From Wildfire, Susan D. Kaspari, S. Mckenzie Skiles, Ian Delaney, Daniel Dixon, Thomas H. Painter

All Faculty Scholarship for the College of the Sciences

Assessing the potential for black carbon (BC) and dust deposition to reduce albedo and accelerate glacier melt is of interest in Washington because snow and glacier melt are an important source of water resources, and glaciers are retreating. In August 2012 on Snow Dome, Mount Olympus, Washington, we measured snow surface spectral albedo and collected surface snow samples and a 7 m ice core. The snow and ice samples were analyzed for iron (Fe, used as a dust proxy) via inductively coupled plasma sector field mass spectrometry, total impurity content gravimetrically, BC using a single-particle soot photometer (SP2), and charcoal …


Observations Of Mesospheric Gravity Waves Over The Andes, Jonathan Pugmire, Michael Taylor, Yucheng Zhao Apr 2015

Observations Of Mesospheric Gravity Waves Over The Andes, Jonathan Pugmire, Michael Taylor, Yucheng Zhao

Student Research Symposium

Focusing on data from an imager and the SABER instrument aboard the TIMED satellite temperature variances are determined to quantify small-scale gravity waves. IDL software was used to extract all the temperature profile measurements that were measured by SABER within a limited geographical area, centered on our ground-based optical imager at Cerro Pachon, Chile (30.3°S, 70.7°S). Large-scale tidal waves, with wavenumbers 0-6, were removed from each profile revealing the gravity wave perturbations. Temperature variances reveal possible increased wave activity due to mountain waves. Mountain waves in the mesosphere are a relatively unexplored field in aeronomy. They are generated predominantly in …


Estimating Growth And Mortality In Elasmobranchs: Are We Doing It Correctly?, Brian J. Moe Apr 2015

Estimating Growth And Mortality In Elasmobranchs: Are We Doing It Correctly?, Brian J. Moe

HCNSO Student Theses and Dissertations

The instantaneous mortality rate (M) is an important parameter in elasmobranch management and conservation, but is difficult to estimate directly. Thus, indirect estimates based on relatively easily obtained life history parameters are commonly used. Many indirect methods incorporate one or more parameters from the von Bertalanffy growth model (VBGM), which is often criticized for its inability to describe changes in growth associated with maturity. The Lester growth model (LGM) is a biphasic alternative to the VBGM that incorporates trade-offs between reproduction, growth, and survival, and may therefore more accurately estimate M. I used published data from 29 …


Characterizing The Tgf-Lightning Relationship Using Entln, Kareem Omar Apr 2015

Characterizing The Tgf-Lightning Relationship Using Entln, Kareem Omar

Research Horizons Day Posters

No abstract provided.


River Discharge As Affected By Precipitation, Temperature And Soil Characteristics, Susan Kotikot, Kelly Hodgskins Apr 2015

River Discharge As Affected By Precipitation, Temperature And Soil Characteristics, Susan Kotikot, Kelly Hodgskins

Research Horizons Day Posters

No abstract provided.


Uncertainty In Simulating Gross Primary Production Of Cropland Ecosystem From Satellite-Based Models, Wenping Yuan, Wenwen Cai, Anthony L. Nguy-Robertson, Huajun Fang, Andrew E. Suyker, Yang Chen, Wenjie Dong, Shuguang Liu, Haicheng Zhang Apr 2015

Uncertainty In Simulating Gross Primary Production Of Cropland Ecosystem From Satellite-Based Models, Wenping Yuan, Wenwen Cai, Anthony L. Nguy-Robertson, Huajun Fang, Andrew E. Suyker, Yang Chen, Wenjie Dong, Shuguang Liu, Haicheng Zhang

School of Natural Resources: Faculty Publications

Accurate estimates of gross primary production (GPP) for croplands are needed to assess carbon cycle and crop yield. Satellite-based models have been developed to monitor spatial and temporal GPP patterns. However, there are still large uncertainties in estimating cropland GPP. This study compares three light use efficiency (LUE) models (MODIS-GPP, EC-LUE, and VPM) with eddy-covariance measurements at three adjacent AmeriFlux crop sites located near Mead, Nebraska, USA. These sites have different croprotation systems (continuous maize vs. maize and soybean rotated annually) and water management practices (irrigation vs. rainfed). The results reveal several major uncertainties in estimating GPP which need to …


Early Miocene Antarctic Glacial History: New Insights From Heavy Mineral Analysis From Andrill And–2a Drill Core Sediments, Francesco Iacoviello, Giovanna Giorgetti, Isabella Turbanti Memmi, Sandra Passchier Apr 2015

Early Miocene Antarctic Glacial History: New Insights From Heavy Mineral Analysis From Andrill And–2a Drill Core Sediments, Francesco Iacoviello, Giovanna Giorgetti, Isabella Turbanti Memmi, Sandra Passchier

ANDRILL Research and Publications

The present study deals with heavy mineral analysis of late Early Miocene marine sediments recovered in the McMurdo Sound region (Ross Sea, Antarctica) during the ANDRILL— SMS Project in 2007. The main objective is to investigate how heavy mineral assemblages reflect different source rocks and hence different provenance areas. These data contribute to a better understanding of East Antarctica ice dynamics in the Ross Sea sector during the Early Miocene (17.6–20.2 Ma), a time of long-term global warming and sea level rise. The AND-2A drill core recovered several stratigraphic intervals that span from Early Miocene to Pleistocene and it collected …