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Articles 7981 - 8010 of 14008

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Identification And Classification Of Stratospheric Sudden Warming Events, Thomas S. Ehrmann Dec 2012

Identification And Classification Of Stratospheric Sudden Warming Events, Thomas S. Ehrmann

Doctoral Dissertations and Master's Theses

Analysis of northern hemisphere stratospheric data from 1978-2011 is used to identify and classify Stratospheric Sudden Warming events. A total of 41 events are identified during this 33 year period, resulting in an average occurrence rate of 1.24 events/year. No significant variation in the rate is observed during the period analyzed. The average temperature increase during an SSW event is 12 K and the average duration is 32 days. Each identified event is classified as either a vortex displacement or split event and the ratio of displacement to split events is found to be 0.86.


Scientific Basis For Safely Shutting In The Macondo Well After The April 20, 2010 Deepwater Horizon Blowout, Stephen H. Hickman, Paul A. Hsieh, Walter D. Mooney, Catherine B. Enomoto, Philip H. Nelson, Larry A. Mayer, Thomas C. Weber, Kathryn Moran, P. B. Flemings, Marcia Mcnutt Dec 2012

Scientific Basis For Safely Shutting In The Macondo Well After The April 20, 2010 Deepwater Horizon Blowout, Stephen H. Hickman, Paul A. Hsieh, Walter D. Mooney, Catherine B. Enomoto, Philip H. Nelson, Larry A. Mayer, Thomas C. Weber, Kathryn Moran, P. B. Flemings, Marcia Mcnutt

Center for Coastal and Ocean Mapping

As part of the government response to the Deepwater Horizon blowout, a Well Integrity Team evaluated the geologic hazards of shutting in the Macondo Well at the seafloor and determined the conditions under which it could safely be undertaken. Of particular concern was the possibility that, under the anticipated high shut-in pressures, oil could leak out of the well casing below the seafloor. Such a leak could lead to new geologic pathways for hydrocarbon release to the Gulf of Mexico. Evaluating this hazard required analyses of 2D and 3D seismic surveys, seafloor bathymetry, sediment properties, geophysical well logs, and drilling …


A Watershed Scale Evaluation Of Selected Second Generation Biofeedstocks On Water Quality, Gurdeep Singh Dec 2012

A Watershed Scale Evaluation Of Selected Second Generation Biofeedstocks On Water Quality, Gurdeep Singh

Graduate Theses and Dissertations

This study compares a novel simulation approach to the conventional Soil and Water Assessment Tool (SWAT) modeler's approach for targeting biofuel crop production on marginal lands. In conventional SWAT modeling approach, non-spatial definition of hydrological response units (HRUs) results in the simulation of biofuel crops on both marginal and non-marginal land. This study provides an alternative approach in which a marginal-land raster was integrated into the land use and land cover (LULC) raster in such a way that the land uses were divided into marginal and non-marginal components. This modified LULC was used for model setup which resulted in marginal …


Factors Influencing The Spatial And Temporal Distrubtion Of Primary Productivity And Community Respiration In The Mississippi Coastal Estuarine Region, Ryan Anthony Vandermeulen Dec 2012

Factors Influencing The Spatial And Temporal Distrubtion Of Primary Productivity And Community Respiration In The Mississippi Coastal Estuarine Region, Ryan Anthony Vandermeulen

Master's Theses

This study describes the spatial and temporal distribution of net primary productivity (NetPP) and respiration (RESP) in relation to the biogeochemical, optical, and hydrographic variability in the Mississippi Sound and Mississippi Bight over the course of one year. Surface in-situ measurements of NetPP and RESP were regularly determined at two stations by a time-course detection of dissolved oxygen (DO) using novel optode technology. In addition, various biogeochemical, optical, and hydrographic parameters were examined over 14 stations throughout the estuary over a year, using ground and satellite (MODIS Aqua) measurements. In this study, consistently low dissolved inorganic N:P ratios (average N:P …


University Scholar Series: Craig B. Clements, Craig B. Clements Nov 2012

University Scholar Series: Craig B. Clements, Craig B. Clements

University Scholar Series

Groundbreaking Research on Wildfire Weather

On November 28, 2012 Craig B. Clements spoke in the University Scholar Series hosted by Provost Ellen Junn at the Dr. Martin Luther King, Jr. Library. Craig Clements is an associate professor in the Department of Meteorology and Climate Science who received a $900,000 National Science Foundation CAREER grant for his work in tracking atmospheric conditions in and around wildfires. His work will better help predict wildfire behavior and conditions that could lead to increased wildfire danger.


Global Trophic Position Comparison Of Two Dominant Mesopelagic Fish Families (Myctophidae, Stomiidae) Using Amino Acid Nitrogen Isotopic Analyses, C. Anela Choy, Peter C. Davison, Jeffrey C. Drazen, Adrian Flynn, Elizabeth J. Gier, Joel C. Hoffman, Jennifer P. Mcclain-Counts, Todd W. Miller, Brian N. Popp, Steve W. Ross, Tracey Sutton Nov 2012

Global Trophic Position Comparison Of Two Dominant Mesopelagic Fish Families (Myctophidae, Stomiidae) Using Amino Acid Nitrogen Isotopic Analyses, C. Anela Choy, Peter C. Davison, Jeffrey C. Drazen, Adrian Flynn, Elizabeth J. Gier, Joel C. Hoffman, Jennifer P. Mcclain-Counts, Todd W. Miller, Brian N. Popp, Steve W. Ross, Tracey Sutton

Marine & Environmental Sciences Faculty Articles

The δ15N values of organisms are commonly used across diverse ecosystems to estimate trophic position and infer trophic connectivity. We undertook a novel cross-basin comparison of trophic position in two ecologically well-characterized and different groups of dominant mid-water fish consumers using amino acid nitrogen isotope compositions. We found that trophic positions estimated from the δ15N values of individual amino acids are nearly uniform within both families of these fishes across five global regions despite great variability in bulk tissue δ15N values. Regional differences in the δ15N values of phenylalanine confirmed that bulk tissue δ15N values reflect region-specific water mass biogeochemistry …


An Intense Traveling Airglow Front In The Upper Mesosphere–Lower Thermosphere With Characteristics Of A Bore Observed Over Alice Springs, Australia, During A Strong 2 Day Wave Episode, R. L. Walterscheid, J. H. Hecht, L. J. Galinas, Michael P. Hickey Ph.D., I. M. Reid Nov 2012

An Intense Traveling Airglow Front In The Upper Mesosphere–Lower Thermosphere With Characteristics Of A Bore Observed Over Alice Springs, Australia, During A Strong 2 Day Wave Episode, R. L. Walterscheid, J. H. Hecht, L. J. Galinas, Michael P. Hickey Ph.D., I. M. Reid

Publications

The Aerospace Corporation’s Nightglow Imager observed a large step function change in airglow in the form of a traveling front in the OH Meinel (OHM) and O2 atmospheric (O2A) airglow emissions over Alice Springs, Australia, on 2 February 2003. The front exhibited nearly a factor of 2 stepwise increase in the OHM brightness and a stepwise decrease in the O2A brightness. There was significant (~25 K) cooling behind the airglow fronts. The OHM airglow brightness behind the front was among the brightest for Alice Springs that we have measured in 7 years of observations. The event was associated with a …


Agricultural Advisors: A Receptive Audience For Weather And Climate Information?, Linda Stalker Prokopy, Tonya Haigh, Amber Saylor Mase, Jim Angel, Chad Hart, Cody Knutson, Maria Carmen Lemos, Yun Jia Lo, Jean Mcguire, Lois Wright Morton, Jennifer Perron, Dennis Todey, Melissa Widhalm Nov 2012

Agricultural Advisors: A Receptive Audience For Weather And Climate Information?, Linda Stalker Prokopy, Tonya Haigh, Amber Saylor Mase, Jim Angel, Chad Hart, Cody Knutson, Maria Carmen Lemos, Yun Jia Lo, Jean Mcguire, Lois Wright Morton, Jennifer Perron, Dennis Todey, Melissa Widhalm

National Drought Mitigation Center: Faculty Publications

As the climate in the midwestern United States becomes increasingly variable because of global climate change, it is critical to provide tools to the agricultural community to ensure adaptability and profitability of agricultural cropping systems. When used by farmers and their advisors, agricultural decision support tools can reduce uncertainty and risks in the planning, operation, and management decisions of the farm enterprise. Agricultural advisors have historically played a key role in providing information and guidance in these decisions. However, little is known about what these advisors know or think about weather and climate information and their willingness to incorporate this …


Forum Notes: Infrastructure And Utilities Breakout, Hr Adaptation Forum Nov 2012

Forum Notes: Infrastructure And Utilities Breakout, Hr Adaptation Forum

November 16, 2012: Best Practices for Adapting to Sea Level Rise and Flooding

No abstract provided.


Forum Notes: Morning Plenary, Hr Adaptation Forum Nov 2012

Forum Notes: Morning Plenary, Hr Adaptation Forum

November 16, 2012: Best Practices for Adapting to Sea Level Rise and Flooding

No abstract provided.


Agenda, Hr Adaptation Forum Nov 2012

Agenda, Hr Adaptation Forum

November 16, 2012: Best Practices for Adapting to Sea Level Rise and Flooding

No abstract provided.


Climate Change Up Close And Personal: Impacts On Hampton Roads Region, Russell De Young Nov 2012

Climate Change Up Close And Personal: Impacts On Hampton Roads Region, Russell De Young

November 16, 2012: Best Practices for Adapting to Sea Level Rise and Flooding

No abstract provided.


Forum Notes: Land Use And Planning Breakout Group, Hr Adaptation Forum Nov 2012

Forum Notes: Land Use And Planning Breakout Group, Hr Adaptation Forum

November 16, 2012: Best Practices for Adapting to Sea Level Rise and Flooding

No abstract provided.


Forum Notes: Emergency Management, Hr Adaptation Forum Nov 2012

Forum Notes: Emergency Management, Hr Adaptation Forum

November 16, 2012: Best Practices for Adapting to Sea Level Rise and Flooding

No abstract provided.


Adaptation Practices And Lessons Learned, Molly Mitchell Nov 2012

Adaptation Practices And Lessons Learned, Molly Mitchell

November 16, 2012: Best Practices for Adapting to Sea Level Rise and Flooding

No abstract provided.


Sea Level Rise (Slr) Acceleration In The Hampton Roads: A Scientific Perspective, Tal Ezer, Larry Atkinson Nov 2012

Sea Level Rise (Slr) Acceleration In The Hampton Roads: A Scientific Perspective, Tal Ezer, Larry Atkinson

November 16, 2012: Best Practices for Adapting to Sea Level Rise and Flooding

No abstract provided.


Overview Of The 2007 And 2008 Campaigns Conducted As Part Of The Greenland Summit Halogen-HoX Experiment (Gshox), J L. Thomas, Jack E. Dibb, J Stutz, R Von Glasow, Steve Brooks, L Gregory Huey, Barry Lefer Nov 2012

Overview Of The 2007 And 2008 Campaigns Conducted As Part Of The Greenland Summit Halogen-HoX Experiment (Gshox), J L. Thomas, Jack E. Dibb, J Stutz, R Von Glasow, Steve Brooks, L Gregory Huey, Barry Lefer

Earth Sciences

From 10 May through 17 June 2007 and 6 June through 9 July 2008 intensive sampling campaigns at Summit, Greenland confirmed that active bromine chemistry is occurring in and above the snow pack at the highest part of the Greenland ice sheet (72°36´ N, 38°25´ W and 3.2 km above sea level). Direct measurements found BrO and soluble gas phase Br− mixing ratios in the low pptv range on many days (maxima < 10 pptv). Conversion of up to 200 pg m−3 of gaseous elemental mercury (GEM) to reactive gaseous mercury (RGM) and enhanced OH relative to HO2 plus RO2 confirm that active bromine chemistry is …


Climate Change And International Trade: Conflict Or Opportunity?, Joshua Meltzer Nov 2012

Climate Change And International Trade: Conflict Or Opportunity?, Joshua Meltzer

Brookings Scholar Lecture Series

How can international trade negotiations provide incentives or limit progress on domestic and international climate change policy? This presentation will explore how trade negotiations can reduce trade barriers to low carbon produced goods, the implications of the World Trade Organization (WTO) and free trade agreements, and how pricing carbon to reduce greenhouse gas emissions can lead to international competitiveness and carbon leakage concerns. This presentation will consider the implications of the November 6th election on short and long-term climate policy initiatives.


Water Vapor And Temperature Comparisons Between Airs/Amsu-A And In Situ Aircraft Observations From 87°N To 67°S And Sensitivities To Spatial And Temporal Differences, Minghui Diao, Loayeh Jumbam, Justin Sheffield, Eric Wood, Mark Zondlo Nov 2012

Water Vapor And Temperature Comparisons Between Airs/Amsu-A And In Situ Aircraft Observations From 87°N To 67°S And Sensitivities To Spatial And Temporal Differences, Minghui Diao, Loayeh Jumbam, Justin Sheffield, Eric Wood, Mark Zondlo

Faculty Publications, Meteorology and Climate Science

No abstract available.


Microbial Effects On The Production And Transformation Of Surfactants Within The Microlayer And Subsurface Waters In Application To Remote Sensing Techniques, Katie E. Vella Nov 2012

Microbial Effects On The Production And Transformation Of Surfactants Within The Microlayer And Subsurface Waters In Application To Remote Sensing Techniques, Katie E. Vella

HCNSO Student Theses and Dissertations

The sea surface microlayer is a millimeter-scale interfacial layer between the atmosphere and the ocean. A number of studies have suggested that there is a unique ecosystem for marine bacteria in the sea surface microlayer, but little information exists on the microbial community composition of this ecosystem due to sampling complexities. In this work, we present an improved method to sample and compare the bacterial diversity of the sea surface microlayer with that of subsurface water at the same site. Bacterial samples were collected from the sea surface microlayer with a sampling method, which minimized sample contamination from the research …


Climate Change And The Water Crisis In Israel, Lauren Deutsch Nov 2012

Climate Change And The Water Crisis In Israel, Lauren Deutsch

Natural Resources Management and Environmental Sciences

Israel’s water crisis is controlled by the availability and location of water resources that are affected by climate change and geopolitics in southwest Asia. Conflict between Israel and the Palestinian occupied territories in the Gaza Strip and the West Bank have put strains on the allocation of water recourses. The goal of this research was to model how much a change in climate will affect the amount of available freshwater in Israel. Intensive research taken from Israel and the occupied territories was carried out to understand how the amount of precipitation, rainfall, and the rate of evaporation is affected by …


Episodic Recruitment And Climate Analysis Of Ponderosa Pine On The Palmer Divide, Eastern Colorado, William Henry Brenton Jr. Nov 2012

Episodic Recruitment And Climate Analysis Of Ponderosa Pine On The Palmer Divide, Eastern Colorado, William Henry Brenton Jr.

Electronic Theses and Dissertations

Previous recruitment studies on populations of ponderosa pine (Pinus ponderosa P. & C. Lawson) in Colorado have been limited to the western mountains and the Front Range. In this research I used tree-ring data to reconstruct recruitment for ponderosa pine near the eastern limits of its distribution at two sites on the Palmer Divide, Eastern Colorado, to determine the relative climate sensitivity of the two sites, and the extent to which climate or other factors may have influenced recruitment at the sites. The results of the tree-ring analysis suggest that ponderosa pines in more the easterly site lower elevation …


Air-Sea Interface In Hurricane Conditions, Alexander Soloviev, A. Fujimura, Silvia Matt Nov 2012

Air-Sea Interface In Hurricane Conditions, Alexander Soloviev, A. Fujimura, Silvia Matt

Marine & Environmental Sciences Faculty Articles

Improving hurricane prediction models requires better understanding of complex processes taking place at the air-sea interface at high wind speeds. The change of the air-sea interaction regime in hurricane conditions has been linked to the mechanism of direct disruption of the air-sea interface by pressure fluctuations working against the surface tension force. This can be achieved through the Kelvin-Helmholtz type instability. In order to investigate this mechanism, we have conducted a series of 3D numerical experiments using a volume of fluid multiphase model. The experiments were initialized with either a flat interface or short wavelets and wind stress applied at …


Spectral Absorption Of Biomass Burning Aerosol Determined From Retrieved Single Scattering Albedo During Arctas, C A. Corr, S R. Hall, B E. Anderson, Kirk Ullman, A J. Beyersdorf, Kenn L. Thornhill, Michael J. Cubison, Jose L. Jimenez, Armin Wisthaler, Jack E. Dibb Nov 2012

Spectral Absorption Of Biomass Burning Aerosol Determined From Retrieved Single Scattering Albedo During Arctas, C A. Corr, S R. Hall, B E. Anderson, Kirk Ullman, A J. Beyersdorf, Kenn L. Thornhill, Michael J. Cubison, Jose L. Jimenez, Armin Wisthaler, Jack E. Dibb

Earth Sciences

Actinic flux, as well as aerosol chemical and optical properties, were measured aboard the NASA DC-8 aircraft during the ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) mission in Spring and Summer 2008. These measurements were used in a radiative transfer code to retrieve spectral (350-550 nm) aerosol single scattering albedo (SSA) for biomass burning plumes encountered on 17 April and 29 June. Retrieved SSA values were subsequently used to calculate the absorption Angstrom exponent (AAE) over the 350-500 nm range. Both plumes exhibited enhanced spectral absorption with AAE values that exceeded 1 (6.78 ± …


An Analysis Of Deep Convection Initiation Environments, Noah Lock Nov 2012

An Analysis Of Deep Convection Initiation Environments, Noah Lock

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

Initiation is the part of the convective life cycle which is currently least understood and least well forecast. The inability to properly forecast the timing and/or location of deep convection initiation degrades forecast skill, especially during the warm season. The goals of this research are examine the spatiotemporal distribution of thunderstorm initiation points and to determine which atmospheric parameters (and ultimately processes) are most important for the initiation of thunderstorms. The spatiotemporal distribution of thunderstorm initiation points shows the expected peaks during summer and during the afternoon. The warm season also produces significant concentrations of initiation points near mountains, mainly …


A Gap Analysis Of Meteorological Requirements For Commercial Space Operators, Nicholas J. Stapleton Nov 2012

A Gap Analysis Of Meteorological Requirements For Commercial Space Operators, Nicholas J. Stapleton

Doctoral Dissertations and Master's Theses

Commercial space companies will soon be the primary method of launching people and supplies into orbit. Among the critical aspects of space launches are the meteorological concerns. Laws and regulations pertaining to meteorological considerations have been created to ensure the safety of the space industry and those living around spaceports; but, are they adequate? Perhaps the commercial space industry can turn to the commercial aviation industry to help answer that question. Throughout its history, the aviation industry has dealt with lessons learned from mishaps due to failures in understanding the significance of weather impacts on operations. Using lessons from the …


Calibration Of Multibeam Echo Sounders: A Comparison Between Two Methodologies, Carlo Lanzoni, Thomas C. Weber Nov 2012

Calibration Of Multibeam Echo Sounders: A Comparison Between Two Methodologies, Carlo Lanzoni, Thomas C. Weber

Center for Coastal and Ocean Mapping

Multibeam echo sounders (MBES) are widely used in applications like seafloor imaging, fisheries, and habitat mapping. Calibration of acoustic backscatter is an important aspect of understanding and validating the performance of a MBES. Combined transmit/receive beampattern calibrations were performed on a 200 kHz Reson Seabat 7125 MBES in the acoustic tank of the University of New Hampshire utilizing two different methodologies. The first methodology employs fixed standard target spheres and a high accuracy/high resolution rotation mechanism. This method, similar to that proposed by Foote et al ["Protocols forcalibrating multibeam sonar", J. Acoust. Soc. Am. 117(4), 2005], is designed for a …


Potentially Polluting Marine Sites Geodb: An S-100 Geospatial Database As An Effective Contribution To The Protection Of The Marine Environment, Giuseppe Masetti, Brian R. Calder, Lee Alexander Nov 2012

Potentially Polluting Marine Sites Geodb: An S-100 Geospatial Database As An Effective Contribution To The Protection Of The Marine Environment, Giuseppe Masetti, Brian R. Calder, Lee Alexander

Center for Coastal and Ocean Mapping

Potentially Polluting Marine Sites (PPMS) are objects on, or areas of, the seabed that may release pollution in the future. A rationale for, and design of, a geospatial database to inventory and manipu-late PPMS is presented. Built as an S-100 Product Specification, it is specified through human-readable UML diagrams and implemented through machine-readable GML files, and includes auxiliary information such as pollution-control resources and potentially vulnerable sites in order to support analyses of the core data. The design and some aspects of implementation are presented, along with metadata requirements and structure, and a perspective on potential uses of the database.


Characteristics Of Tropospheric Ozone Depletion Events In The Arctic Spring: Analysis Of The Arctas, Arcpac, And Arcions Measurements And Satellite Bro Observations, T P. Kurosu, Yuhang Wang, T P. Kurosu, K Chance, A Rozanov, A Richter, S J. Oltmans, A M. Thompson, Jonathan Hair, Marta Fenn, Andrew Weinheimer, Thomas B. Ryerson, S Solberg, L Gregory Huey, J Liao, Jack E. Dibb, J A. Neuman, J Nowak, B Pierce, M Natarajan, J Al-Saadi Oct 2012

Characteristics Of Tropospheric Ozone Depletion Events In The Arctic Spring: Analysis Of The Arctas, Arcpac, And Arcions Measurements And Satellite Bro Observations, T P. Kurosu, Yuhang Wang, T P. Kurosu, K Chance, A Rozanov, A Richter, S J. Oltmans, A M. Thompson, Jonathan Hair, Marta Fenn, Andrew Weinheimer, Thomas B. Ryerson, S Solberg, L Gregory Huey, J Liao, Jack E. Dibb, J A. Neuman, J Nowak, B Pierce, M Natarajan, J Al-Saadi

Earth Sciences

Arctic ozone depletion events (ODEs) are caused by halogen catalyzed ozone loss. In situ chemistry, advection of ozone-poor air mass, and vertical mixing in the lower troposphere are important factors affecting ODEs. To better characterize the ODEs, we analyze the combined set of surface, ozonesonde, and aircraft in situ measurements of ozone and bromine compounds during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS), the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC), and the Arctic Intensive Ozonesonde Network Study (ARCIONS) experiments (April 2008). Tropospheric BrO columns retrieved from satellite measurements and back …


Short Period Gravity Waves In The Arctic Atmosphere Over Alaska, Michael Negale, Kim Nielsen, Michael J. Taylor, Britta Irving, Richard Collins Oct 2012

Short Period Gravity Waves In The Arctic Atmosphere Over Alaska, Michael Negale, Kim Nielsen, Michael J. Taylor, Britta Irving, Richard Collins

Physics Student Research

The propagation nature and sources of short-period gravity waves have been studied extensively at low and mid-latitudes, while their extent and nature at the polar regions are less known. During the last decade, observations from select sites on the Antarctic continent have revealed a significant presence of these waves over the southern Polar Region as well as shown unexpected dynamical behavior. In contrast, observations over the Arctic region are few and the dynamical behavior is unknown. A recent project was initiated in January 2011 to investigate the presence and dynamics of these waves over interior Alaska. This site provides an …