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- Buoy observations (2)
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Articles 1 - 10 of 10
Full-Text Articles in Entire DC Network
Transport Of Nordic Seas Overflow Water Into And Within The Irminger Sea: An Eddy-Resolving Simulation And Observations, Xiaobiao Xu, W.J. Schmitz Jr., Harley E. Hulbert, Patrick J. Hogan, Eric P. Chassignet, H.M. Van Aken
Transport Of Nordic Seas Overflow Water Into And Within The Irminger Sea: An Eddy-Resolving Simulation And Observations, Xiaobiao Xu, W.J. Schmitz Jr., Harley E. Hulbert, Patrick J. Hogan, Eric P. Chassignet, H.M. Van Aken
Faculty Publications
Results from a climatologically forced, eddy-resolving (1/12 degrees) Atlantic simulation using the Hybrid Coordinate Ocean Model help clarify some presently unresolved connections between volume transports of Nordic Seas overflow water at key locations in the northernmost North Atlantic Ocean. The model results demonstrate that, in addition to the known westward flow through the Charlie Gibbs Fracture Zone (CGFZ), some Iceland Scotland overflow water (ISOW) flows westward through gaps in the Reykjanes Ridge north of the CGFZ into the Irminger Sea, and some flows southward along the eastern flank of the Mid-Atlantic Ridge into the West European Basin. These results provide …
Characterization Of Subsurface Polycyclic Aromatic Hydrocarbons At The Deepwater Horizon Site, Arne Diercks, Raymond C. Highsmith, Vernon L. Asper, Dongjoo Joung, Zhengzhen Zhou, Laodong Guo, Alan M. Shiller, Andreas P. Teske, Norman Guinasso, Terry L. Wade, Steven E. Lohrenz
Characterization Of Subsurface Polycyclic Aromatic Hydrocarbons At The Deepwater Horizon Site, Arne Diercks, Raymond C. Highsmith, Vernon L. Asper, Dongjoo Joung, Zhengzhen Zhou, Laodong Guo, Alan M. Shiller, Andreas P. Teske, Norman Guinasso, Terry L. Wade, Steven E. Lohrenz
Faculty Publications
Here, we report the initial observations of distributions of polycyclic aromatic hydrocarbons (PAH) in subsurface waters near the Deepwater Horizon oil well site (also referred to as the Macondo, Mississippi Canyon Block 252 or MC252 well). Profiles of in situ fluorescence and beam attenuation conducted during 9-16 May 2010 were characterized by distinct peaks at depths greater than 1000 m, with highest intensities close to the wellhead and decreasing intensities with increasing distance from the wellhead. Gas chromatography/mass spectrometry (GC/MS) analyses of water samples coinciding with the deep fluorescence and beam attenuation anomalies confirmed the presence of polycyclic aromatic hydrocarbons …
Seasonal Variability In Air-Sea Fluxes Of Co2 In A River-Influenced Coastal Margin, Steven E. Lohrenz, Wei-Jun Cai, Fengwei Cai, Xiaogang Chen, Merritt Tuel
Seasonal Variability In Air-Sea Fluxes Of Co2 In A River-Influenced Coastal Margin, Steven E. Lohrenz, Wei-Jun Cai, Fengwei Cai, Xiaogang Chen, Merritt Tuel
Faculty Publications
Recent studies in the northern Gulf of Mexico and elsewhere have demonstrated that enhanced biological production in large river plumes may contribute to a net surface influx of atmospheric CO2. However, large rivers also deliver significant amounts of terrestrial carbon into continental margin waters; hence, the potential for large and variable signals in carbon flux exist in these regions. Here, we used a combination of satellite and ship-based observations to examine variability in surface pCO(2) and air-sea flux of carbon dioxide in relation to variations in river discharge and seasonal environmental conditions. Underway surface pCO(2) showed large seasonal differences based …
Wave Heights During Hurricane Katrina: An Evaluation Of Ppp And Ppk Measurements Of The Vertical Displacement Of The Gps Antenna, Stephan D. Howden, David Dodd, Leslie C. Bender Iii, Norman Guinasso, Josh Kohut
Wave Heights During Hurricane Katrina: An Evaluation Of Ppp And Ppk Measurements Of The Vertical Displacement Of The Gps Antenna, Stephan D. Howden, David Dodd, Leslie C. Bender Iii, Norman Guinasso, Josh Kohut
Faculty Publications
In August 2005 the eye of Hurricane Katrina passed 49 n mi to the west of a 3-m discus buoy operated by the Central Gulf of Mexico Ocean Observing System (CenGOOS). Buoy motions were measured with a strapped-down 6 degrees of freedom accelerometer, a three-axis magnetometer, and a survey-grade GPS receiver. The significant wave heights were computed from the buoy's accelerometer record and from the dual-frequency GPS measurements that were processed in two different ways. The first method was postprocessed kinematic (PPK) GPS, which requires another GPS receiver at a fixed known location, and the other was precise point positioning …
Beneath The Salt Marsh Canopy: Loss Of Soil Strength With Increasing Nutrient Loads, R. Eugene Turner
Beneath The Salt Marsh Canopy: Loss Of Soil Strength With Increasing Nutrient Loads, R. Eugene Turner
Faculty Publications
Although the broadly observed increase in nutrient loading rates to coastal waters in the last 100 years may increase aboveground biomass, it also tends to increase soil metabolism and lower root and rhizome biomass—responses that can compromise soil strength. Fourteen different multiyear field combinations of nutrient amendments to salt marshes were made to determine the relationship between soil strength and various nitrogen, phosphorus, and nitrogen+phosphorus loadings. There was a proportional decline in soil strength that reached 35% in the 60- to 100-cm soil layer at the highest loadings and did not level off. These loading rates are equivalent to those …
Reconstruction And Analysis Of The Chukchi Sea Circulation In 1990-1991, Gleb Panteleev, Dmitri A. Nechaev, Andrey Proshutinsky, R. Woodgate, J. Zhang
Reconstruction And Analysis Of The Chukchi Sea Circulation In 1990-1991, Gleb Panteleev, Dmitri A. Nechaev, Andrey Proshutinsky, R. Woodgate, J. Zhang
Faculty Publications
The Chukchi Sea (CS) circulation reconstructed for September 1990 to October 1991 from sea ice and ocean data is presented and analyzed. The core of the observational data used in this study comprises the records from 12 moorings deployed in 1990 and 1991 in U. S. and Russian waters and two hydrographic surveys conducted in the region in the fall of 1990 and 1991. The observations are processed by a two-step data assimilation procedure involving the Pan-Arctic Ice-Ocean Modeling and Assimilation System (employing a nudging algorithm for sea ice data assimilation) and the Semi-implicit Ocean Model [utilizing a conventional four-dimensional …
Abundance And Ecological Significance Of The Clam Rangia Cuneata (Sowerby, 1831) In The Upper Barataria Estuary (Louisiana, Usa), Wai Hing Wong, Nancy N. Rabalais, R. Eugene Turner
Abundance And Ecological Significance Of The Clam Rangia Cuneata (Sowerby, 1831) In The Upper Barataria Estuary (Louisiana, Usa), Wai Hing Wong, Nancy N. Rabalais, R. Eugene Turner
Faculty Publications
We proposed that Rangia cuneata (Sowerby, 1831) is an important estuarine bivalve with ecological significance in three coastal lakes in Barataria Bay, Gulf of Mexico—Lake Cataouatche, Lake Salvador and Lac des Allemands. Our goals were to determine the abundance and distribution of Rangia in these lakes and to measure clearance times to elucidate its potential impacts on phytoplankton communities. The estimated average densities of R. cuneata in Lake Cataouatche, Lake Salvador, and Lac des Allemands were 63, 157, and 107 individuals m−2, respectively, which is 30% lower than that observed in nearby Lake Pontchartrain. The size of clams in Lake …
A Comparison Of Methods For Determining Significant Wave Heights-Applied To A 3-M Discus Buoy During Hurricane Katrina, Leslie C. Bender Iii, Norman Guinasso, John N. Walpert, Stephan D. Howden
A Comparison Of Methods For Determining Significant Wave Heights-Applied To A 3-M Discus Buoy During Hurricane Katrina, Leslie C. Bender Iii, Norman Guinasso, John N. Walpert, Stephan D. Howden
Faculty Publications
In August 2005, the eye of Hurricane Katrina passed 90 km to the west of a 3-m discus buoy deployed in the Mississippi Sound and operated by the Central Gulf of Mexico Ocean Observing System (CenGOOS). The buoy motions were measured with a strapped-down, 6 degrees of freedom accelerometer, a three-axis magnetometer, and from the displacement of a GPS antenna measured by postprocessed-kinematic GPS. Recognizing that an accelerometer experiences a large offset due to gravity, the authors investigated four different means of computing wave heights. In the most widely used method for a buoy with a strapped-down, 1D accelerometer, wave …
A Lanthanide-Based Chemosensor For Bioavailable Fe3+ Using A Fluorescent Siderophore: An Assay Displacement Approach, Karen M. Orcutt, William Scott Jones, Andrea Mcdonald, David Schrock, Karl J. Wallace
A Lanthanide-Based Chemosensor For Bioavailable Fe3+ Using A Fluorescent Siderophore: An Assay Displacement Approach, Karen M. Orcutt, William Scott Jones, Andrea Mcdonald, David Schrock, Karl J. Wallace
Faculty Publications
The measurement of trace analytes in aqueous systems has become increasingly important for understanding ocean primary productivity. In oceanography, iron (Fe) is a key element in regulating ocean productivity, microplankton assemblages and has been identified as a causative element in the development of some harmful algal blooms. The chemosenor developed in this study is based on an indicator displacement approach that utilizes time-resolved fluorescence and fluorescence resonance energy transfer as the sensing mechanism to achieve detection of Fe3+ ions as low as 5 nM. This novel approach holds promise for the development of photoactive chemosensors for ocean deployment.
Construction, Figures Of Merit And Testing Of A Single-Cell Fluorescence Excitation Spectroscopy System, Laura S. Hill, Tammi L. Richardson, Louisa T.M. Profeta, Timothy J. Shaw, Christopher J. Hintz, Benjamin S. Twining, Evelyn Lawrenz, Micheal L. Myrick
Construction, Figures Of Merit And Testing Of A Single-Cell Fluorescence Excitation Spectroscopy System, Laura S. Hill, Tammi L. Richardson, Louisa T.M. Profeta, Timothy J. Shaw, Christopher J. Hintz, Benjamin S. Twining, Evelyn Lawrenz, Micheal L. Myrick
Faculty Publications
Characterization of phytoplankton community composition is critical to understanding the ecology and biogeochemistry of the oceans. One approach to taxonomic characterization takes advantage of differing pigmentation between algal taxa and thus differences in fluorescence excitation spectra. Analyses of bulk water samples, however, may be confounded by interference from chromophoric dissolved organic matter or suspended particulate matter. Here, we describe an instrument that uses a laser trap based on a Nikon TE2000-U microscope to position individual phytoplankton cells for confocal fluorescence excitation spectroscopy, thus avoiding interference from the surrounding medium. Quantitative measurements of optical power give data in the form of …