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An Assessment Of The Use Of Sediment Traps For Estimating Upper Ocean Particle Fluxes, Ken O. Buesseler, Avan N. Antia, Min Chen, Scott W. Fowler, Wilford D. Gardner, Orjan Gustafsson, Koh Harada, Anthony F. Michaels, Michiel Rutgers Van Der Loeff, Manmohan Sarin, Deborah K. Steinberg, Thomas Trull Jan 2007

An Assessment Of The Use Of Sediment Traps For Estimating Upper Ocean Particle Fluxes, Ken O. Buesseler, Avan N. Antia, Min Chen, Scott W. Fowler, Wilford D. Gardner, Orjan Gustafsson, Koh Harada, Anthony F. Michaels, Michiel Rutgers Van Der Loeff, Manmohan Sarin, Deborah K. Steinberg, Thomas Trull

Journal of Marine Research

This review provides an assessment of sediment trap accuracy issues by gathering data to address trap hydrodynamics, the problem of zooplankton "swimmers," and the solubilization of material after collection. For each topic, the problem is identified, its magnitude and causes reviewed using selected examples, and an update on methods to correct for the potential bias or minimize the problem using new technologies is presented. To minimize hydrodynamic biases due to flow over the trap mouth, the use of neutrally buoyant sediment traps is encouraged. The influence of swimmers is best minimized using traps that limit zooplankton access to the sample …

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Mismatch Between Community Respiration And The Contribution Of Heterotrophic Bacteria In The Ne Atlantic Open Ocean: What Causes High Respiration In Oligotrophic Waters?, Xosé Anxelu G. Morán, Valesca Pérez, Emilio Fernández Jan 2007

Mismatch Between Community Respiration And The Contribution Of Heterotrophic Bacteria In The Ne Atlantic Open Ocean: What Causes High Respiration In Oligotrophic Waters?, Xosé Anxelu G. Morán, Valesca Pérez, Emilio Fernández

Journal of Marine Research

Heterotrophic bacteria have long been considered as the major respirers of the open ocean. During a survey in the eastern N Atlantic Subtropical Gyre we measured 3H-leucine heterotrophic bacterial production (BP), 14C particulate primary production (PPP) and the O2 community metabolism rates: gross primary production (GPP), net community production (NCP) and community respiration (CR). We estimated heterotrophic bacterial respiration (BR) from BP and literature models of bacterial growth efficiency [BGE = BP/(BP + BR)]. BP was an order of magnitude lower than PPP (integrated means of 17 ± 2 and 207 ± 29 mg C m−2 …

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Hurricane-Induced Destratification And Restratification In A Partially-Mixed Estuary, Ming Li, Liejun Zhong, William C. Boicourt, Shunli Zhang, Da-Lin Zhang Jan 2007

Hurricane-Induced Destratification And Restratification In A Partially-Mixed Estuary, Ming Li, Liejun Zhong, William C. Boicourt, Shunli Zhang, Da-Lin Zhang

Journal of Marine Research

Hurricane Isabel made landfall at the Outer Banks of North Carolina and moved past Chesapeake Bay on 18 –19 September 2003. The baroclinic response of this partially-mixed estuary to the passage of Isabel is investigated using the output from a regional atmosphere-ocean model. The hurricane-forced winds caused gradual deepening of the surface mixed layer, followed by rapid destratification in the water-column. The mixed-layer deepening appears to be driven by velocity shear and can be interpreted by a gradient Richardson number. Although strong winds caused complete mixing locally, a large longitudinal salinity gradient of about 10-4 psu m-1 persisted …

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The Variability And Heat Budget Of The Upper Ocean Under The Chile-Peru Stratus, Keir Colbo, Robert Weller Jan 2007

The Variability And Heat Budget Of The Upper Ocean Under The Chile-Peru Stratus, Keir Colbo, Robert Weller

Journal of Marine Research

The persistent stratus clouds found west of Chile and Peru are important for the coupling of the ocean and atmosphere in the eastern Pacific and thus in the climate of the region. The relatively cool sea-surface temperatures found west of Peru and northern Chile are believed to play a role in maintaining the stratus clouds over the region. In October 2000 a buoy was deployed at 20S, 85W, a site near the center of the stratus region, in order to examine the variability of sea-surface temperature and the temporal evolution of the vertical structure of the upper ocean. The buoy …

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Simulated Fiddler-Crab Sediment Mixing, Katherine Huang, Bernard P. Boudreau, Daniel C. Reed Jan 2007

Simulated Fiddler-Crab Sediment Mixing, Katherine Huang, Bernard P. Boudreau, Daniel C. Reed

Journal of Marine Research

Using a lattice-automaton model, we simulate the effects of fiddler crabs on the distribution of excess 210Pb in marsh sediments. Three previously-identified modes of bioturbation are investigated: (1) removal-and-fill, where material is excavated to the sediment-water interface and burrows, when abandoned, are subsequently filled by surface material, (2) removal-and-collapse, where the infilling occurs by collapse of the burrow walls, and (3) partial-compaction-and-collapse, where part of the excavated sediment is packed into the burrow wall and abandoned burrows subsequently collapse. These various mixing modes lead to somewhat different laterally-integrated 210Pbex profiles, which are also influenced …

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Field Investigation On Seawater Temperature Variability In Relation To Horizontal Optical Gradient, Maciej Matciak, Bozena Wojtasiewicz Jan 2007

Field Investigation On Seawater Temperature Variability In Relation To Horizontal Optical Gradient, Maciej Matciak, Bozena Wojtasiewicz

Journal of Marine Research

The spatial variability of radiant energy absorption in seawater can result from the non-homogeneity of the concentration of its optically active components, such as chlorophyll or dissolved organic matter. This non-homogeneity leads to local changes in the radiant heating rate and consequent changes in water temperature. Besides a simple dependence, for instance when a higher phytoplankton concentration is accompanied by a temperature rise, a relation that is more complex may occur. A theoretical analysis suggested that sufficiently strong horizontal changes in seawater absorption may cause, in their close proximity, an additional increase or decrease in the heating rate. To confirm …

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Thermohaline Structure And Variability In The Eastern Nansen Basin As Seen From Historical Data, David Walsh, Igor Polyakov, Leonid Timokhov, Eddy Carmack Jan 2007

Thermohaline Structure And Variability In The Eastern Nansen Basin As Seen From Historical Data, David Walsh, Igor Polyakov, Leonid Timokhov, Eddy Carmack

Journal of Marine Research

Newly available historical Russian data are used to quantify year-to-year variations in the structure and properties of the halocline and Atlantic Water layers in the eastern Nansen Basin. The data come from a series of aerial surveys of the central Arctic Ocean done during winter between 1973 and 1979, and repeated "Polygon" surveys of the shelf, slope, and basin north of Severnaya Zemlya in the 1980s, and thus allow a perspective on shelf-basin exchange. A water-mass census shows substantial survey-to-survey variability in several water-mass categories, with volumetric fluctuations of ∼17% in the Upper Polar Deep Water category, ∼14% in Atlantic …

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Spatial Continuity Of Measured Seawater And Tracer Fluxes Through Nares Strait, A Dynamically Wide Channel Bordering The Canadian Archipelago, Andreas Münchow, Kelly K. Falkner, Humfrey Melling Jan 2007

Spatial Continuity Of Measured Seawater And Tracer Fluxes Through Nares Strait, A Dynamically Wide Channel Bordering The Canadian Archipelago, Andreas Münchow, Kelly K. Falkner, Humfrey Melling

Journal of Marine Research

Freshwater delivered as precipitation and runoff to the North Pacific and Arctic oceans returns to the Atlantic principally via the Canadian polar shelf and Fram Strait. It is conveyed as ice or freshened seawater. Here we use detailed ship-based measurements to calculate a snap-shot of volume, freshwater, and tracer fluxes through Nares Strait, a 500-km long waterway separating Greenland and Ellesmere Island. We use quasi-synoptic observations of current by ship-mounted acoustic Doppler current profiler (ADCP), of salinity and temperature by CTD probe and of dissolved nutrients by rosette bottle sampler on four cross-sections between 82 and 78N latitude. Data were …

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The Role Of Westward Intensification In Potential Vorticity Homogenization, Toshihiro Sakamoto Jan 2007

The Role Of Westward Intensification In Potential Vorticity Homogenization, Toshihiro Sakamoto

Journal of Marine Research

Using a two-layer quasigeostrophic model with weak interfacial and bottom friction we propose a mechanism for potential vorticity homogenization in a non-eddying, wind-driven gyre closed through a viscous western boundary layer, to which the previous theory based on the Prandtl–Batchelor theorem cannot be applied. It is shown that there exist steady states in which the lower-layer potential vorticity in a large pool of closed geostrophic contours becomes substantially uniform. The homogenization process is dominated by advection and thus completed within a single passage through the gyre. This is because an O (1) anomaly of potential vorticity that is comparable to …

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Dissipation In Hydraulic Transitions In Flows Through Abyssal Channels, S. A. Thorpe Jan 2007

Dissipation In Hydraulic Transitions In Flows Through Abyssal Channels, S. A. Thorpe

Journal of Marine Research

There is growing evidence from observations that mixing occurs in hydraulic jumps, or flow transitions, downstream of sills within channels connecting deep ocean basins or within submarine canyons on the flanks of mid-ocean ridges. Models with continuous profiles of velocity and density upstream and downstream of a transition, but conforming to continuity conditions, are devised to represent the mixing that occurs in a hydraulic jump in a stratified shear flow of finite depth moving over a horizontal boundary in a deep fluid. These are used to assess the conditions in which transitions may occur and to provide an estimate of …

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Oxygen And Nitrogen Cycling In The Northeast Pacific – Simulations And Observations At Station Papa In 2003/2004, N. Steiner, S. Vagle, K. Denman, C. Mcneil Jan 2007

Oxygen And Nitrogen Cycling In The Northeast Pacific – Simulations And Observations At Station Papa In 2003/2004, N. Steiner, S. Vagle, K. Denman, C. Mcneil

Journal of Marine Research

A long-term air-sea exchange mooring has been maintained in the North Pacific near Ocean Station Papa (OSP, 145W, 50N) since September 2002 as part of the Canadian Surface Ocean Lower Atmosphere Study (C-SOLAS). The mooring provides a new long-term data set for gas measurements. In addition to Conductivity, Temperature and Depth (CTD) recorders at two depths, the mooring is equipped with ProOceanus Gas Tension Devices (GTDs) measuring the total gas pressure at four different depths, two oxygen sensors, two fluorometers for chlorophyll estimates, and an upward-looking 200 kHz echo-sounder for bubble measurements. Chlorophyll data have been added using SeaWiFS imagery …

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Phytoplankton Pigment Distribution In The Northwestern Alboran Sea And Meteorological Forcing: A Remote Sensing Study, D. Macías, G. Navarro, F. Echevarría, C. M. García, J. L. Cueto Jan 2007

Phytoplankton Pigment Distribution In The Northwestern Alboran Sea And Meteorological Forcing: A Remote Sensing Study, D. Macías, G. Navarro, F. Echevarría, C. M. García, J. L. Cueto

Journal of Marine Research

A set of weekly-composite SeaWiFS (Sea-viewing Wide Field of view Sensor) imagery (from 1998 to 2004) has been used to asses the temporal and spatial variability of the surface chlorophyll distribution in the Northwestern Alboran Sea. Empirical Orthogonal Function (EOF) analysis of the images series shows the existence of three different regions in which surface chlorophyll presents a homogeneous temporal behavior in the neighborhood of the Strait of Gibraltar.The temporal patterns of surface chlorophyll concentrations in each region have been characterized by studying the role of several forcing factors, mainly the zonal component of the wind field.The first identified region …

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The Geography Of Linear Baroclinic Instability In Earth’S Oceans, K. Shafer Smith Jan 2007

The Geography Of Linear Baroclinic Instability In Earth’S Oceans, K. Shafer Smith

Journal of Marine Research

Satellite observations reveal a mesoscale oceanic circulation dominated by turbulence that is correlated, in most cases, with local baroclinicity. Linear baroclinic instability theory has proved useful in understanding the time and space scales of atmospheric eddies. The question addressed here is, to what degree can the observed oceanic eddy activity be understood through a local, linear stability analysis? This question is addressed as follows. A local quasigeostrophic linear stability calculation is performed on a grid of wavenumbers, ranging in magnitude about the local deformation wavenumber, for each vertical profile in a dataset of neutral density for the world's oceans. The …

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Transient Tracer Dynamics In A Lattice-Automaton Model Of Bioturbation, Daniel C. Reed, Bernard P. Boudreau, Katherine Huang Jan 2007

Transient Tracer Dynamics In A Lattice-Automaton Model Of Bioturbation, Daniel C. Reed, Bernard P. Boudreau, Katherine Huang

Journal of Marine Research

Mixing of sediments by benthic fauna represents a dominant transport process of solids in the majority of surficial marine deposits. Short-term mixing rates are often determined by fitting a transient, diffusive model of bioturbation to vertical profiles of introduced particles (e.g., luminophores). Previous field studies adopting this approach have noted that mixing intensity decreases with time and the nature of mixing progresses from advective or nonlocal transport to diffusive mixing. These observations have been attributed to "age-dependent" mixing. The present study employs a lattice-automaton model to investigate the short-term behavior of conservative transient tracers. Simulations demonstrate that despite constant, indiscriminate …

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On The Vorticity Cycle Of The Loop Current, A. Lugo-Fernández, A. Badan Jan 2007

On The Vorticity Cycle Of The Loop Current, A. Lugo-Fernández, A. Badan

Journal of Marine Research

The inrushing/retraction behavior of the Loop Current (LC) in the eastern Gulf of Mexico can be represented by a recurrent cycle of vorticity input/output with a time scale of 0 to 16 months. This cycle is brought about as a balance between the accumulation of absolute vorticity in the LC and deep advection of vorticity to the Caribbean Sea. The vorticity time scale is directly proportional to the change in circulation around the LC and 2πH/Q0(f0 + ζ0); where H (∼800 m) is the thickness of the LC, Q0 is …

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The Enso Signature In Sea-Surface Temperature In The Gulf Of California, Hugo Herrera-Cervantes, Daniel B. Lluch-Cota, Salvador E. Lluch-Cota, Guillermo Gutiérrez-De-Velasco S Jan 2007

The Enso Signature In Sea-Surface Temperature In The Gulf Of California, Hugo Herrera-Cervantes, Daniel B. Lluch-Cota, Salvador E. Lluch-Cota, Guillermo Gutiérrez-De-Velasco S

Journal of Marine Research

We analyzed 21 years of sea-surface temperature satellite images to explore the spatial signature of the El Niño-Southern Oscillation signal in the Gulf of California. We used empirical orthogonal function analysis to extract the principal mode of the nonseasonal sea-surface temperature variability and compared it to the spatial signature of the Southern Oscillation Index. The first mode accounted for 80% of nonseasonal variability and its amplitude time series was significantly correlated to the Southern Oscillation Index (r = −0.58,P < 0.01). The amplitude of this mode and its statistical relation to the El Niño is stronger during winter, which suggests that forcing of sea-surface temperature variability occurs through the disruption of the wind-driven upwelling corridor along the eastern coast due to El Niño-related atmospheric teleconnections. We also examined weekly time series of coastal sea-surface temperature coastal anomalies along the coast of North America, including the interior of the Gulf of California, during the strong 1997–98 El Niño. We found a poleward propagating signal that reached the mouth of the Gulf of California at the end of spring and continued its poleward propagation along the west coast of the peninsula slightly delayed; it also resulted in warming inside the Gulf of California. This observation may provide an explanation for the variable extension of the El Niño signature along the Pacific coast of North America.

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Water Column Stability And Spring Bloom Dynamics In The Gulf Of Alaska, Stephanie A. Henson Jan 2007

Water Column Stability And Spring Bloom Dynamics In The Gulf Of Alaska, Stephanie A. Henson

Journal of Marine Research

The initiation of the Gulf of Alaska phytoplankton spring bloom is light limited, and therefore the onset of stratification is critical to primary productivity. A stability ratio, which represents the balance between mixing (tide and wind) and buoyancy (heat and freshwater) processes, is defined. When buoyancy dominates over mixing, stratification is possible. Use of model- and satellite-derived data allows maps of the spatial and temporal development of stratification to be constructed. Spatial variability in the dominant forcing components is also mapped. The onset of water column stability is closely linked to the timing of the phytoplankton spring bloom. Consideration of …

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Simulations Of Phytoplankton Species And Carbon Production In The Equatorial Pacific Ocean 2. Effects Of Physical And Biogeochemical Processes, Baris Salihoglu, Eileen E. Hofmann Jan 2007

Simulations Of Phytoplankton Species And Carbon Production In The Equatorial Pacific Ocean 2. Effects Of Physical And Biogeochemical Processes, Baris Salihoglu, Eileen E. Hofmann

Journal of Marine Research

A one-dimensional multi-component lower trophic level ecosystem model that includes detailed algal physiology is used to investigate the response of phytoplankton community and carbon production and export to variations in physical and biochemical processes in the Cold Tongue region of the equatorial Pacific Ocean at 0N, 140W. Results show that high-frequency variability in vertical advection and temperature is an important mechanism driving the carbon export. Filtering out low frequency physical forcing results in a 30% increase in primary production and dominance of high-light adapted Prochlorococcus and autotrophic eukaryotes. Sensitivity studies show that iron availability is the primary control on carbon …

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Rapid Consumption Of Phytoplankton And Ice Algae By Arctic Soft-Sediment Benthic Communities: Evidence Using Natural And 13c-Labeled Food Materials, Ming-Yi Sun, Michael L. Carroll, William G. Ambrose Jr., Lisa M. Clough, Li Zou, Glenn R. Lopez Jan 2007

Rapid Consumption Of Phytoplankton And Ice Algae By Arctic Soft-Sediment Benthic Communities: Evidence Using Natural And 13c-Labeled Food Materials, Ming-Yi Sun, Michael L. Carroll, William G. Ambrose Jr., Lisa M. Clough, Li Zou, Glenn R. Lopez

Journal of Marine Research

Reduction of sea ice in the Arctic may significantly alter the relative fluxes of phytoplankton and ice algae to the seafloor. To examine the response of Arctic benthic communities to changing food supplies, we incubated sediment cores collected from two sites (Smeerenburg Fjord, northwest Svalbard in May 2003 and Storfjord Trench, Barents Sea in May 2004) with controlled additions of natural phytoplankton and ice algal assemblages, and laboratory-cultured 13C-labeled ice algae (Nitzschia frigida, in 2004 only). We measured sediment respiration, pigments, lipid biomarkers, and compound-specific δ13C signals over the course of incubations. Both communities responded …

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Modeling Sensitivity Of Biodiffusion Coefficient To Seasonal Bioturbation, Pascal Lecroart, Sabine Schmidt, Pierre Anschutz, Jean-Marie Jouanneau Jan 2007

Modeling Sensitivity Of Biodiffusion Coefficient To Seasonal Bioturbation, Pascal Lecroart, Sabine Schmidt, Pierre Anschutz, Jean-Marie Jouanneau

Journal of Marine Research

Biodiffusion coefficient is the predominant parameter used to constrain biological activity in marine sediments. Bioturbation characterization is important because of the dominant role it plays on the flux determination through the sediment-water interface. Biological mixing is quantified through models of radionuclides diagenesis by both a biodiffusion coefficient (Db) and a mixed depth (L) under the basic steady-state assumption. Based on a new global compilation of radionuclide data in marine sediments and on previously published modeling results, we show that short-live radionuclides are perfectly devoted to quantify biological mixing for sediments associated with λL2/Db lower than 125, λ representing …

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Notes On The Modeling Of Methane In Aging Hydrothermal Plumes, G. C. Nihous, S. M. Masutani Jan 2007

Notes On The Modeling Of Methane In Aging Hydrothermal Plumes, G. C. Nihous, S. M. Masutani

Journal of Marine Research

Marine hydrothermal vent fields represent a unique environment for the study of aerobic microbial methane oxidation because of high methane concentrations and limited spatial and temporal scales. Earlier data collected in lateral plumes at the Endeavour Segment of the Juan de Fuca Ridge, including methane concentration, methane oxidation rate and stable carbon isotopic composition (δ13C), are carefully interpreted with a suite of simple analytical models. Methane oxidation is defined with a rate constant k as a first order process with respect to both substrate and methanotroph concentration. This elementary formalism coupled with simplified representations of advection and …

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Greenland’S Island Rule And The Arctic Ocean Circulation, Terrence M. Joyce, Andrey Proshutinsky Jan 2007

Greenland’S Island Rule And The Arctic Ocean Circulation, Terrence M. Joyce, Andrey Proshutinsky

Journal of Marine Research

In order to explain observed southward water transport of 2-3 Sv through Davis Strait, a simple extension of Godfrey's (1989) Island Rule and a 2-D idealized numerical model simulations were made for the flow around Greenland. Godfrey's theory has been extended to permit inclusion of Bering Strait inflow and bottom friction to represent the dissipation supplied by the porous Canadian Archipelago in the modeled flow west of Greenland. In both models, the forcing has been applied in a quasi-steady manner to the circulation via climatologic wind stresses and using wind forcing for the high and low Arctic Oscillation (AO) index …

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Constraining Bubble Dynamics And Mixing With Dissolved Gases: Implications For Productivity Measurements By Oxygen Mass Balance, Roberta C. Hamme, Steven R. Emerson Jan 2006

Constraining Bubble Dynamics And Mixing With Dissolved Gases: Implications For Productivity Measurements By Oxygen Mass Balance, Roberta C. Hamme, Steven R. Emerson

Journal of Marine Research

We used a dynamic mixed layer model to determine carbon export by the oxygen mass balance method from a time series of O2/Ar, N2/Ar and Ne measurements collected at station ALOHA near Hawaii from July 2000 to June 2001. The inert gas measurements constrain the flux of oxygen into the mixed layer from small, collapsing bubbles (injection) to be greater than or equal to the flux from larger bubbles (exchange), with mean estimates of the ratio in the range of 1–2. We also show that monthly observations of temperature and inert gases cannot constrain the rate …

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Generalized Inversion Of The Gent-Cane Model Of The Tropical Pacific With Tropical Atmosphere-Ocean (Tao) Data, A. F. Bennett, B. S. Chua, H. E. Ngodock, D. E. Harrison, M. J. Mcphaden Jan 2006

Generalized Inversion Of The Gent-Cane Model Of The Tropical Pacific With Tropical Atmosphere-Ocean (Tao) Data, A. F. Bennett, B. S. Chua, H. E. Ngodock, D. E. Harrison, M. J. Mcphaden

Journal of Marine Research

We here describe the results of our latest effort to reanalyze TAO monthly mean surface and subsurface temperature observations constrained by a tropical Pacific ocean model, and simultaneously to evaluate the physical consistency of the observations and the model. Both tasks are executed by weak–constraint, four–dimensional variational assimilation of the observations into the model. In this study our reanalysis employs the reduced–gravity Gent–Cane model, combined with the 'KPP–interior' parameterization of vertical turbulent fluxes. With the limited vertical resolution adopted in previous studies of this model, the 'W4DVAR' or inverse method fails to produce an acceptable reanalysis, as the dynamical residuals …

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Shear And Turbulence Production Across Subtidal Channels, David K. Ralston, Mark T. Stacey Jan 2006

Shear And Turbulence Production Across Subtidal Channels, David K. Ralston, Mark T. Stacey

Journal of Marine Research

In intertidal regions with subtidal channels, effects of bathymetry on overlying flow vary greatly with tidal stage. Around low water when mudflats and marsh are exposed, flow is constrained to channels, but when water depths are greater, tidal forcing may not necessarily be aligned with meandering channel axes. Flow across the channel can generate strong shear and turbulence at the elevation of the channel banks and can significantly increase turbulent energy in the middle of the water column. Field observations in a mudflat channel of San Francisco Bay indicate that cross-channel shear regularly occurs there early in ebb tides. With …

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Physical-Biological Interactions And Their Effect On Phytoplankton Blooms In Fjords And Near-Coastal Waters, Lars Erik Holmedal, Torbjørn Utnes Jan 2006

Physical-Biological Interactions And Their Effect On Phytoplankton Blooms In Fjords And Near-Coastal Waters, Lars Erik Holmedal, Torbjørn Utnes

Journal of Marine Research

A one-dimensional flow model which accounts for turbulence and stratification in the upper ocean has been applied in conjunction with a one-dimensional production-advection-diffusion model to predict the initial evolution of the phytoplankton biomass concentration under given biological and physical conditions. Here the stratification is caused by the salinity which is modeled by a one-dimensional diffusion equation; the density is related to the salinity by a linear relation (state equation). The resulting one-dimensional model has been applied to investigate how local physical conditions affect the initiation of phytoplankton blooms in nutrition rich waters characterized by wind driven currents and salinity stratification. …

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An Estuarine Box Model Of Freshwater Delivery To The Coastal Ocean For Use In Climate Models, Richard W. Garvine, Michael M. Whitney Jan 2006

An Estuarine Box Model Of Freshwater Delivery To The Coastal Ocean For Use In Climate Models, Richard W. Garvine, Michael M. Whitney

Journal of Marine Research

Present day climate models employ a coarse horizontal grid that is unable to fully resolve estuaries or continental shelves. The importation of fresh water from rivers is critical to the state of deep ocean stratification, but currently the processing of that fresh water as it passes from the river through the estuary and adjacent shelf is not represented in the coastal boundary conditions of climate models. An efficient way to represent this input of fresh water to the deep ocean would be to treat the estuary and shelf domains as two coupled box models with river water input to the …

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On The Mechanism Of Centennial Thermohaline Oscillations, Florian Sévellec, Thierry Huck, Mahdi Ben Jelloul Jan 2006

On The Mechanism Of Centennial Thermohaline Oscillations, Florian Sévellec, Thierry Huck, Mahdi Ben Jelloul

Journal of Marine Research

Centennial oscillations of the ocean thermohaline circulation are studied in a 2-D latitude-depth model under mixed boundary conditions (i.e. restoring surface temperature and prescribed freshwater flux). The oscillations are revealed through linear stability analysis of a steady state obtained in a single hemisphere configuration. A density variance budget is performed and helps determine the physical processes sustaining these oscillations: the restoring surface temperature appears as a source of density variance – this is a consequence of positively-correlated temperature and salinity anomalies. A minimal model, the Howard-Malkus loop oscillator, enables us to understand physically the oscillatory and growth mechanisms. The centennial …

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Analysis Of Instabilities And Mesoscale Motion In A Terrain-Following Coordinate Ocean Model, Ingerid Fossum, Lars Petter Røed Jan 2006

Analysis Of Instabilities And Mesoscale Motion In A Terrain-Following Coordinate Ocean Model, Ingerid Fossum, Lars Petter Røed

Journal of Marine Research

We perform a combined potential vorticity analysis and energy analysis to analyze instabilities and mesoscale motion in a continuously stratified, terrain-following coordinate ocean model. Care is exercised to ensure that the potential vorticity is conserved along isopycnals in the absence of sources and sinks. We also derive expressions for the energy components and the associated conversion terms suitable for a terrain-following coordinate ocean model. To demonstrate the usefulness of the new combined analysis tool for detection of instabilities, we analyze results from a numerical model experiment in which the ocean model is contained in a long, rectangular channel closed at …

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Carbon Flows Through A Benthic Food Web: Integrating Biomass, Isotope And Tracer Data, Dick Van Oevelen, Karline Soetaert, Jack J. Middelburg, Peter M. J. Herman, Leon Moodley, Ilse Hamels, Tom Moens, Carlo H. R. Heip Jan 2006

Carbon Flows Through A Benthic Food Web: Integrating Biomass, Isotope And Tracer Data, Dick Van Oevelen, Karline Soetaert, Jack J. Middelburg, Peter M. J. Herman, Leon Moodley, Ilse Hamels, Tom Moens, Carlo H. R. Heip

Journal of Marine Research

The herbivorous, detrital and microbial pathways are major components of marine food webs. Although it is commonly recognized that these pathways can be linked in several ways, elucidating carbon transfers between or within these pathways remains a challenge. Intertidal flat communities are driven by a wide spectrum of organic matter sources that support these different pathways within the food web. Here we reconstruct carbon pathways using inverse analysis based on mass balancing, stable isotope signatures and tracer data. Data were available on biomass, total carbon production and processing, integrated diet information from stable isotope signatures and the transfer of recently …

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