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Transports Of The Brazil And Malvinas Currents At Their Confluence, K. Maamaatuaiahutapu, V. Garçon, C. Provost, H. Mercier Jan 1998

Transports Of The Brazil And Malvinas Currents At Their Confluence, K. Maamaatuaiahutapu, V. Garçon, C. Provost, H. Mercier

Journal of Marine Research

Geostrophic transports of the western boundary currents at the Brazil/Malvinas Confluence in the South Atlantic Ocean are estimated from the data set of the Confluence 3 cruise (February 1990) with a nonlinear inverse model which takes into consideration density, current meter and wind data, and dynamical (planetary vorticity, Ekman, mass conservation) constraints. Inversions are carried out with two initial different levels of no motion at 1500 m (Case A) and at 3000 m (Case B). Consistencies of the water volume transports provided by both inversions are analyzed and compared to previous estimates. Current meter constraints are applied in the Malvinas …

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Assessing Organic Matter Mineralization, Degradability And Mixing Rate In An Ocean Margin Sediment (Northeast Atlantic) By Diagenetic Modeling, Karline Soetaert, Peter M. J. Herman, Jack J. Middelburg, Carlo Heip Jan 1998

Assessing Organic Matter Mineralization, Degradability And Mixing Rate In An Ocean Margin Sediment (Northeast Atlantic) By Diagenetic Modeling, Karline Soetaert, Peter M. J. Herman, Jack J. Middelburg, Carlo Heip

Journal of Marine Research

We test whether organic matter degradability, mixing activity, and total sediment mineralization can be estimated by inversion of a coupled nonlinear numerical steady-state diagenetic model. We use a single data set comprising oxygen, nitrate, ammonium and organic carbon versus depth profiles from a slope station in the Goban Spur area (1034 m, Northeast Atlantic). Based on an extensive sensitivity analysis, it appears that (1) when using all data, the total mineralization rates can be determined with reasonable precision; bioturbation and degradability are less well constrained and (2) total mineralization rates can be determined based on nitrate and oxygen profiles only; …

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Comments On ‘‘The Non-Wavelike Response Of A Continental Shelf To Wind’’ By G. T. Csanady, K. H. Brink, J. S. Allen Jan 1998

Comments On ‘‘The Non-Wavelike Response Of A Continental Shelf To Wind’’ By G. T. Csanady, K. H. Brink, J. S. Allen

Journal of Marine Research

Csanady (1998) presents solutions for time-dependent wind-driven flow in a barotropic coastal ocean. We disagree with two of his three boundary condition options and wish to clarify the origin of the non-wavelike aspect of the flow.

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The Effect Of A Cyclonic Eddy On The Distribution Of Lithogenic Particles In The Southern East China Sea, Shih-Chieh Hsu, Fei-Jan Lin, Woei-Lih Jeng, Tswen Yung Tang Jan 1998

The Effect Of A Cyclonic Eddy On The Distribution Of Lithogenic Particles In The Southern East China Sea, Shih-Chieh Hsu, Fei-Jan Lin, Woei-Lih Jeng, Tswen Yung Tang

Journal of Marine Research

Off northeastern Taiwan, the collision between the Kuroshio Current (KC) and the East China Sea (ECS) shelf forms a branch current (Kuroshio Branch Current) on the shelf, and the counterclockwise deflection of the subsurface Kuroshio water annually generates a cyclonic eddy, about 70 km in diameter, over the shelf-slope in summer. In this study, the total suspended matter collected from varying water depths over the eddy during August 1994 has been analyzed for Al, which is used as an indicator element to trace lithogenic particle transport. Simultaneously, the measurements of current field, using the Shipboard Acoustic Doppler Current Profiler, and …

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The Effect Of Biogenic Irrigation Intensity And Solute Exchange On Diagenetic Reaction Rates In Marine Sediments, Robert C. Aller, Josephine Y. Aller Jan 1998

The Effect Of Biogenic Irrigation Intensity And Solute Exchange On Diagenetic Reaction Rates In Marine Sediments, Robert C. Aller, Josephine Y. Aller

Journal of Marine Research

The activities of infaunal macrobenthos strongly influence the pathways, rates, and extent of organic matter remineralization and associated reactions in marine sediments. Solute transport during irrigation is a particularly important process that stimulates microbial activity and net remineralization, both within and adjacent to the bioturbated zone. Part of the stimulation proximal to the bioturbated zone is due to redox oscillation and oxidant supply during transport, but part of both the near and far-field effects are a result of other factors. Experiments designed to simulate different degrees of diffusive exchange, and thus infaunal abundances or activity, demonstrate a regular and strong …

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Diel Vertical Migration In Stratified Tidal Flows: Implications For Plankton Dispersal, A. E. Hill Jan 1998

Diel Vertical Migration In Stratified Tidal Flows: Implications For Plankton Dispersal, A. E. Hill

Journal of Marine Research

This paper examines the kinematics of the horizontal motion induced in marine plankton which undergo diel vertical migration (DVM) in oscillatory tidal currents with depth varying amplitude and phase. Particular attention is paid to the transport-producing effects of DVM in shallow, stratified seas where frictional decoupling associated with a reduction in the vertical eddy viscosity in the pycnocline can cause abrupt changes in tidal phase across the pycnocline. In M2-period tidal currents, horizontal displacements of up to 5 upper layer tidal excursions can be produced over a 15-day cycle and in S2-period currents, net unidirectional horizontal …

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Energetics Of Linear Geostrophic Adjustment In Stratified Rotating Fluids, Roger H. J. Grimshaw, Andrew J. Willmott, Peter D. Killworth Jan 1998

Energetics Of Linear Geostrophic Adjustment In Stratified Rotating Fluids, Roger H. J. Grimshaw, Andrew J. Willmott, Peter D. Killworth

Journal of Marine Research

The energy conversion ratio, γ, is shown to be bounded below by 0 and above by 1/2 in the two-dimensional linear geostrophic adjustment of a continuously stably stratified, incompressible, inviscid non-Boussinesq fluid. ''Two-dimensional'' refers to problems in which the initial isopycnal displacement field is an arbitrary function of the vertical (parallel to the rotation axis) and a single horizontal coordinate. By using Fourier analysis techniques, the paper also identified classes of initial isopycnal displacement profiles for which the adjustment process leads to γ > 1/3. Finally, an expression for γ is derived when the initial isopycnal displacement profile is three dimensional.

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Resource Use In The Trinational Sangha River Region Of Equatorial Africa: Histories, Knowledge Forms, And Institutions, Heather E. Eves, Rebecca Hardin, Stephanie Rupp Jan 1998

Resource Use In The Trinational Sangha River Region Of Equatorial Africa: Histories, Knowledge Forms, And Institutions, Heather E. Eves, Rebecca Hardin, Stephanie Rupp

Yale School of the Environment Bulletin Series

This volume is based on an international conference, “Natural Resource Use Relations in the Trinational Sangha River Region of the Northwest Congo Basin,” held at Yale University in September 1997. In recognition of the bilingual context in which conservation occurs in the three countries of the Sangha region — Cameroon, Central African Republic, and Congo — all sessions of the conference were conducted simultaneously in French and English. This publication, which is a complete rendering of the conference papers and discussion sessions, is available in its entirety in both French and English.

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Stratification And Circulation Produced By Heating And Evaporation On A Shelf, J. S. Turner Jan 1998

Stratification And Circulation Produced By Heating And Evaporation On A Shelf, J. S. Turner

Journal of Marine Research

A series of exploratory laboratory experiments has been carried out to model an 'inverse estuary,' in which density differences and outflows were generated by heating and evaporation on a shallow shelf. This shelf was connected to a deep, long region of uniform depth through a steep slope. The experimental tank was filled with homogeneous salt solution, and the shelf region heated with infrared lamps to produce temperature and salinity anomalies; fresh water was added at the far end of the tank to keep the depth (and the mean salinity) constant. The emphasis in these experiments was on the influence in …

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Natural Progression Of Aortic Stenosis In A Veteran Population, Marjory Alabre Jan 1998

Natural Progression Of Aortic Stenosis In A Veteran Population, Marjory Alabre

Yale Medicine Thesis Digital Library

No abstract provided.

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Income Inequality In Taiwan 1976-1995: Changing Family Composition, Aging, And Female Labor Force Participation, T. Paul Schultz Nov 1997

Income Inequality In Taiwan 1976-1995: Changing Family Composition, Aging, And Female Labor Force Participation, T. Paul Schultz

Discussion Papers

No abstract provided.

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Modulation Of The Rat Potassium Channel Kv1.5, Daniel Benjamin Saal Nov 1997

Modulation Of The Rat Potassium Channel Kv1.5, Daniel Benjamin Saal

Yale Medicine Thesis Digital Library

1. Kv1.5 is a delayed rectifier-type potassium channel. We have examined the localization of the channel protein using a polyclonal antibody against Kv1.5. This channel is expressed in numerous regions of the brain, primarily in glial cells. Its expression is particularly intense in the endfoot processes which abut the microvasculature of the brain. It is also expressed in the cell bodies and cellular processes in the pituitary.2. Immunoprecipitation of the Kv1.5 protein, from HEK 293 cells which were transformed with the Kv1.5 gene, revealed that the channel is phosphorylated and that treatment of cells with dibutyryl cyclic AMP (dibcAMP) or …

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Long-Run Structural And Productivity Change In U.S. Agriculture: Effects Of Prices And Policies, Robert E. Evenson, Wallace B. Huffman Jun 1997

Long-Run Structural And Productivity Change In U.S. Agriculture: Effects Of Prices And Policies, Robert E. Evenson, Wallace B. Huffman

Discussion Papers

No abstract provided.

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Yale Nurse, Yale School Of Nursing Apr 1997

Yale Nurse, Yale School Of Nursing

Yale School of Nursing Alumni Newsletters and Magazines

No abstract provided.

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Effects Of Tamoxifen On Prostaglandin E2 Induced Insulin-Like Growth Factor I Expression In Fetal Rat Osteoblasts, Kristina A. Crothers Jan 1997

Effects Of Tamoxifen On Prostaglandin E2 Induced Insulin-Like Growth Factor I Expression In Fetal Rat Osteoblasts, Kristina A. Crothers

Yale Medicine Thesis Digital Library

No abstract provided.

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The Steady Flow Between Reservoirs With Different Density And Level Through A Contraction, A. Odulo, J. C. Swanson, D. Mendelsohn Jan 1997

The Steady Flow Between Reservoirs With Different Density And Level Through A Contraction, A. Odulo, J. C. Swanson, D. Mendelsohn

Journal of Marine Research

This paper presents a complete analytical solution of steady gravity flow between two reservoirs connected by a channel of slowly varying breadth and containing fluids of different densities and levels. The hydrostatic approximation is used and dissipation is neglected. It is shown that seven different regimes are possible depending on the value of the parameter δ = γ/ε, which is the ratio of relative lighter and denser reservoir level difference, γ, to positive relative density difference, ε. The exact solution of the problem is obtained for all these regimes. If the level of the heavier fluid reservoir is higher than …

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Large-Scale Processes In The Upper Layers Of The Indian Ocean Inferred From Temperature Climatology, A. S. Unnikrishnan, S. Prasanna Kumar, G. S. Navelkar Jan 1997

Large-Scale Processes In The Upper Layers Of The Indian Ocean Inferred From Temperature Climatology, A. S. Unnikrishnan, S. Prasanna Kumar, G. S. Navelkar

Journal of Marine Research

Determination of amplitudes and phases for the annual and semi-annual cycle of the temperature in the Indian Ocean north of 20S from Levitus temperature climatology (1982) gives maximum amplitudes of the seasonal cycle at 100 m with the dominance of semi-annual cycle in the equatorial region and annual cycle elsewhere in the domain. The Bay of Bengal shows characteristics of the westward-propagating Rossby waves of annual period, while the Arabian Sea shows the dominance of Ekman pumping in the central region and westward-propagating features in the eastern region. Qualitative evidences obtained from the distribution of depth of 20°C isotherm and …

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Eigenanalysis Of The Two-Dimensional Wind-Driven Ocean Circulation Problem, V. A. Sheremet, G. R. Ierley, V. M. Kamenkovich Jan 1997

Eigenanalysis Of The Two-Dimensional Wind-Driven Ocean Circulation Problem, V. A. Sheremet, G. R. Ierley, V. M. Kamenkovich

Journal of Marine Research

A barotropic model of the wind-driven circulation in the subtropical region of the ocean is considered. A no-slip condition is specified at the coasts and slip at the fluid boundaries. Solutions are governed by two parameters: inertial boundary-layer width; and viscous boundary-layer width. Numerical computations indicate the existence of a wedge-shaped region in this two-dimensional parameter space, where three steady solutions coexist. The structure of the steady solution can be of three types: boundary-layer, recirculation and basin-filling-gyre. Compared to the case with slip conditions (Ierley and Sheremet, 1995) in the no-slip case the wedge-shaped region is displaced to higher Reynolds …

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Eddy Formation On A Continental Slope, Janet M. Becker, Rick Salmon Jan 1997

Eddy Formation On A Continental Slope, Janet M. Becker, Rick Salmon

Journal of Marine Research

We consider a uniform-density ocean in which the depth-independent horizontal velocity is driven by a two-gyre wind. Numerical solutions of the governing vorticity equation reveal that the solutions with a flat ocean bottom differ greatly from those in which a continental shelf and slope are present along the western boundary. In the ocean basin with a western continental shelf, steady inertial circulations readily lose stability to unsteady inertial circulations that spawn eddies. However, eddies do not form in the corresponding solutions for the flat-bottom ocean. Reducing the friction leads to flat-bottom solutions that shed eddies far offshore, but still differ …

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Mechanisms Of Infaunal Polychaete Dispersal And Colonization In An Intertidal Sandflat, David H. Shull Jan 1997

Mechanisms Of Infaunal Polychaete Dispersal And Colonization In An Intertidal Sandflat, David H. Shull

Journal of Marine Research

Changes in benthic infaunal population densities following disturbance may be influenced by colonization mechanisms. Accordingly, this study experimentally examined the relative importance of four colonization mechanisms for seven numerically dominant polychaete species in an intertidal estuarine sandflat in Connecticut, USA. The colonization mechanism an organism used depended upon species characteristics including larval developmental mode and depth distribution within the sediment. A spionid polychaete with planktonic larval development, Polydora cornuta, colonized experimental disturbance treatments primarily by larval settlement. A surface-dwelling syllid polychaete with nonplanktonic development, Streptosyllis arenae, colonized mainly by bedload transport. Two syllid polychaetes developmentally and morphologically similar …

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Analysis Of The Mean Annual Cycle Of The Dissolved Oxygen Anomaly In The World Ocean, Raymond G. Najjar, Ralph F. Keeling Jan 1997

Analysis Of The Mean Annual Cycle Of The Dissolved Oxygen Anomaly In The World Ocean, Raymond G. Najjar, Ralph F. Keeling

Journal of Marine Research

A global climatology of the dissolved oxygen anomaly (the excess over saturation) is created with monthly resolution in the upper 500 m of the ocean. The climatology is based on dissolved oxygen, temperature and salinity data archived at the National Oceanographic Data Center. Examination of this climatology reveals statistically significant annual cycles throughout the upper 500 m of the World Ocean, though seasonal variations are most coherent in the North Atlantic, where data density is greatest. Vertical trends in the phase and amplitude of the annual cycle are noted. The cycle in surface waters is characterized by a summer maximum …

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Phytoplankton Patches At Fronts: A Model Of Formation And Response To Wind Events, Peter J. S. Franks, Leonard J. Walstad Jan 1997

Phytoplankton Patches At Fronts: A Model Of Formation And Response To Wind Events, Peter J. S. Franks, Leonard J. Walstad

Journal of Marine Research

A subsurface patch of chlorophyll is a feature common to many fronts. The dynamics underlying the patch formation are not well understood; however, there appears to be a strong link between the biological and physical dynamics. Here we test the hypothesis that patch formation is a result of wind-forced motions of the front. Frontal responses to transient wind events include acceleration of the surface layers, changes in mixed-layer depth, and excitation of nonlinear oscillations at the front. Such dynamics can affect nutrient fluxes across the pycnocline and the coupling between trophic levels. To test this hypothesis, we developed a two-dimensional …

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Current Structure In The Rhine Region Of Freshwater Influence, A. J. Souza, J. H. Simpson, F. Schirmer Jan 1997

Current Structure In The Rhine Region Of Freshwater Influence, A. J. Souza, J. H. Simpson, F. Schirmer

Journal of Marine Research

Observation with HF radar, ADCPs and conventional current meters in the Rhine ROFI system in the North Sea indicate that the dominant currents are due to tidal flow, with important contributions from winds and density-driven circulation. The tidal currents are dominated by the semidiurnal components, principally the M2, with tidal ellipses parallel to the coast and a semimajor axis of the order of 1 m s−1 at the surface. The wind-driven flow varies between 1 and 3% of the wind speed and the rotation varies with depth in qualitative agreement with Ekman theory. After removal of the tidal and …

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Describing Additional Fluxes To Deep Sediment Traps And Water-Column Decay In A Coastal Environment, David A. Timothy, Stephen Pond Jan 1997

Describing Additional Fluxes To Deep Sediment Traps And Water-Column Decay In A Coastal Environment, David A. Timothy, Stephen Pond

Journal of Marine Research

Sediment traps were moored at three stations in Sechelt Inlet, a fjord in southern British Columbia, Canada, for five one-month deployment periods from late January to late June, 1991. On each mooring were traps at three depths; total and constituent fluxes often increased with depth. We present the flux data and describe an analytical model that is based on a set of simultaneous equations for which two unknowns are the decay rate of material representatively caught by two vertically-separated sediment traps and the composition of material causing observed increases in flux with depth. The unknowns are solved in a least-squares …

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Estimation Of Vertical Mixing In The Upper Ocean At Station P From Chlorofluorcarbons, R. J. Matear, C. S. Wong Jan 1997

Estimation Of Vertical Mixing In The Upper Ocean At Station P From Chlorofluorcarbons, R. J. Matear, C. S. Wong

Journal of Marine Research

Vertical mixing (Kv) in the upper ocean is estimated from chlorofluorocarbons (CFC's) F-11 and F-12 data collected on 5 cruises (1982, 1985, 1992, 1993, 1995) near Station P (50N, 145W). A one-dimensional advection-diffusion model was fitted to the data from each cruise to estimate vertical mixing (Kv) and upwelling velocity (w). With constant Kv and w, the average value of Kv and w was 0.4 ± 0.1 cm2 s−1 and 1.2 ± 0.4 m yr−1 respectively for the depth range 0–900 m below the base of …

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The Dynamics Of An Equivalent-Barotropic Model Of The Wind-Driven Circulation, Pavel S. Berloff, Stephen P. Meacham Jan 1997

The Dynamics Of An Equivalent-Barotropic Model Of The Wind-Driven Circulation, Pavel S. Berloff, Stephen P. Meacham

Journal of Marine Research

Various steady and time-dependent regimes of a quasi-geostrophic 1.5 layer model of an oceanic circulation driven by a steady wind stress are studied. After being discretized as a numerical model, the quasi-geostrophic equations of motion become a dynamical system with a large dimensional phase space. We find that, for a wide range of parameters, the large-time asymptotic regimes of the model correspond to low-dimensional attractors in this phase space. Motion on these attractors is significant in determining the intrinsic time scales of the system. In two sets of experiments, we explore the dependence of solutions on the viscosity coefficient and …

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Effect Of A Freshwater Pulse On Mesoscale Circulation And Phytoplankton Distribution In The Lower St. Lawrence Estuary, Claude Savenkoff, Alain F. Vézina, Yves Gratton Jan 1997

Effect Of A Freshwater Pulse On Mesoscale Circulation And Phytoplankton Distribution In The Lower St. Lawrence Estuary, Claude Savenkoff, Alain F. Vézina, Yves Gratton

Journal of Marine Research

As part of a multidisciplinary program to study the physical-biological interactions regulating carbon flows in the lower St. Lawrence Estuary (LSLE), three cruises were conducted in June–July 1990 during a neap-spring tidal cycle when biological production was expected to be maximal. Nutrient (nitrates and silicates), phytoplankton biomass (chlorophyll), oxygen, temperature, salinity, and current fields were used to elucidate the effect of a freshwater pulse produced by the discharge of the St. Lawrence and Saguenay rivers on the current fields and the biological variability and productivity of the LSLE. A simple Rossby adjustment model is presented to explain the temporal (3–5 …

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On The Eddy Transfer Of Tracers: Advective Or Diffusive?, Mei-Man Lee, David P. Marshall, Richard G. Williams Jan 1997

On The Eddy Transfer Of Tracers: Advective Or Diffusive?, Mei-Man Lee, David P. Marshall, Richard G. Williams

Journal of Marine Research

Geostrophic eddies have traditionally been viewed within oceanography as diffusing water masses and tracers in a down-gradient manner. However, eddies also have an advective role that may lead to an up-gradient transfer of tracers, as has been recognized in atmospheric tracer studies and recent eddy parameterizations developed for the ocean. Eddies provide an advective transfer or “bolus” velocity through the secondary circulation formed by the slumping of density surfaces in baroclinic instability. Here we use an eddy-resolving isopycnal ocean model to investigate the meridional transfer across a zonal jet. The jet undergoes baroclinic instability, forming a vibrant eddy field and …

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Rapid Subduction Of Organic Matter By Maldanid Polychaetes On The North Carolina Slope, L. Levin, N. Blair, D. Demaster, G. Plaia, W. Fornes, C. Martin, C. Thomas Jan 1997

Rapid Subduction Of Organic Matter By Maldanid Polychaetes On The North Carolina Slope, L. Levin, N. Blair, D. Demaster, G. Plaia, W. Fornes, C. Martin, C. Thomas

Journal of Marine Research

In situ tracer experiments conducted on the North Carolina continental slope reveal that tube-building worms (Polychaeta: Maldanidae) can, without ingestion, rapidly subduct freshly deposited, algal carbon (13C-labeled diatoms) and inorganic materials (slope sediment and glass beads) to depths of 10 cm or more in the sediment column. Transport over 1.5 days appears to be nonselective but spatially patchy, creating localized, deep hotspots. As a result of this transport, relatively fresh organic matter becomes available soon after deposition to deep-dwelling microbes and other infauna, and both aerobic and anaerobic processes may be enhanced. Comparison of tracer subduction with estimates …

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Solitary Rossby Waves With Baroclinic Modes, Z. Kizner Jan 1997

Solitary Rossby Waves With Baroclinic Modes, Z. Kizner

Journal of Marine Research

A class of exact solutions of the equation of conservation of the quasi-geostrophic vorticity in a continuously stratified ocean on the β-plane is studied. These are stationary solitary waves traveling east and having horizontal scale comparable with the Rossby deformation radius, which exist due to the balance between the nonlinearity and β-effect. The solutions look like a sum of a barotropic modon and a number of axially symmetric baroclinic components. The baroclinicity, represented in the form of vertical normal modes, introduces an extra “degree of freedom” into the problem (as compared with the barotropic model) and allows for the construction …

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