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Sensitivity Of Primary Production To Different Eddy Parameterizations: A Case Study Of The Spring Bloom Development In The Northwestern Mediterranean Sea, Marina Lévy, Martin Visbeck, Naomi Naik Jan 1999

Sensitivity Of Primary Production To Different Eddy Parameterizations: A Case Study Of The Spring Bloom Development In The Northwestern Mediterranean Sea, Marina Lévy, Martin Visbeck, Naomi Naik

Journal of Marine Research

The abilities of the Gent and McWilliams (1990) (GM) and Horizontal Diffusion (HD) eddyparameterizations to represent the mesoscale effects relevant for primary production are compared and analyzed. Following Lévy et al. (1999a), this is done in the case study of the spring bloom that follows the formation of a dense water patch in the northwestern Mediterranean Sea. It is shown that, unlike HD, the use of the GM parameterization can capture many aspects of the primary production enhancement associated with the restratifying action of mesoscale eddies. However, predicted primary production, when using the GM parameterization, is sensitive to the GM's …

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The Lattice Boltzmann Method As A Basis For Ocean Circulation Modeling, Rick Salmon Jan 1999

The Lattice Boltzmann Method As A Basis For Ocean Circulation Modeling, Rick Salmon

Journal of Marine Research

We construct a lattice Boltzmann model of a single-layer, "reduced gravity" ocean in a square basin, with shallow water or planetary geostrophic dynamics, and boundary conditions of no slip or no stress. When the volume of the moving upper layer is sufficiently small, the motionless lower layer outcrops over a broad area of the northern wind gyre, and the pattern of separated and isolated western boundary currents agrees with the theory of Veronis (1973). Because planetary geostrophic dynamics omit inertia, lattice Boltzmann solutions of the planetary geostrophic equations do not require a lattice with the high degree of symmetry needed …

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Sensitivity Of Ecosystem Parameters To Simulated Satellite Ocean Color Data Using A Coupled Physical-Biological Model Of The North Atlantic, Jim Gunson, Andreas Oschlies, Véronique Garçon Jan 1999

Sensitivity Of Ecosystem Parameters To Simulated Satellite Ocean Color Data Using A Coupled Physical-Biological Model Of The North Atlantic, Jim Gunson, Andreas Oschlies, Véronique Garçon

Journal of Marine Research

A means of assimilating simulated satellite ocean color data with a coupled physical-biological model of the North Atlantic Ocean is implemented, allowing the relative sensitivities of different biological parameters to those data to be investigated. The model consists of an eddy-permitting general circulation model derived from the WOCE Community Modeling Effort and a nitrogen-based, four-compartment NPZD marine ecosystem model. Many of the parameters in marine ecosystem models are poorly known and via assimilation, we hope to better constrain their values. The control parameters chosen for the variational assimilation are the model parameters involved in parameterizations of recycling as these are …

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Radiative Damping Of Near-Inertial Oscillations In The Mixed Layer, N. J. Blamforth, W. R. Young Jan 1999

Radiative Damping Of Near-Inertial Oscillations In The Mixed Layer, N. J. Blamforth, W. R. Young

Journal of Marine Research

An idealized model of the transmission of near-inertial waves from the mixed layer into the deeper ocean is studied in order to assess the combined effects of background geostrophic vorticity and the planetary vorticity gradient. The model geostrophic flow is steady and barotropic with a streamfunction ψ =-Ψ cos (2αy); the planetary vorticity gradient is modeled using the β-effect. After projection onto vertical modes, each modal amplitude satisfies a Schrödinger-like wave equation (in y and t) in which βy + (ψyy/2) plays the role of a potential. With realistic parameter values, this potential function …

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Wind-Driven Mixed Layer And Coastal Upwelling Processes Off The South Coast Of South Africa, Eckart H. Schumann Jan 1999

Wind-Driven Mixed Layer And Coastal Upwelling Processes Off The South Coast Of South Africa, Eckart H. Schumann

Journal of Marine Research

Most coastal mixed layer and upwelling investigations have concentrated on the more important fisheries regions situated on the west coasts of the continents, while this paper analyzes conditions on the zonally-orientated south coast of South Africa. Most of the data originate from a short measurement program in the southern summer of 1995, involving both CTD measurements from a small boat and data from a temperature array and coastal sea surface temperature (SST). Limited mixed layer statistics are derived and yield results similar to those of Lentz (1992), although a lack of current measurements precludes any assessment of the Ekman drift. …

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Spatial And Temporal Variability Of Turbulent Mixing In An Estuary, Hartmut Peters Jan 1999

Spatial And Temporal Variability Of Turbulent Mixing In An Estuary, Hartmut Peters

Journal of Marine Research

Observations with a microstructure/CTD profiler and an ADCP during five cruises in 1994/95 provide a glance at the turbulent mixing climate of a partially mixed estuary, the Hudson River. The cruises took place under widely varying conditions of river discharge and external forcing by water level fluctuations in New York Bight. Tidal and fortnightly variability patterns of stratification, shear and mixing characteristics were qualitatively repeatable, largely following the description of Peters (1997). (i) Longer-term variations of buoyancy frequency and Richardson number (Ri) during flood were weakly correlated with the river discharge. (ii) All flood tides had substantial mixing. …

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Interannual Variability In The Mesoscale Distribution Of The Depth Of The Upper Boundary Of The Oxygen Minimum Layer Off Northern Chile (18–24s): Implications For The Pelagic System And Biogeochemical Cycling, Carmen E. Morales, Samuel E. Hormazábal, José Luis Blanco Jan 1999

Interannual Variability In The Mesoscale Distribution Of The Depth Of The Upper Boundary Of The Oxygen Minimum Layer Off Northern Chile (18–24s): Implications For The Pelagic System And Biogeochemical Cycling, Carmen E. Morales, Samuel E. Hormazábal, José Luis Blanco

Journal of Marine Research

The low oxygen concentration (<2 ml L-1) at relatively shallow depths (<100 m) in the coastal upwelling zone and in the adjacent oceanic area is a distinct feature of the eastern boundary Humboldt Current System (HCS) off Peru and northern Chile; it affects the distribution of pelagic organisms and is associated with an important denitrification regime in the water column. Nevertheless, little information is available about the spatial and temporal variability in the distribution of the Oxygen Minimum Layer (OML) present in the HCS and the impact of its variability upon the pelagic system and biogeochemical cycles in the region. The present study reviews the oceanographic data obtained for the area off northern Chile (ca. 18 to 24S, out to 370 km), between 1980 and 1997, with the aim of characterizing the depth distribution of the upper boundary of the OML (1 ml L-1 iso-oxyline, representing also the oxycline) and investigating the association of its interannual variability with changes in coastal sea level and in the equatorial and local thermoclines. The depth of the upper boundary of the OML undergoes pronounced deepening during the occurrence of warm ENSO (El Niño Southern Oscillation) events over the whole area of study, and this, in turn, determines a condition of higher oxygen concentrations in the top 100 m layer. These changes follow closely the patterns of interannual variability in coastal sea level and depth …

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A Seasonal Succession Of Physical/Biological Interaction Mechanisms In The Sargasso Sea, J. D. Wiggert, T. C. Granata, T. D. Dickey, J. Marra Jan 1999

A Seasonal Succession Of Physical/Biological Interaction Mechanisms In The Sargasso Sea, J. D. Wiggert, T. C. Granata, T. D. Dickey, J. Marra

Journal of Marine Research

Six months of concurrent, co-located physical and bio-optical time series from a moored array deployed in the Sargasso Sea during 1987 have been analyzed by combining standard Fourier analysis techniques with a unique presentation method. The spectral information obtained from the time series analysis covers four orders of magnitude in frequency space. This is especially useful for revealing temporal variations in high frequency variance and the physical/biological interactions that occur at these frequencies. The presentation method used here consists of time/frequency distributions of normalized variance and squared coherence that resulted from the time series analysis. These reveal a seasonal succession …

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School Completion In Pakistan: Analysis Of Censoring And Selection Bias, Jessica Holmes Jan 1999

School Completion In Pakistan: Analysis Of Censoring And Selection Bias, Jessica Holmes

Discussion Papers

No abstract provided.

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Women’S Role In The Agricultural Household: Bargaining And Human Capital, T. Paul Schultz Jan 1999

Women’S Role In The Agricultural Household: Bargaining And Human Capital, T. Paul Schultz

Discussion Papers

No abstract provided.

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The Impact Of Medicaid Managed Care On The Lives Of The Chronically Mentally Ill In San Francisco, Deborah Paige Steinbaum Jan 1999

The Impact Of Medicaid Managed Care On The Lives Of The Chronically Mentally Ill In San Francisco, Deborah Paige Steinbaum

Yale Medicine Thesis Digital Library

No abstract provided.

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Commemoration Of Foreign Debt Extension, South Korea: Ministry Of Economy And Finance Jan 1999

Commemoration Of Foreign Debt Extension, South Korea: Ministry Of Economy And Finance

Documents

No abstract provided.

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Identifying The Autoantigen Of A Diabetogenic Cd8 T Cell Clone Isolated From Young Nod Mice, Caroline R. Dumont Jan 1999

Identifying The Autoantigen Of A Diabetogenic Cd8 T Cell Clone Isolated From Young Nod Mice, Caroline R. Dumont

Yale Medicine Thesis Digital Library

No abstract provided.

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Shifting Attitudes Toward Alcohol's Effect On The Fetus, Deena Berkowitz Jan 1999

Shifting Attitudes Toward Alcohol's Effect On The Fetus, Deena Berkowitz

Yale Medicine Thesis Digital Library

No abstract provided.

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Jamaica: Selected Issues, L.E. Escobar, A. Hilaire, I. Lukonga, P. Rado, A. Schipke Jan 1999

Jamaica: Selected Issues, L.E. Escobar, A. Hilaire, I. Lukonga, P. Rado, A. Schipke

Documents

No abstract provided.

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Characterization Of Components Of The Toll/Nf-Kb Signal Transduction Pathway : Implications For Host Defense, Jesse A. Flaxenburg Jan 1999

Characterization Of Components Of The Toll/Nf-Kb Signal Transduction Pathway : Implications For Host Defense, Jesse A. Flaxenburg

Yale Medicine Thesis Digital Library

No abstract provided.

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Nuclear Magnetic Resonance Studies Of Free Fatty Acid Induced Insulin Resistance In Vivo, Dennis Lee Jan 1999

Nuclear Magnetic Resonance Studies Of Free Fatty Acid Induced Insulin Resistance In Vivo, Dennis Lee

Yale Medicine Thesis Digital Library

No abstract provided.

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Stimulation Of Myocardial Amp-Activated Protein Kinase By Aicar Increases Cardiac Glucose Uptake And Causes Glut4 And Glut1 Translocation In Vivo, Senai Asefaw Jan 1999

Stimulation Of Myocardial Amp-Activated Protein Kinase By Aicar Increases Cardiac Glucose Uptake And Causes Glut4 And Glut1 Translocation In Vivo, Senai Asefaw

Yale Medicine Thesis Digital Library

No abstract provided.

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On The Seasonal Nitrogen Dynamics Of The Baltic Proper Biogeochemical Reactor, Kari Eilola, Anders Stigebrandt Jan 1999

On The Seasonal Nitrogen Dynamics Of The Baltic Proper Biogeochemical Reactor, Kari Eilola, Anders Stigebrandt

Journal of Marine Research

During the last decade it has become increasingly obvious that the turnover of dissolved organic nitrogen DON in marine environments is quite vigorous. This paper quantifies the turnover of DON in the Baltic proper regarded as a biogeochemical reactor. In a nitrogen model for the reactor, dissolved inorganic nitrogen DIN, DON and molecular N, fixed by cyanobacteria, can be used for plant production. The decomposition of particulate organic matter is assumed to produce DON and DIN as end products in the proportions (1- η) to η (0 ≤ η ≤ 1). The model includes two internal sink processes, denitrification and …

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On The Influence Of The Parameterization Of Lateral Boundary Layers On The Thermohaline Circulation In Coarse-Resolution Ocean Models, Thierry Huck, Andrew J. Weaver, Alain Colin De Verdière Jan 1999

On The Influence Of The Parameterization Of Lateral Boundary Layers On The Thermohaline Circulation In Coarse-Resolution Ocean Models, Thierry Huck, Andrew J. Weaver, Alain Colin De Verdière

Journal of Marine Research

Because of the first order geostrophic balance in the ocean interior, the parameterization of lateral boundary layers has more influence than the parameterization of viscosity on the thermohaline overturning and the deep water properties in coarse-resolution ocean circulation models. Different formulations of momentum dissipation and associated boundary conditions are implemented within a planetary-geostrophic ocean circulation model for a Cartesian coordinate, flat-bottomed, β-plane, with restoring boundary conditions for the surface density and zero wind stress. Traditional Laplacian friction with a no-slip boundary condition produces an interior circulation in good agreement with geostrophy and the Sverdrup balance, but generates very large vertical …

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Enhanced Degradation Of Algal Lipids By Benthic Macrofaunal Activity: Effect Of Yoldia Limatula, Ming-Yi Sun, Robert C. Aller, Cindy Lee, Stuart G. Wakeham Jan 1999

Enhanced Degradation Of Algal Lipids By Benthic Macrofaunal Activity: Effect Of Yoldia Limatula, Ming-Yi Sun, Robert C. Aller, Cindy Lee, Stuart G. Wakeham

Journal of Marine Research

We used the protobranch bivalve, Yoldia limatula, in a series of incubation experiments to test whether activities of deposit-feeding macrofauna cause differences in lipid degradation processes relative to controls lacking macrofauna. Uniformly 13C-labeled algae (13C > 98%) were used as a source of fresh planktonic lipids, easily distinguished from bulk sedimentary lipids by GC/MS. Variations in concentration of major lipid components ([16:1(ω7), 16:0 and 18:1(ω9)] fatty acids and phytol) were followed as a function of time in incubations with and without Yoldia. Results showed that Yoldia can significantly enhance the degradation of planktonic lipids in sediments. …

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Salt Fingers In Three Dimensions, Timour Radko, Melvin E. Stern Jan 1999

Salt Fingers In Three Dimensions, Timour Radko, Melvin E. Stern

Journal of Marine Research

Three dimensional (3D) numerical calculations are made for a vertically unbounded fluid with initially uniform vertical gradients of sugar ( S ) and salt ( T ), where τ = κS/κT = 1/3 is the diffusivity ratio, and the molecular viscosity is ν >> κT. The latter inequality allows us to neglect the nonlinear term in the momentum equation, while retaining such terms in the T-S equations. The discrete 3D Fourier spectrum resolves the fastest growing horizontal wavelength, as well as the depth independent Fourier component. Unlike previous calculations for the pure 2D case the finite …

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Near-Surface Circulation And Kinetic Energy In The Tropical Indian Ocean Derived From Lagrangian Drifters, S. S. C. Shenoi, P. K. Saji, A. M. Almeida Jan 1999

Near-Surface Circulation And Kinetic Energy In The Tropical Indian Ocean Derived From Lagrangian Drifters, S. S. C. Shenoi, P. K. Saji, A. M. Almeida

Journal of Marine Research

Trajectories of 412 satellite-tracked drifting buoys deployed in the tropical Indian Ocean have been analyzed to document the surface circulation and kinetic energy field. Only drifters drogued at 15 m depth and having drag area ratio greater than 35 are used to estimate current velocities. Unlike in earlier studies, the widening of the Equatorial Jet in the eastern equatorial Indian Ocean and the westward flow at the equator during July–August are apparent in the present data set. The comparison of drifter data with the seasonal mean dynamic topography (0/1000 db) shows that the surface circulation pattern inferred from dynamic topography …

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Bering Sea Deep Circulation: Water Properties And Geopotential, Ronald K. Reed, Calvin W. Mordy Jan 1999

Bering Sea Deep Circulation: Water Properties And Geopotential, Ronald K. Reed, Calvin W. Mordy

Journal of Marine Research

Deep temperature and silicate data from the Bering Sea demonstrate patterns that are consistent and allow inference of near-bottom circulation. The cold source water enters Kamchatka Strait and mainly moves toward the southeast through a narrow topographic gap and into Bowers Basin. There is also a narrow, coherent flow eastward, and eventually southeastward, near the steep flank of Bowers Ridge. At levels ~100–300 m above the bottom, there is a suggestion of upward motion near the margins of much of the deep Bering Sea. Near-bottom geopotential gradients, referred to 3000 db, are in agreement with flow inferred from water properties.

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Experiments On Waves Trapped Over The Continental Slope And Shelf In A Continuously Stratified Rotating Ocean, And Their Incidence On A Canyon, Daniel L. Codiga, Dominique P. Renouard, Adam M. Fincham Jan 1999

Experiments On Waves Trapped Over The Continental Slope And Shelf In A Continuously Stratified Rotating Ocean, And Their Incidence On A Canyon, Daniel L. Codiga, Dominique P. Renouard, Adam M. Fincham

Journal of Marine Research

Continental margins form a waveguide for topographic Rossby waves, which can be trapped to the bottom by continuous stratification and concentrated over the continental slope while propagating along the coast. We present results of laboratory wave simulations designed to keep as many dimensionless numbers (Rossby, Burger, normalized frequency, wave steepness, geometrical, Ekman, and Reynolds) as possible similar to those of coastal-trapped waves, such as are observed in coastal regions around the world. The 13-m diameter rotating tank is salt-stratified and a continental slope joins a shallow shelf region along the outer tank circumference to a deep central region. The velocity …

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Enzymatically Hydrolyzable Amino Acids In North Sea Sediments And Their Possible Implication For Sediment Nutritional Values, B. Dauwe, J. J. Middelburg, P. Van Rijswijk, J. Sinke, P. M. J. Herman, C. H. R. Heip Jan 1999

Enzymatically Hydrolyzable Amino Acids In North Sea Sediments And Their Possible Implication For Sediment Nutritional Values, B. Dauwe, J. J. Middelburg, P. Van Rijswijk, J. Sinke, P. M. J. Herman, C. H. R. Heip

Journal of Marine Research

The nutritional value of peptidic material in five North Sea sediments that differ in organic matter quality has been investigated with an enzymatic approach measuring the digestibility (rate constant k of proteolysis by protease) and the proportion of bioavailable fraction of amino acids (%EHAA-i:THAA). The bioavailable fraction in sediments varied between 14-50% EHAA-i:THAA and was generally lower than in potential source organisms such as algae (40-43%), plankton (~80%) and bacteria (57-72%). The rate of proteolysis of the amino acids varied among stations (k = 0.3-3.1 h-1) with a systematic decrease when going from labile to more refractory …

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Spatial Variation Of Total Co2 And Total Alkalinity In The Northern Indian Ocean: A Novel Approach For The Quantification Of Anthropogenic Co2 In Seawater, C. Goyet, C. Coatanoan, G. Eischeid, T. Amaoka, K. Okuda, R. Healy, S. Tsunogai Jan 1999

Spatial Variation Of Total Co2 And Total Alkalinity In The Northern Indian Ocean: A Novel Approach For The Quantification Of Anthropogenic Co2 In Seawater, C. Goyet, C. Coatanoan, G. Eischeid, T. Amaoka, K. Okuda, R. Healy, S. Tsunogai

Journal of Marine Research

As part of a cooperative effort of the Joint Global Ocean Flux Study (JGOFS) and of the World Ocean Circulation Experiment (WOCE) program, we have measured total CO2 (TCO2) and total alkalinity (TA) along three sections in the northern Indian Ocean. One section through the Gulf of Aden to the Arabian Sea is parallel to the coast of Yemen. One section is across the Arabian Sea along the nominal 9N latitude and the other section is across the Bay of Bengal along the nominal 10N latitude. The measurements were performed on board R/V Knorr in September-October 1995. …

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Some Historical, Theoretical And Applied Aspects Of Quantitative Water Mass Analysis, Matthias Tomczak Jan 1999

Some Historical, Theoretical And Applied Aspects Of Quantitative Water Mass Analysis, Matthias Tomczak

Journal of Marine Research

The concept of water masses is reviewed from the point of view of quantitative water mass analysis. A theoretical framework is presented which describes the life history of water masses in terms of formation, consolidation, aging and decay. Water masses are described as physical entities and compared with their atmospheric counterparts (air masses). The classical temperature-salinity diagram is expanded into the mathematical concept of water types in an n-dimensional parameter space. Water types and their standard deviations are introduced as the foundation for quantitative water mass analysis. The relationship between parameter space and physical space is established through the …

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Modeling The Antarctic Circumpolar Current: A Comparison Of Fram And Equivalent Barotropic Model Results, V. O. Ivchenko, A. E. Krupitsky, V. M. Kamenkovich, N. C. Wells Jan 1999

Modeling The Antarctic Circumpolar Current: A Comparison Of Fram And Equivalent Barotropic Model Results, V. O. Ivchenko, A. E. Krupitsky, V. M. Kamenkovich, N. C. Wells

Journal of Marine Research

Analyzing the FRAM simulations, Killworth (1992) noticed a strong tendency for self-similarity in the vertical structure of the velocity field of the Antarctic Circumpolar Current (ACC). By assuming the self-similarity as a hypothesis, Krupitsky et al. (1996) developed an equivalent barotropic (EB) model of the ACC capable of describing the horizontal structure of the ACC. Compared to the multi-level-primitive-equation GCM, the EB model appeared substantially simpler and therefore useful in pilot process-oriented and sensitivity studies. In the present study dynamical and kinematical comparisons of the EB and FRAM outputs are given.

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Formation And Circulation Of The Water Masses Between The Southern Indian Ocean And Antarctica: Results From Δ18o, Michael P. Meredith, Karen J. Heywood, Russell D. Frew, Paul F. Dennis Jan 1999

Formation And Circulation Of The Water Masses Between The Southern Indian Ocean And Antarctica: Results From Δ18o, Michael P. Meredith, Karen J. Heywood, Russell D. Frew, Paul F. Dennis

Journal of Marine Research

We present measurements of the stable isotopes of oxygen (18O and 16O) from seawater samples collected during the Antarctic Deep Outflow Experiment (ADOX) cruises in the Southern Ocean and southern Indian Ocean, February to March, 1993 and 1994. The data are used in conjunction with hydrographic data to infer characteristics of the formation and circulation of water masses found in the region. The waters on the continental shelf of Antarctica (adjacent to the Princess Elizabeth Trough; PET) are isotopically the lightest found due to the injection of about 1% of glacial meltwater, and are probably advected to …

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