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Articles 9601 - 9630 of 14028

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Winter 2009, Nsu Oceanographic Center Jan 2009

Winter 2009, Nsu Oceanographic Center

Currents

No abstract provided.

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Spectral Dependence Of Terrestrial Gamma-Ray Flashes On Source Distance, Bryna J. Hazelton, Brian W. Grefenstette, David M. Smith, Joseph R. Dwyer, Xuanmin Shao, Steven A. Cummer, Themis G. Chronis, Erin H. Lay, Robert H. Holzworth Jan 2009

Spectral Dependence Of Terrestrial Gamma-Ray Flashes On Source Distance, Bryna J. Hazelton, Brian W. Grefenstette, David M. Smith, Joseph R. Dwyer, Xuanmin Shao, Steven A. Cummer, Themis G. Chronis, Erin H. Lay, Robert H. Holzworth

Aerospace, Physics, and Space Science Faculty Publications

We use lightning sferics from the World Wide Lightning Location Network to identify storms near 362 Terrestrial Gamma-ray Flashes (TGFs). The combined spectrum of TGFs with storms within 300 km of the sub-satellite point is much harder than the spectrum of TGFs with more distant storms. When these data are compared with simulations of vertically oriented relativistic runaway breakdown, it is found that the most likely model has a source altitude of 15 km and a wide-beam geometry. We find four associations of TGFs with individual sferics geolocated to positions more than 300 km from the sub-satellite point and show …

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African Easterly Waves And Convection, Gareth James Berry Jan 2009

African Easterly Waves And Convection, Gareth James Berry

Legacy Theses & Dissertations (2009 - 2024)

In this research the physical mechanisms relating synoptic scale African Easterly Waves (AEWs) and convection are explored using a variety of analysis techniques.

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Measurement Of Atmospheric Ammonia Species : Development, Validation, And Field Applications Of An Analytical Method, Jian Hou Jan 2009

Measurement Of Atmospheric Ammonia Species : Development, Validation, And Field Applications Of An Analytical Method, Jian Hou

Legacy Theses & Dissertations (2009 - 2024)

Ammonia is the primary base in the atmosphere. It reacts readily with atmospheric acids such as sulfuric acid, nitric acid, and hydrochloric acid to form ammonium salts that occur predominantly in the fine aerosol particle (PM2.5) fraction. The ability to measure ammonia species (NHx, the sum of gaseous NH3 and particulate NH4+) is essential for the investigation of atmospheric behaviors of NHx. In this dissertation work, a highly sensitive technique has been developed for the measurement of atmospheric NHx species. The method is based on aqueous scrubbing of the atmospheric NH3 and NH4+ using …

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Toxicity Of Polybrominated Diphenyl Ethers (De-71) In Chicken (Gallus Gallus), Mallard (Anas Platyrhynchos), And American Kestrel (Falco Sparverius) Embryos And Hatchlings, Moira A. Mckernan, Barnett A. Rattner, Robert C. Hales, Mary Ann Ottinger Jan 2009

Toxicity Of Polybrominated Diphenyl Ethers (De-71) In Chicken (Gallus Gallus), Mallard (Anas Platyrhynchos), And American Kestrel (Falco Sparverius) Embryos And Hatchlings, Moira A. Mckernan, Barnett A. Rattner, Robert C. Hales, Mary Ann Ottinger

United States Geological Survey: Staff Publications

Embryonic survival, pipping and hatching success, and sublethal biochemical, endocrine, and histological endpoints were examined in hatchling chickens (Gallus gallus), mallards (Anas platyrhynchos), and American kestrels (Falco sparverius) following air cell administration of a pentabrominated diphenyl ether (penta-BDE; DE-71) mixture (0.01–20 µg/g egg) or polychlorinated biphenyl (PCB) congener 126 (3,3’,4,4’,5-pentachlorobiphenyl; 0.002 µg/g egg). The penta-BDE decreased pipping and hatching success at concentrations of 10 and 20 µg/g egg in kestrels but had no effect on survival endpoints in chickens or mallards. Sublethal effects in hatchling chickens included ethoxyresorufin-O-dealkylase (EROD) induction and histological …

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The Malina Oceanographic Expedition: How Do Changes In Ice Cover, Permafrost And Uv Radiation Impact On Biodiversity And Biogeochemical Fluxes In The Arctic Ocean?, Phillippe Massicotte, Rainer Amon, David Antoine, Philippe Archambault, Sergio Balzano, Simon Bélanger, Ronald Benner, Dominique Boeuf, Annick Bricaud, Flavienne Bruyant, Gwenaëlle Chaillou, Malik Malik, Bruno Charrière, Jing Chen, Hervé Claustre, Pierre Coupel, Nicole Delsaut, David Doxaran, Et. Al. Jan 2009

The Malina Oceanographic Expedition: How Do Changes In Ice Cover, Permafrost And Uv Radiation Impact On Biodiversity And Biogeochemical Fluxes In The Arctic Ocean?, Phillippe Massicotte, Rainer Amon, David Antoine, Philippe Archambault, Sergio Balzano, Simon Bélanger, Ronald Benner, Dominique Boeuf, Annick Bricaud, Flavienne Bruyant, Gwenaëlle Chaillou, Malik Malik, Bruno Charrière, Jing Chen, Hervé Claustre, Pierre Coupel, Nicole Delsaut, David Doxaran, Et. Al.

Faculty Publications

The MALINA oceanographic campaign was conducted during summer 2009 to investigate the carbon stocks and the processes controlling the carbon fluxes in the Mackenzie River estuary and the Beaufort Sea. During the campaign, an extensive suite of physical, chemical and biological variables was measured across seven shelf–basin transects (south-north) to capture the meridional gradient between the estuary and the open ocean. Key variables such as temperature, absolute salinity, radiance, irradiance, nutrient concentrations, chlorophyll-a concentration, bacteria, phytoplankton and zooplankton abundance and taxonomy, and carbon stocks and fluxes were routinely measured onboard the Canadian research icebreaker CCGS Amundsen and from a barge …

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Patterns Of Spiny Lobster (Panulirus Argus) Postlarval Recruitment In The Carribbean: A Crtr Project, Mark J. Butler Iv, Angela M. Mojica, Eloy Sosa-Cordero, Marines Millet, Paul Sanchez-Navarro, Miguel A. Maldonado, Juan Posada, Bladimir Rodriguez, Carlos M. Rivas, Adrian Oviedo, Marcio Arrone, Martha Prada, Nick Bach, Nilda Jimenez, Maria Del Carmen Garcia-Rivas, Kirah Forman, Donald C. Behringer Jr., Thomas Matthews, Claire Paris, Robert Cowen Jan 2009

Patterns Of Spiny Lobster (Panulirus Argus) Postlarval Recruitment In The Carribbean: A Crtr Project, Mark J. Butler Iv, Angela M. Mojica, Eloy Sosa-Cordero, Marines Millet, Paul Sanchez-Navarro, Miguel A. Maldonado, Juan Posada, Bladimir Rodriguez, Carlos M. Rivas, Adrian Oviedo, Marcio Arrone, Martha Prada, Nick Bach, Nilda Jimenez, Maria Del Carmen Garcia-Rivas, Kirah Forman, Donald C. Behringer Jr., Thomas Matthews, Claire Paris, Robert Cowen

Biological Sciences Faculty Publications

As part of the Coral Reef Targeted Research (CRTR) Program, a partnership between the Global Environment Facility and the World Bank, our research team examined the recruitment patterns of Caribbean spiny lobster (Panulirus argus) postlarvae among regions in the Caribbean, with a particular focus on Mesoamerica. Our goal was to collect comparable information on postlarval supply among regions and to provide data to test predictions of connectivity generated from a coupled biophysical oceanographic model of lobster larval dispersal. Here we present the results of the postlarval recruitment monitoring program. We monitored the catch of postlarvae on Witham-style collectors …

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Understanding How Disease And Environment Combine To Structure Resistance In Estuarine Bivalve Populations, Eileen E. Hofmann, David Bushek, Susan E. Ford, Ximing Guo, Dale Haidvogel, Dennis Hedgecock, John M. Klinck, Coren Milbury, Diego Narvaez, Eric Powell, Yongping Wang, Zhiren Wang, Liusuo Zhang Jan 2009

Understanding How Disease And Environment Combine To Structure Resistance In Estuarine Bivalve Populations, Eileen E. Hofmann, David Bushek, Susan E. Ford, Ximing Guo, Dale Haidvogel, Dennis Hedgecock, John M. Klinck, Coren Milbury, Diego Narvaez, Eric Powell, Yongping Wang, Zhiren Wang, Liusuo Zhang

CCPO Publications

Delaware Bay oyster (Crassostrea virginica) populations are influenced by two lethal parasites that cause Dermo and MSX diseases. As part of the US National Science Foundation Ecology of Infectious Diseases initiative, a program developed for Delaware Bay focuses on understanding how oyster population genetics and population dynamics interact with the environment and these parasites to structure he host populations, and how these interactions might modified by climate change. Laboratory and field studies undertaken during this program include identifying genes related to MSX and Dermo disease resistance, potential regions for refugia and the mechanisms that allow them to exist, …

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Combining Remote Sensing Data And An Inundation Model To Map Tidal Mudflat Regions And Improve Flood Predictions: A Proof Of Concept Demonstration In Cook Inlet, Alaska, Tal Ezer, Hua Liu Jan 2009

Combining Remote Sensing Data And An Inundation Model To Map Tidal Mudflat Regions And Improve Flood Predictions: A Proof Of Concept Demonstration In Cook Inlet, Alaska, Tal Ezer, Hua Liu

CCPO Publications

Accurate flood predictions require high resolution inundation numerical models and detailed coastal and land topography data. However, such data are not always available. A new method to obtain topographic information of flood zones from remote sensing data is demonstrated here for Cook Inlet, Alaska, where tidal range reaches 8-10 m. The moving shoreline is detected from analysis of water coverage in satellite images taken at different tidal stages, and then the shoreline data from different times are combined with water level data from observations and models to produce new topographic maps of previously unobserved mudflats. The remote sensing-based analysis provides …

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Variations In Sea Surface Roughness Induced By The 2004 Sumatra-Andaman Tsunami, O. A. Godin, V. G. Irisov, R. R. Leben, B. D. Hamlington, G. A. Wick Jan 2009

Variations In Sea Surface Roughness Induced By The 2004 Sumatra-Andaman Tsunami, O. A. Godin, V. G. Irisov, R. R. Leben, B. D. Hamlington, G. A. Wick

CCPO Publications

Observations of tsunamis away from shore are critically important for improving early warning systems and understanding of tsunami generation and propagation. Tsunamis are difficult to detect and measure in the open ocean because the wave amplitude there is much smaller than it is close to shore. Currently, tsunami observations in deep water rely on measurements of variations in the sea surface height or bottom pressure. Here we demonstrate that there exists a different observable, specifically, ocean surface roughness, which can be used to reveal tsunamis away from shore. The first detailed measurements of the tsunami effect on sea surface height …

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Multiple Stable Reference Points In Oyster Populations: Biological Relationships For The Eastern Oyster (Crassostrea Virginica) In Delaware Bay, Eric N. Powell, John M. Klinck, Kathryn A. Ashton-Alcox, John N. Kraeuter Jan 2009

Multiple Stable Reference Points In Oyster Populations: Biological Relationships For The Eastern Oyster (Crassostrea Virginica) In Delaware Bay, Eric N. Powell, John M. Klinck, Kathryn A. Ashton-Alcox, John N. Kraeuter

CCPO Publications

In the first of two companion papers, a 54-yr time series for the oyster population in the New Jersey waters of Delaware Bay was analyzed to develop biological relationships necessary to evaluate maximum sustainable yield (MSY) reference points and to consider how multiple stable points affect reference point-based management. The time series encompassed two regime shifts, one circa 1970 that ushered in a 15-yr period of high abundance, and a second in 1985 that ushered in a 20-yr period of low abundance. The intervening and succeeding periods have the attributes of alternate stable states. The biological relationships between abundance, recruitment, …

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Enso And Variability Of The Antarctic Peninsula Pelagic Marine Ecosystem, Valerie J. Loeb, Eileen E. Hofmann, John M. Klinck, Osmund Holm-Hansen, Warren B. White Jan 2009

Enso And Variability Of The Antarctic Peninsula Pelagic Marine Ecosystem, Valerie J. Loeb, Eileen E. Hofmann, John M. Klinck, Osmund Holm-Hansen, Warren B. White

CCPO Publications

The West Antarctic Peninsula region is an important source of Antarctic krill (Euphausia superba) in the Southern Ocean. From 1980-2004 abundance and concentration of phytoplankton and zooplankton, krill reproductive and recruitment success and seasonal sea ice extent here were significantly correlated with the atmospheric Southern Oscillation Index and exhibited three- to five-year frequencies characteristic of El Nino-Southern Oscillation (ENSO) variability. This linkage was associated with movements of the Southern Antarctic Circumpolar Current Front and Boundary, a changing influence of Antarctic Circumpolar Current and Weddell Sea waters, and eastward versus westward flow and mixing processes that are consistent with forcing by …

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Southern Ocean Globec Research And The Future, Eileen Hofmann Jan 2009

Southern Ocean Globec Research And The Future, Eileen Hofmann

CCPO Publications

(First paragraph) The International Global Ocean Ecosystems Dynamics (GLOBEC) Programme will end in early 2010, after almost 20 years. GLOBEC science has provided fundamental changes in our understanding of the scales of interactions in marine ecosystems, alternative views of marine food webs, and the influence of humans in marine ecosystem processes. Since Southern Ocean GLOBEC (SO GLOBEC) was one of the regional research programmes it is appropriate to reflect on i) its specific contributions, ii) how these might guide future Southern Ocean research, and iii) the key gaps for our future understanding of Southern Ocean ecosystems and the impact that …

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Profiles Of Ocean Surface Heating (Posh): A New Model Of Upper Ocean Diurnal Warming, Chelle L. Gentemann, Peter J. Minnett, Brian Ward Jan 2009

Profiles Of Ocean Surface Heating (Posh): A New Model Of Upper Ocean Diurnal Warming, Chelle L. Gentemann, Peter J. Minnett, Brian Ward

CCPO Publications

Shipboard radiometric measurements of diurnal warming at the ocean surface and profiles through the diurnal thermocline were utilized to assess the temporal and vertical variability and to develop a new physics-based model of near-surface warming. The measurements and modeled diurnal warming were compared, with the goal of comprehensively evaluating differences between the data and model results. On the basis of these results, the diurnal model was refined while attempting to maintain agreement with the measurements. Simplified bulk models commonly do not provide information on the vertical structure within the warm layer, but this new model predicts the vertical temperature profile …

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Regional Characterisation Of Hard-Bottom Nursery Habitat For Juvenile Caribbean Spiny Lobster (Panulirus Argus) Using Rapid Assessment Techniques, Rodney D. Bertelsen, Mark J. Butler Iv, William F. Herrnkind, John H. Hunt Jan 2009

Regional Characterisation Of Hard-Bottom Nursery Habitat For Juvenile Caribbean Spiny Lobster (Panulirus Argus) Using Rapid Assessment Techniques, Rodney D. Bertelsen, Mark J. Butler Iv, William F. Herrnkind, John H. Hunt

Biological Sciences Faculty Publications

Shallow, hard-bottom habitat constitutes approximately 30% of the coastal waters of south Florida, United States, yet it is a chronically understudied feature of the marine seascape in this region. In this study, we characterised the general biogeographic and structural features of shallow benthic hard-bottom communities in the Florida Keys, and related those to the abundance of juvenile Caribbean spiny lobster (Panulirus argus), the target of one of Florida's most economically valuable fisheries. We used rapid assessment techniques to survey more than 100 hard-bottom sites in the Florida Keys to estimate the percentage bottom coverage of vegetation (seagrass and …

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Electrospray And Photoionization Mass Spectrometry For The Characterization Of Organic Matter In Natural Waters: A Qualitative Assessment, William C. Hockaday, Jeremiah M. Pucell, Alan G. Marshall, Jeffery A. Baldock, Patrick G. Hatcher Jan 2009

Electrospray And Photoionization Mass Spectrometry For The Characterization Of Organic Matter In Natural Waters: A Qualitative Assessment, William C. Hockaday, Jeremiah M. Pucell, Alan G. Marshall, Jeffery A. Baldock, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

Fourier-transform ion cyclotron resonance mass spectrometry (MS) has demonstrated potential to revolutionize the fields of limnology and chemical oceanography by identifying the individual molecular components of organic matter in natural waters. The use of MS for this purpose is made possible by the electrospray technique which successfully ionizes polar, nonvolatile organic molecules. Another recently developed ion source, atmospheric pressure photoionization (APPI), extends MS capabilities to less polar molecules. This article presents early results on the application of APPI MS to natural organic matter. We compare APPI MS and electrospray MS data for dissolved organic matter from Lake Drummond (Virginia, USA). …

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Photochemical Degradation Of Dissolved Organic Matter And Dissolved Lignin Phenols From The Congo River, Robert G. M. Spencer, Aron Stubbins, Peter J. Hernes, Kenneth Mopper, Anthony K. Aufdenkampe, Rachael Y. Dyda, Vincent L. Mwamba, Arthur M. Mangangu, Jose N. Wabakanghanzi, Johan Six Jan 2009

Photochemical Degradation Of Dissolved Organic Matter And Dissolved Lignin Phenols From The Congo River, Robert G. M. Spencer, Aron Stubbins, Peter J. Hernes, Kenneth Mopper, Anthony K. Aufdenkampe, Rachael Y. Dyda, Vincent L. Mwamba, Arthur M. Mangangu, Jose N. Wabakanghanzi, Johan Six

Chemistry & Biochemistry Faculty Publications

Photochemical degradation of Congo River dissolved organic matter (DOM) was investigated to examine the fate of terrigenous DOM derived from tropical ecosystems. Tropical riverine DOM receives greater exposure to solar radiation, particularly in large river plumes discharging directly into the open ocean. Initial Congo River DOM exhibited dissolved organic carbon (DOC) concentration and compositional characteristics typical of organic rich blackwater systems. During a 57 day irradiation experiment, Congo River DOM was shown to be highly photoreactive with a decrease in DOC, chromophoric DOM (CDOM), lignin phenol concentrations (Σ8) and carbon-normalized yields (Λ8), equivalent to losses of ~45, 85–95, >95 and …

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Two Contrasting Dust-Dominant Periods Over India Observed From Modis And Calipso Data, Ritesh Gautam, Zhaoyan Liu, Ramesh P. Singh, N. Christina Hsu Jan 2009

Two Contrasting Dust-Dominant Periods Over India Observed From Modis And Calipso Data, Ritesh Gautam, Zhaoyan Liu, Ramesh P. Singh, N. Christina Hsu

Mathematics, Physics, and Computer Science Faculty Articles and Research

Each year, prior to the onset of the Indian Summer Monsoon, the Gangetic Plains (GP), bounded by the high-altitude Himalayan mountains, are strongly influenced by the transport of dust outbreaks originating in the northwestern desert in India (known as the Thar Desert). Dust particles constitute the bulk of the regional aerosol loading which peaks annually during the pre-monsoon season. This paper integrates observations from space-borne sensors, namely MODIS and CALIPSO, together with ground sunphotometer measurements, to infer dust loading in the pre-monsoon aerosol build-up over source and sink regions in northern India. Detailed aerosol characterization from the synergetic observational assessment …

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Melting Of Major Glaciers In The Western Himalayas: Evidence Of Climatic Changes From Long Term Msu Derived Tropospheric Temperature Trend (1979-2008), Anup K. Prasad, Keun-Hang Susan Yang, Hesham El-Askary, Menas Kafatos Jan 2009

Melting Of Major Glaciers In The Western Himalayas: Evidence Of Climatic Changes From Long Term Msu Derived Tropospheric Temperature Trend (1979-2008), Anup K. Prasad, Keun-Hang Susan Yang, Hesham El-Askary, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Global warming or the increase of the surface and atmospheric temperatures of the Earth, is increasingly discernible in the polar, sub-polar and major land glacial areas. The Himalayan and Tibetan Plateau Glaciers, which are the largest glaciers outside of the Polar regions, are showing a large-scale decrease of snow cover and an extensive glacial retreat. These glaciers such as Siachen and Gangotri are a major water resource for Asia as they feed major rivers such as the Indus, Ganga and Brahmaputra. Due to scarcity of ground measuring stations, the long-term observations of atmospheric temperatures acquired from the Microwave Sounding Unit …

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The Potential Of The Synergistic Use Of Passive And Active Remote Sensing Measurements For The Validation Of A Regional Dust Model, V. Amiridis, Menas Kafatos, M. Perez, S. Kazadzis, E. Gerasopoulos, R. E. Mamouri, A. Papayannis, P. Kokkalis, E. Giannakaki, S. Basart, I. Daglis, C S. Zerefos Jan 2009

The Potential Of The Synergistic Use Of Passive And Active Remote Sensing Measurements For The Validation Of A Regional Dust Model, V. Amiridis, Menas Kafatos, M. Perez, S. Kazadzis, E. Gerasopoulos, R. E. Mamouri, A. Papayannis, P. Kokkalis, E. Giannakaki, S. Basart, I. Daglis, C S. Zerefos

Mathematics, Physics, and Computer Science Faculty Articles and Research

A long-lasting Saharan dust event affected Europe on 18–23 May 2008. Dust was present in the free troposphere over Greece, in height ranges between the surface and approximately 4–5 km above sea level. The event was monitored by ground-based CIMEL sunphotometric and multi-wavelength combined backscatter/Raman lidar measurements over Athens, Greece. The dust event had the maximum of its intensity on 20 May. Three-dimensional dust spatial distribution over Greece on that day is presented through satellite synergy of passive and active remote sensing using MODIS and CALIPSO data, respectively. For the period under study, the ground-based measurements are used to characterize …

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Transport Of Dust And Anthropogenic Aerosols Across Alexandria, Egypt, Hesham El-Askary, R. Farouk, C. Ichoku, Menas Kafatos Jan 2009

Transport Of Dust And Anthropogenic Aerosols Across Alexandria, Egypt, Hesham El-Askary, R. Farouk, C. Ichoku, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The flow of pollutants from Europe and desert dust to Europe from the Sahara desert both affects the air quality of the coastal regions of Egypt. As such, measurements from both ground and satellite observations assume great importance to ascertain the conditions and flow affecting the Nile Delta and the large city of Alexandria. We note that special weather conditions prevailing in the Mediterranean Sea result in a westerly wind flow pattern during spring and from North to South during the summer. Such flow patterns transport dust-loaded and polluted air masses from the Sahara desert and Europe, respectively, through Alexandria, …

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Enhanced Pre-Monsoon Warming Over The Himalayan-Gangetic Region From 1979-2007, Ritesh Gautam, N. C. Hsu, K. M. Lau, S.-C. Tsay, Menas Kafatos Jan 2009

Enhanced Pre-Monsoon Warming Over The Himalayan-Gangetic Region From 1979-2007, Ritesh Gautam, N. C. Hsu, K. M. Lau, S.-C. Tsay, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Fundamental to the onset of the Indian Summer Monsoon is the land-sea thermal gradient from the Indian Ocean to the Himalayas-Tibetan Plateau (HTP). The timing of the onset is strongly controlled by the meridional tropospheric temperature gradient due to the rapid premonsoon heating of the HTP compared to the relatively cooler Indian Ocean. Analysis of tropospheric temperatures from the longest available record of microwave satellite measurements reveals widespread warming over the Himalayan-Gangetic region and consequent strengthening of the land-sea thermal gradient. This trend is most pronounced in the pre-monsoon season, resulting in a warming of 2.7 C in the 29-year …

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Numerical Simulations Of The Impacts Of The Saharan Air Layer On Atlantic Tropical Cyclone Development, Donglian Sun, K. M. Lau, Menas Kafatos, Z. Boybeyi, G. Leptoukh, C. Yang, Ruixin Yang Jan 2009

Numerical Simulations Of The Impacts Of The Saharan Air Layer On Atlantic Tropical Cyclone Development, Donglian Sun, K. M. Lau, Menas Kafatos, Z. Boybeyi, G. Leptoukh, C. Yang, Ruixin Yang

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this study, the role of the Saharan air layer (SAL) is investigated in the development and intensification of tropical cyclones (TCs) via modifying environmental stability and moisture, using multisensor satellite data, long-term TC track and intensity records, dust data, and numerical simulations with a state-of-the-art Weather Research and Forecasting model (WRF). The long-term relationship between dust and Atlantic TC activity shows that dust aerosols are negatively associated with hurricane activity in the Atlantic basin, especially with the major hurricanes in the western Atlantic region. Numerical simulations with the WRF for specific cases during the NASA African Monsoon Multidisciplinary Analyses …

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Inter-Continental Transport Of Dust And Pollution Aerosols Across Alexandria, Egypt, Hesham El-Askary, R. Farouk, C. Ichoku, Menas Kafatos Jan 2009

Inter-Continental Transport Of Dust And Pollution Aerosols Across Alexandria, Egypt, Hesham El-Askary, R. Farouk, C. Ichoku, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The flow of pollutants from Europe and desert dust to Europe from the Sahara desert both affects the air quality of the coastal regions of Egypt. As such, measurements from both ground and satellite observations assume great importance to ascertain the conditions and flow affecting the Nile Delta and the large city of Alexandria. We note that special weather conditions prevailing in the Mediterranean Sea result in a westerly wind flow pattern during spring and from North to South during the summer. Such flow patterns transport dust-loaded and polluted air masses from the Sahara desert and Europe, respectively, through Alexandria, …

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Atmospheric Soluble Dust Records From A Tibetan Ice Core: Possible Climate Proxies And Teleconnection With The Pacific Decadal Oscillation, B. Grigholm, P. A. Mayewski, S. Kang, Y. Zhang, Susan Kaspari, S. B. Sneed, Q. Zhang Jan 2009

Atmospheric Soluble Dust Records From A Tibetan Ice Core: Possible Climate Proxies And Teleconnection With The Pacific Decadal Oscillation, B. Grigholm, P. A. Mayewski, S. Kang, Y. Zhang, Susan Kaspari, S. B. Sneed, Q. Zhang

Geological Sciences Faculty Scholarship

In autumn 2005, a joint expedition between the University of Maine and the Institute of Tibetan Plateau Research recovered three ice cores from Guoqu Glacier (33°34′37.8″N, 91°10′35.3″E, 5720 m above sea level) on the northern side of Mt. Geladaindong, central Tibetan Plateau. Isotopes (δ18O), major soluble ions (Na+, K+, Mg2+, Ca2+, Cl−, NO3−, SO42−), and radionuclide (β‐activity) measurements from one of the cores revealed a 70‐year record (1935–2005). Statistical analysis of major ion time series suggests that atmospheric soluble …

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Hydrodynamic Response To Cold Fronts Along The Louisiana Coast, Zhixuan Feng Jan 2009

Hydrodynamic Response To Cold Fronts Along The Louisiana Coast, Zhixuan Feng

LSU Master's Theses

Cold fronts play important roles in flushing water out of the Louisiana estuaries. This study is aimed at examining the impact of cold front passages on the hydrodynamics in autumn-winter-spring of 2006-2007, and tries to determine the geographic difference, correlation and relative importance of winds, tides, and river discharge on water level variability and flow field. The amplitude spectra of water level reveal that diurnal tides dominate most stations. Areas west of 91°W have relatively high semidiurnal tides. The subtidal fluctuations are mainly wind-driven. Only the station in the Atchafalaya River shows obvious response to the spring flood of the …

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Subaqueous, Hurricane-Initiated Shelf Failure Morphodynamics Along The Mississippi River Delta Front, North-Central Gulf Of Mexico, Walter Scott Guidroz Jan 2009

Subaqueous, Hurricane-Initiated Shelf Failure Morphodynamics Along The Mississippi River Delta Front, North-Central Gulf Of Mexico, Walter Scott Guidroz

LSU Doctoral Dissertations

Seafloor instability along the Mississippi River Delta Front (MRDF) gained renewed attention with the landfall of Hurricanes Ivan (2004) and Katrina (2005). Traditional root causes for MRDF shelf failure were exacerbated by sea-state conditions associated with these severe tropical cyclones and their interaction with the seafloor. These conditions were characterized by large waves, long wave periods and wave-induced turbulence in the bottom boundary layer and throughout the water column. An evaluation of local and regional MRDF bathymetry data revealed substantial changes in seafloor elevation and the immediate subsurface sediment profile, hypothesized as the end result of cyclic wave-seafloor interaction, seafloor …

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The Role Of Climate Variability And Riverine Pulsing In The Community Dynamics Of Estuarine Nekton In Breton Sound, Louisiana, Bryan Patrick Piazza Jan 2009

The Role Of Climate Variability And Riverine Pulsing In The Community Dynamics Of Estuarine Nekton In Breton Sound, Louisiana, Bryan Patrick Piazza

LSU Doctoral Dissertations

Climate controls biotic community composition at multiple spatiotemporal scales through variability in environmental control mechanisms (assembly filters). This research investigated the role of climate variability in the community dynamics of estuarine nekton in Breton Sound estuary, Louisiana, and, specifically the effects of El Niño Southern Oscillation (ENSO), freshwater discharge, and a tropical cyclone. A teleconnection was found between ENSO and juvenile brown shrimp (Farfantepenaeus aztecus) abundance in Breton Sound from 1988 – 2007. ENSO affected winter weather conditions (air pressure, temperature and precipitation), and spring brown shrimp abundance in Breton Sound. Juvenile brown shrimp abundance lagged ENSO by …

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Remediating Impacts Of Global Climate Change-Induced Submergence On Salt Marsh Ecosystem Functions, Camille Lafosse Stagg Jan 2009

Remediating Impacts Of Global Climate Change-Induced Submergence On Salt Marsh Ecosystem Functions, Camille Lafosse Stagg

LSU Doctoral Dissertations

Impacts of global climate change, such as sea level rise and severe drought, have altered the hydrology of coastal salt marshes resulting in submergence and subsequent degradation of ecosystem function. A potential method of rehabilitating these systems is the addition of sediment-slurries to increase the elevation of the marsh surface, thus ameliorating the effects of excessive inundation. Although this technique is growing in popularity, the successful restoration of ecological function after sediment addition has received little attention. The purpose of this research was to determine if sediment subsidized salt marshes are functionally equivalent to natural marshes and whether salt marshes …

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Oil Platforms And Red Snapper Movement And Behavior, Michael Mcdonough Jan 2009

Oil Platforms And Red Snapper Movement And Behavior, Michael Mcdonough

LSU Master's Theses

Understanding the behavior, including movement, of red snapper (Lutjanus campechanus), around and among the many oil and gas platforms in the northern Gulf of Mexico (GOM) is crucial to the management of this important commercial and recreational species. What role oil and gas production platforms play in the attraction vs. production continuum for red snapper is unknown, but it is certain these large structures have a role at some life history stage. We used the VRAP acoustic telemetry system to track red snapper around two platforms in the GOM in 2005 and 2006. Fish detections per hour generally decreased over …

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