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Measurements Of Internal Wave Band Eddy Fluxes Above A Sloping Bottom, Hans Van Haren, Neil Oakey, Chris Garrett Jan 1994

Measurements Of Internal Wave Band Eddy Fluxes Above A Sloping Bottom, Hans Van Haren, Neil Oakey, Chris Garrett

Journal of Marine Research

The boundary layer near a sloping bottom may have a major influence on the ocean's interior density structure (due to “boundary mixing”) and on its circulation (because of the arrest of the Ekman layer by buoyancy forces). As a first attempt to measure eddy fluxes of momentum and buoyancy, in order to quantify the mixing in this region, we have carried out a 5-day pilot experiment on a sloping side of Emerald Basin on the Scotian Shelf. A moored upward-looking 1.2 MHz ADCP and a thermistor chain mounted along its vertical axis returned analyzable data between 8 and 17 m …

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Set-Down Computations Over An Arbitrarily Inclined Plane Bed, Ulf Torsten Ehrenmark Jan 1994

Set-Down Computations Over An Arbitrarily Inclined Plane Bed, Ulf Torsten Ehrenmark

Journal of Marine Research

A perturbation theory, for waves on a perfect fluid in a wedge-shaped domain, is used to derive integral expressions for set-down valid up to the breaker line for arbitrary wedge angles α. Computations are carried out for a set α = π/2N, (N = 2,3,…,7,15) using a generalized Simpson quadrature and these confirm that existing theory underestimates the set-down by a factor which increases with the wedge angle. Curve fitting techniques are used to deduce a modification of the formula given by Longuet-Higgins and Stewart (1963) which can be universally implemented to estimate set-down just seaward of …

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A Modelling Study Of Discontinuous Biological Irrigation, Bernard P. Boudreau, Roberta L. Marinelli Jan 1994

A Modelling Study Of Discontinuous Biological Irrigation, Bernard P. Boudreau, Roberta L. Marinelli

Journal of Marine Research

Irrigation of infaunal dwellings can lead to significant alteration of solute distributions in sediments. As a result, sediment-seawater fluxes of nutrients and dissolved carbon are greatly enhanced, and the biology of benthic communities is affected. The most realistic mathematical representation of irrigation and its effect on sediment geochemistry is Aller's (1980) cylinder model. One critical assumption of this model is that burrows are irrigated continually, and that burrow water solute concentrations are identical to overlying water concentrations at all times. However, the vast majority of infaunal tube- and burrow-dwelling organisms irrigate periodically, i.e. in an on/off cycle. During periodic irrigation, …

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Instability Waves In The Gulf Stream Front And Its Thermocline Layer, Sang-Ki Lee, G. T. Csanady Jan 1994

Instability Waves In The Gulf Stream Front And Its Thermocline Layer, Sang-Ki Lee, G. T. Csanady

Journal of Marine Research

We carried out linear instability calculations on a three layer Gulf Stream front model in an attempt to elucidate the interaction of the thermocline layer with surface slopewater shoreward of the front. The basic state is geostrophic balance and constant potential vorticity in the two active layers, but the perturbations are ageostrophic. We found the flow to be unstable to long wave perturbations, the wavelength of the most unstable wave to be of the order of 10 radii of deformation. The instability is mainly baroclinic, 75–85% of the energy supply to the growing perturbation coming from basic flow potential energy. …

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On Topographic Pressure Drag In A Zonal Channel, Alexander Krupitsky, Mark A. Cane Jan 1994

On Topographic Pressure Drag In A Zonal Channel, Alexander Krupitsky, Mark A. Cane

Journal of Marine Research

The effect of bottom topography H on the barotropic transport in a periodic zonal channel is studied. An asymptotic approximation is found for the zonal transport on an f-plane and a β-plane when all f/H isolines are blocked by the zonal walls. It is shown that to leading order, the zonal channel transport is independent of friction. In this it is similar to the Sverdrup transport in a basin. To leading order, the transport is proportional to the bottom topographic wavelength, and inversely proportional to the height of the topography and to R, the range of values of …

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Lateral Entrainment In Baroclinic Currents, Melvin E. Stern, Jean-Raymond Bidlot Jan 1994

Lateral Entrainment In Baroclinic Currents, Melvin E. Stern, Jean-Raymond Bidlot

Journal of Marine Research

A two layer shear flow model with piecewise uniform potential vorticity is used to show that circulation or free exchange of parcels in an isopycnal layer of uniform potential vorticity can be greatly inhibited by a strong potential vorticity front in another isopycnal layer. On the other hand, a net mass transfer across the edge of a shear flow can be produced by the initial presence of a strong mesoscale eddy. The entrainment resulting from this eddy-shear flow interaction is defined and quantified for an ensemble of initial realizations. It is suggested that dynamically similar entrainment processes, occurring in more …

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Water-Mass Distributions In The Western South Atlantic; A Section From South Georgia Island (54s) Northward Across The Equator, Mizuki Tsuchiya, Lynne D. Talley, 0 S. Mccartney Jan 1994

Water-Mass Distributions In The Western South Atlantic; A Section From South Georgia Island (54s) Northward Across The Equator, Mizuki Tsuchiya, Lynne D. Talley, 0 S. Mccartney

Journal of Marine Research

A long CTD/hydrographic section with closely spaced stations was made in February–April 1989 in the western Atlantic Ocean between 0°40′N and South Georgia (54S) along a nominal longitude of 25W. Vertical sections of various properties from CTD and discrete water-sample measurements are presented and discussed in terms of the large-scale circulation of the South Atlantic Ocean. One of the most important results is the identification of various deep-reaching fronts in relation to the large-scale circulation and the distribution of mode waters. Five major fronts are clearly defined in the thermal and salinity fields. These are the Polar (49.5S), Subantarctic (45S), …

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Macrofaunal Response To Artificial Enrichments And Depressions In A Deep-Sea Habitat, P. V. R. Snelgrove, J. F. Grassle, R. F. Petrecca Jan 1994

Macrofaunal Response To Artificial Enrichments And Depressions In A Deep-Sea Habitat, P. V. R. Snelgrove, J. F. Grassle, R. F. Petrecca

Journal of Marine Research

To test whether colonizing macrofauna specialize on different types of small-scale patches of food and disturbance in the deep sea, sediment tray and artificial depression colonization experiments were conducted on the deep-sea floor at 900-m depth, south of St. Croix, U.S. Virgin Islands. Trays and depressions were unenriched (Unenriched Controls) or enriched with either Thalassiosira sp. or Sargassum sp. Concurrent deployment of different types of enrichment and disturbance made it possible to evaluate whether macrofauna specialize on different patches, and thus avoid species interactions that might lead to competitive exclusion. Depressions create a hydrodynamic regime that traps passive particles, allowing …

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Disturbance Associated With Bait-Collection For Sandprawns (Callianassa Kraussi) And Mudprawns (Upogebia Africana): Long-Term Effects On The Biota Of Intertidal Sandflats, Rachel P. Wynberg, George M. Branch Jan 1994

Disturbance Associated With Bait-Collection For Sandprawns (Callianassa Kraussi) And Mudprawns (Upogebia Africana): Long-Term Effects On The Biota Of Intertidal Sandflats, Rachel P. Wynberg, George M. Branch

Journal of Marine Research

The sandprawn Callianassa kraussi and the mudprawn Upogebia africana are used extensively as fish bait in southern Africa. A holistic analysis of disturbance associated with experimental prawn-collecting was undertaken to determine its repercussions upon the sediment and associated macrofaunal, meiofaunal, microbial and microalgal communities. Patterns of recovery were examined for 18 months following the disturbance. The recovery of both C. kraussi and U. africana was far more protracted than predicted, taking 18 months for completion. Sedimentary compaction, associated with the removal of prawns, could account for these prolonged recoveries. Both C. kraussi and U. africana suffered greater depressions of population …

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Circulation, Transport And Bottom Boundary Layers Of The Deep Currents In The Brazil Basin, X. Durrieu De Madron, G. Weatherly Jan 1994

Circulation, Transport And Bottom Boundary Layers Of The Deep Currents In The Brazil Basin, X. Durrieu De Madron, G. Weatherly

Journal of Marine Research

Zonal and meridional hydrographic sections obtained for the South Atlantic Ventilation Experiment are used to study the circulation patterns and estimate the transports of North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW) in the Brazil Basin. The NADW Deep Western Boundary Current (DWBC) appears to be a relatively large (≈ 800 km wide by 2 km thick), double core current, separated by counterflowing recirculation. It appears to split, branching seaward at the Cape Saõ Roque near 5S and again at the Columbia-Trinidad Seamount Chain at 21S. As a result of this latter bifurcation, the NADW DWBC flow in …

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Wave-Induced Abyssal Recirculations, Michael A. Spall Jan 1994

Wave-Induced Abyssal Recirculations, Michael A. Spall

Journal of Marine Research

The forcing of abyssal recirculation gyres by cross-isopycnal mixing and wave fluxes near the deep western boundary is investigated. A three-layer isopycnal primitive equation model is applied in a series of experiments to an idealized basin with bottom topography. In the absence of deep western boundary current instabilities, cross-isopycnal mixing forces a cyclonic recirculation gyre, modified by topography, which is consistent with the traditional Stommel-Arons model. Instabilities of the boundary current fundamentally alter the mean basin-scale deep flow from a cyclonic recirculation to an anticyclonic recirculation. Bottom topography plays a key role in destabilizing the mean flow. The forcing mechanism …

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Effects Of Porewater Hydrogen Sulfide On The Feeding Activity Of The Subsurface Deposit-Feeding Polychaete, Clymenella Torquata, Leidy, Charlotte M. Fuller Jan 1994

Effects Of Porewater Hydrogen Sulfide On The Feeding Activity Of The Subsurface Deposit-Feeding Polychaete, Clymenella Torquata, Leidy, Charlotte M. Fuller

Journal of Marine Research

The effects of porewater hydrogen sulfide concentrations on the feeding and tube-building activity of the subsurface, deposit-feeding polychaete, Clymenella torquata were experimentally determined in the laboratory. Porewater hydrogen sulfide concentrations were manipulated by injecting a buffered, isotonic sodium sulfide solution into the experimental chambers. Fecal material was collected and weighed and tube-building activity was monitored daily. Fecal production was negatively correlated with porewater hydrogen sulfide concentration during experiments conducted in June and July. Hydrogen sulfide concentrations greater than 1000 μM in June and 700 μM in July resulted in reduced fecal production. Fecal production was not correlated with porewater hydrogen …

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Particle Bioturbation In Massachusetts Bay: Preliminary Results Using A New Deliberate Tracer Technique, Robert A. Wheatcroft, Ilhan Olmez, Francais X. Pink Jan 1994

Particle Bioturbation In Massachusetts Bay: Preliminary Results Using A New Deliberate Tracer Technique, Robert A. Wheatcroft, Ilhan Olmez, Francais X. Pink

Journal of Marine Research

To better understand temporal and particle size-dependent bioturbation processes, we conducted a study of sediment mixing in Massachusetts Bay using a newly developed deliberate tracer technique. Sediments from a 32-m, fine-grained site were collected and the 38–62 (“silt”) and 63–125 (“sand”) μm fractions isolated. These particle-size fractions were labeled with two different noble metals (Au: silt & Ag: sand) using a thermal diffusion technique. Mixtures of the tracers were spread onto the seafloor in April and July 1992 by divers and were tube-cored (3 replicates) ˜ 80 d later in each case. Vertical profiles of the tracers were measured at …

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A Linear Homogeneous Model For Topographic Control Of The Antarctic Circumpolar Current, Liping Wang Jan 1994

A Linear Homogeneous Model For Topographic Control Of The Antarctic Circumpolar Current, Liping Wang

Journal of Marine Research

The results from the homogeneous channel model discussed by Wang and Huang (1994) is extended to a model whose geometry consists of a zonal channel and two partial meridional barriers along each boundary at the same longitude. Both the model transport and especially the model circulation are significantly affected by the presence of the two meridional barriers. There is a critical height of the ridge between the two partial meridional barriers, above which all geostrophic contours in the channel are blocked. In the case with a subcritically high ridge, the Sverdrup balance does not apply and there is no finite …

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The North Atlantic Circulation: Combining Simplified Dynamics With Hydrographic Data, Philip S. Bogden, Russ E. Davis, Rick Salmon Jan 1993

The North Atlantic Circulation: Combining Simplified Dynamics With Hydrographic Data, Philip S. Bogden, Russ E. Davis, Rick Salmon

Journal of Marine Research

We estimate the time-averaged velocity field in the North Atlantic from observations of density, wind stress and bottom topography. The flow is assumed geostrophic, with prescribed Ekman pumping at the surface, and no normal component at the bottom. These data and dynamics determine velocity to within an arbitrary function of (Coriolis parameter)/(ocean depth), which we call the “dynamical free mode.” The free mode is selected to minimize mixing of potential density at mid-depth. This tracer-conservation criterion serves as a relatively weak constraint on the calculation. Estimates of vertical velocity are particularly sensitive to variations in the free mode and to …

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Rates And Possible Mechanism Of Light-Dependent Degradation Of Pigments In Detritus Derived From Phytoplankton, James R. Nelson Jan 1993

Rates And Possible Mechanism Of Light-Dependent Degradation Of Pigments In Detritus Derived From Phytoplankton, James R. Nelson

Journal of Marine Research

Rates of degradation of phytoplankton chlorophylls and carotenoids under visible light exposure were determined in laboratory experiments. Killed phytoplankton cells and copepod fecal pellets were used as sources of pigments. Chlorophylls, pheopigments and carotenoids were analyzed by HPLC. Experiments included aerated and N2 bubbled treatments (light and dark), and in one experiment, killed phytoplankton cells were aged in darkness for 5 days in the presence of an active bacterial population prior to exposure to light. Pigment bleaching in solution was also examined. Pigment degradation was light- and oxygen-dependent and showed apparent first-order kinetics with respect to light exposure. The …

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The Annual Variation Of Water Mass Structure In The Gulf Of Maine: 1986-1987, W. S. Brown, J. D. Irish Jan 1993

The Annual Variation Of Water Mass Structure In The Gulf Of Maine: 1986-1987, W. S. Brown, J. D. Irish

Journal of Marine Research

The annual variation in the structure and disposition of the principal water masses in the Gulf of Maine has been investigated with a set of water property observations using five shipboard surveys and four moored arrays with data telemetry. The time series observations document the cooling-induced destratification of the upper water column during autumn and the subsequent mixed-layer deepening in the western Gulf—primarily in Wilkinson Basin— during winter 1987. Unusually large amounts of fresher Scotian Shelf Water inflow inhibited winter 1987 vertical mixing in the eastern Gulf relative to the deep mixing in and around Wilkinson Basin in the western …

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The Importance Of The Scotia Sea On The Outflow Of Weddell Sea Deep Water, Ricardo A. Locarnini, Thomas Whitworth Iii, Worth D. Nowlin Jr. Jan 1993

The Importance Of The Scotia Sea On The Outflow Of Weddell Sea Deep Water, Ricardo A. Locarnini, Thomas Whitworth Iii, Worth D. Nowlin Jr.

Journal of Marine Research

Weddell Sea Deep Water influences the thermohaline circulation of the world ocean directly as a component of the deep western boundary current in the South Atlantic Ocean and indirectly by cooling and freshening Circumpolar Deep Water. Because it is filled with recently ventilated Weddell Sea Deep Water, the Scotia Sea is important to both influences. The main component of the abyssal waters renewing most of the world oceans via deep boundary currents is the Circumpolar Deep Water of the Antarctic Circumpolar Current. Weddell Sea Deep Water is recognized as the main source of cold, fresh waters to Circumpolar Deep Water, …

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On The Role Of Large Bubbles In Air-Sea Gas Exchange And Supersaturation In The Ocean, Ralph F. Keeling Jan 1993

On The Role Of Large Bubbles In Air-Sea Gas Exchange And Supersaturation In The Ocean, Ralph F. Keeling

Journal of Marine Research

A parameterization of bubble-induced gas exchange is presented in which the bubble contribution to gas exchange is expressed in terms of separate transfer velocities for ingassing (Kbin) and outgassing (Kbout). The difference between the ingassing and outgassing velocities (Kbin − Kbout) is further separated into two components, the first caused by the injection of small bubbles into the water, the second caused by gas exchange across the surface of hydrostatically compressed larger bubbles. It is argued that both Kbout and the exchange contribution to …

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The Ecology Of Larger Microzooplankton In The Weddell-Scotia Confluence Area: Horizontal And Vertical Distribution Patterns, Viviana A. Alder, Demetrio Boltovskoy Jan 1993

The Ecology Of Larger Microzooplankton In The Weddell-Scotia Confluence Area: Horizontal And Vertical Distribution Patterns, Viviana A. Alder, Demetrio Boltovskoy

Journal of Marine Research

The distribution of microzooplankton > 15 μm (large dinoflagellates, foraminifers, radiolarians, tintinnids, microcrustaceans and various invertebrate larvae) was studied in samples retrieved from 10 to 400 m in two overlapping transects along 49W, between 57S and 61°30′S (27 Nov.–12 Dec. 1988, and 27 Dec. 1988–4 Jan. 1989). Dinoflagellates and tintinnids concentrated at 50–90 m (10–400 m weighted averages, dinoflagellates: 103 ind./I, 131 mg C/m2; tintinnids: 9.7 ind./I, 53 mg C/m2). Copepod nauplii had a more variable vertical pattern with maximum numbers at 100–200 m (10–400 m av.: 2.6 ind./I, 27 mg C/m2). Foraminifers and radiolarians …

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Benthic Fluxes And Nitrogen Cycling In Sediments Of The Continental Margin Of The Eastern North Pacific, Allan H. Devol, John P. Christensen Jan 1993

Benthic Fluxes And Nitrogen Cycling In Sediments Of The Continental Margin Of The Eastern North Pacific, Allan H. Devol, John P. Christensen

Journal of Marine Research

The exchange of O2, N2, NO3−, NH4+, Si(OH)4, and PO4−3 between the sediments and the overlying water (benthic flux) was determined at 18 locations on the Washington State continental margin using an in situ benthic tripod. Oxygen consumption by the sediments ranged from 21.2 pmole cm−2 s−1 on the shelf to 2.85 pmole cm−2 s−1 on the slope. Nitrogen gas fluxes were from the sediments to the overlying water. They varied 5.5 to 1.2 pmole-N cm−2 s−1 …

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An Analytic Model Of Tidal Circulation In A Narrow Estuary, X. H. Wang, P. D. Craig Jan 1993

An Analytic Model Of Tidal Circulation In A Narrow Estuary, X. H. Wang, P. D. Craig

Journal of Marine Research

A simple model of open coastal dynamics is adapted to provide an analytic solution of the vertical and axial structure of tidal currents in an estuary. Applied to the Hey River estuary in northern Queensland, the model provides an accurate representation of the four major tidal constituents. By best-fit analysis of the model results to data from three current meters, the vertical eddy viscosity for the estuary is estimated as 2.8 × 10−3 m2s−1, and the linear friction coefficient as 8 × 10−4 ms−1. Bottom boundary considerations indicate that the data are …

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Release Rates Of Trace Elements And Protein From Decomposing Planktonic Debris. 1. Phytoplankton Debris, Byeong-Gweon Lee, Nicholas S. Fisher Jan 1993

Release Rates Of Trace Elements And Protein From Decomposing Planktonic Debris. 1. Phytoplankton Debris, Byeong-Gweon Lee, Nicholas S. Fisher

Journal of Marine Research

The release rates of Ag, Am, Cd, Ce, Co, Pb, Se and Zn from decomposing diatom cells were determined using gamma-emitting radiotracers; rates were compared with C and protein loss rates over time. Additionally, experiments were designed to evaluate various artifacts involved in the experimental use of radioisotopes, handling of biogenic debris, and the use of poisons. The release rates of C at 18°C exponentially decreased with time from 17.5% d−1 at 1 d to 2.7% d−1 at 6 d; those of protein slowed from 9.2% d−1 at 1 d to 2.0% d−1 at 6 d. …

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Potential Carbon Sources For The Head-Down Deposit-Feeding Polychaete Heteromastus Filiformis, Lisa M. Clough, Glenn R. Lopez Jan 1993

Potential Carbon Sources For The Head-Down Deposit-Feeding Polychaete Heteromastus Filiformis, Lisa M. Clough, Glenn R. Lopez

Journal of Marine Research

In this study we investigated potential carbon sources for the capitellid polychaete, Heteromastus filiformis. It is a head-down deposit feeder ingesting sediment from at least 15 cm below the sediment-water interface. This orientation appears to minimize the worm's ability to acquire food and oxygen and maximize its exposure to sulfide. The food sources we examined were metabolically active bacteria, benthic algae, detritus and chemoautotrophic bacteria. Carbon retention efficiencies from metabolically active bacteria, benthic algae and detritus by H. filiformis were 26%, 8% and 4% respectively. These values are relatively low compared to other deposit feeding species suggesting that H. …

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Prochlorococcus And Synechococcus: A Comparative Study Of Their Optical Properties In Relation To Their Size And Pigmentation, André Morel, Yu-Hwan Ahn, Frédéric Partensky, Daniel Vaulot, Hervé Claustre Jan 1993

Prochlorococcus And Synechococcus: A Comparative Study Of Their Optical Properties In Relation To Their Size And Pigmentation, André Morel, Yu-Hwan Ahn, Frédéric Partensky, Daniel Vaulot, Hervé Claustre

Journal of Marine Research

Three unialgal strains of Prochlorococcus and four of Synechococcus were grown in batch culture at low irradiances. The spectral values of light absorption, scattering and backscattering of intact cells in suspension were determined, together with cell counts, size distribution and pigment composition (via HPLC). The spectral efficiency factors Qa, Qb, Qbb for light absorption, scattering and backscattering respectively, were derived, as well as the corresponding chlorophyll-specific coefficients a*, b* and bb*. The pigment used when normalizing is “true” chlorophyll a for Synechococcus, and divinyl-chlorophyll a for Prochlorococcus. In correspondence …

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Effects Of Poisons And Preservatives On The Fluxes And Elemental Compositions Of Sediment Trap Materials, John I. Hedges, Cindy Lee, Stuart G. Wakeham, Peter J. Hernes, Michael L. Peterson Jan 1993

Effects Of Poisons And Preservatives On The Fluxes And Elemental Compositions Of Sediment Trap Materials, John I. Hedges, Cindy Lee, Stuart G. Wakeham, Peter J. Hernes, Michael L. Peterson

Journal of Marine Research

Bulk particle fluxes and organic elemental compositions were compared among sediment traps treated with different poisons and preservatives. The traps (3:1 open cylinders) were deployed for 1–2 months at 30 and 60 m depths in a coastal marine environment. The tested treatments included mercuric chloride, mixed antibiotics, sodium azide, formalin, chloroform, and salt, along with untreated controls. Fluxes of bulk particulate material and weight percentages of organic carbon measured for differently treated traps deployed simultaneously at the same depth both varied by an average of ±8% of the mean value. Great numbers of large (>850 μm) zooplankton swimmers were …

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Effects Of Poisons And Preservatives On The Composition Of Organic Matter In A Sediment Trap Experiment, Stuart G. Wakeham, John I. Hedges, Cindy Lee, Tamara K. Pease Jan 1993

Effects Of Poisons And Preservatives On The Composition Of Organic Matter In A Sediment Trap Experiment, Stuart G. Wakeham, John I. Hedges, Cindy Lee, Tamara K. Pease

Journal of Marine Research

Fluxes and molecular compositions of a group of major biochemical classes (lipids, lignin, pigments, amino acids, and carbohydrates) were compared among sediment traps treated with different poisons and preservatives and deployed for 1–2 months in a coastal marine environment. Fluxes and compositions of biochemicals were significantly more variable than bulk particle fluxes and elemental compositions. This observation was attributed to a greater influence of dead zooplankton “swimmers” in treated traps rather than differences in microbial decomposition due to the various treatments. Molecular compositions, especially of lipids, confirm the influence of zooplankton swimmers on the biochemical composition of the particulate material …

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Deep Circulation In The Tropical North Atlantic, Marjorie A. M. Friedrichs, Melinda M. Hall Jan 1993

Deep Circulation In The Tropical North Atlantic, Marjorie A. M. Friedrichs, Melinda M. Hall

Journal of Marine Research

A transatlantic CTD/ADCP (Conductivity, Temperature, Depth/Acoustic Doppler Current Profiler) section along 11N, taken in March 1989, has been used to compute geostrophic velocities; geostrophic transport is required to balance in situ values of the Ekman and shallow boundary current transports. The horizontal flow structure is described for eight layers, with particular emphasis on deep and bottom waters (four layers below  = 4.7°C). In the shallow layers, total North Brazil Current (NBC) transport agrees with other observations previously made in the month of March, while net northward flow of these layers across the western basin is also consistent with recent …

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Advection And Eddy Mixing In The Mediterranean Salt Tongue, Michael A. Spall, Philip L. Richardson, James Price Jan 1993

Advection And Eddy Mixing In The Mediterranean Salt Tongue, Michael A. Spall, Philip L. Richardson, James Price

Journal of Marine Research

Lagrangian trajectories from the SOFAR float Mediterranean outflow experiment are used to estimate the low frequency variability and mixing in the vicinity of the Mediterranean salt tongue. Two dominant patterns of Lagrangian variability are observed, (1) nearly zonal low frequency motions and (2) wave-like oscillations with northwest to southeast orientation. The zonal motions are found near the core of the salt tongue in the Canary Basin while the oscillations are generally found to the south and east. It is suggested that the zonal motions are the result of baroclinic instability of the large-scale flow. They have zonally enhanced low frequency …

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The Splitting Of Eddies Along Boundaries, Chuan Shi, Doron Nof Jan 1993

The Splitting Of Eddies Along Boundaries, Chuan Shi, Doron Nof

Journal of Marine Research

This paper addresses the question of what happens to an eddy that is forced “violently” against a boundary by, say, an advective current or another vortex. The detailed temporal evolution of such a collision on an f-plane is examined using a barotropic, as well as a one-and-a-half-layer contour dynamics model with surgery procedures. Both the barotropic eddy and the one-and-a-half-layer eddy initially have two circular potential vorticity fronts: an inner front at which the velocity increases to a maximum from zero at its center, and an outer front (e.g., the edge of the eddy) at which the velocity reduces …

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