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Modeling Estuarine Ingress Of Blue Crab Megalopae: Effects Of Temporal Patterns In Larval Release, Charles E. Tilburg, Colleen D. Kernehan, Alex Andon, Charles E. Epifanio Jan 2008

Modeling Estuarine Ingress Of Blue Crab Megalopae: Effects Of Temporal Patterns In Larval Release, Charles E. Tilburg, Colleen D. Kernehan, Alex Andon, Charles E. Epifanio

Journal of Marine Research

The Atlantic blue crab Callinectes sapidus is an important predator in estuarine ecosystems and supports a large commercial fishery throughout its range. Settlement of blue crab megalopae in juvenile nurseries is episodic and is controlled by the combined effect of buoyancy- and wind-driven transport processes. Modeling studies have succeeded in hind-casting the temporal pattern of megalopal settlement but not the magnitude of individual settlement events. This shortcoming has been attributed to the lack of information concerning larval release by the adult spawning population. In this paper we present results of a set of field and modeling studies designed to test …

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Episodic Downwelling Predicts Recruitment Of Atlantic Cod, Greenland Cod And White Hake To Newfoundland Coastal Waters, D. W. Ings, R. S. Gregory, D. C. Schneider Jan 2008

Episodic Downwelling Predicts Recruitment Of Atlantic Cod, Greenland Cod And White Hake To Newfoundland Coastal Waters, D. W. Ings, R. S. Gregory, D. C. Schneider

Journal of Marine Research

Recruitment in marine fish is influenced by abiotic and biotic processes operating at many spatial and temporal scales. Annual recruitment to fisheries has received more attention at the scale of the population than at finer temporal scales, where spatially heterogeneous biological processes modify year-class success. We tested two hypotheses: (1) that recruitment of marine fish to the nearshore benthos at a fine temporal scale is determined by downwelling associated with onshore winds and (2) that fish arrival nearshore is related to tidal stage. During summer and autumn 1998 to 2001 and late spring to autumn 2002, we monitored recruitment of …

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Measuring Turbulent Large-Eddy Structures With An Adcp. 1. Vertical Velocity Variance, A. E. Gargett, A. E. Tejada-Martínez, C. E. Grosch Jan 2008

Measuring Turbulent Large-Eddy Structures With An Adcp. 1. Vertical Velocity Variance, A. E. Gargett, A. E. Tejada-Martínez, C. E. Grosch

Journal of Marine Research

Two different turbulent flows, Langmuir supercells and unstable convection, have been sampled with a VADCP, an acoustic Doppler current profiler (ADCP) with an additional vertical (V) beam. Direct measurements of the profile of vertical velocity variance provided by the vertical beam are used to calculate observational response functions for algorithms used to derive vertical velocity from the 4 beams of a standard ADCP. A theoretical response function derived for the vertical velocity estimate from a single pair of opposed slant beams illustrates the importance of large-scale quasi-coherent flow structures, as well as effects of different angles of slant beams from …

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Ocean Color Data Assimilation With Material Conservation For Improving Model Estimates Of Air-Sea Co2 Flux, John C. P. Hemmings, Rosa M. Barciela, Michael J. Bell Jan 2008

Ocean Color Data Assimilation With Material Conservation For Improving Model Estimates Of Air-Sea Co2 Flux, John C. P. Hemmings, Rosa M. Barciela, Michael J. Bell

Journal of Marine Research

A nitrogen balancing scheme for ocean color data assimilation in general circulation models is described and its potential for improving air-sea CO2 flux estimates is demonstrated. Given increments for phytoplankton, obtainable from a univariate surface chlorophyll analysis, the scheme determines mixed layer concentration increments for the other nitrogen pools: zooplankton, detritus and dissolved inorganic nitrogen (DIN). The fraction of the phytoplankton increment to be balanced by changing DIN varies dynamically with the likely contributions of phytoplankton growth and loss errors to the error in the background state. Further increments are applied below the mixed layer wherever positive DIN increments …

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The Impact Of Spatial Wind Variations On Freshwater Transport By The Alaska Coastal Current, John Rogers-Cotrone, Alexander E. Yankovsky, Thomas J. Weingartner Jan 2008

The Impact Of Spatial Wind Variations On Freshwater Transport By The Alaska Coastal Current, John Rogers-Cotrone, Alexander E. Yankovsky, Thomas J. Weingartner

Journal of Marine Research

The Alaska Coastal Current (ACC) is located in a region with prevailing downwelling-favorable winds, flows over a long stretch of coastline (over 2000 km), and is driven by multiple sources of freshwater discharge totaling 24000 m3 s–1 along its length. Using the Regional Ocean Modeling System (ROMS) we attempt to determine how spatially variable winds affect the downstream transport of freshwater along a long coastline with nearly continuous sources of freshwater. The model domain represents a fraction of the ACC region and periodic boundary conditions are applied to allow propagation of the buoyant flow from upstream. The model …

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Observations Of Coastal Upwelling Off Uruguay Downshelf Of The Plata Estuary, South America, Felipe Pimenta, Richard W. Garvine, Andreas Münchow Jan 2008

Observations Of Coastal Upwelling Off Uruguay Downshelf Of The Plata Estuary, South America, Felipe Pimenta, Richard W. Garvine, Andreas Münchow

Journal of Marine Research

We analyze hydrographic and current observations of an upwelling center off eastern South America on the Uruguayan coast (∼35S) and downshelf from the Rio de la Plata estuary. Our observations show that the buoyancy-driven subtidal alongshore circulation is modulated by winds. During the winter, strong upwelling-favorable local winds forced the Rio de la Plata buoyant plume poleward. In the summer, the plume detached from the coast with warm and saline subtropical waters intruding from the north. These waters bounded the upwelling of cold waters in the nearshore area off Uruguay. A shallow submarine canyon cutting obliquely across the shelf facilitates …

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Seasonal Dynamics Of The Depth And Rate Of Anaerobic Oxidation Of Methane In Aarhus Bay (Denmark) Sediments, A. W. Dale, D. R. Aguilera, P. Regnier, H. Fossing, N. J. Knab, B. B. Jørgensen Jan 2008

Seasonal Dynamics Of The Depth And Rate Of Anaerobic Oxidation Of Methane In Aarhus Bay (Denmark) Sediments, A. W. Dale, D. R. Aguilera, P. Regnier, H. Fossing, N. J. Knab, B. B. Jørgensen

Journal of Marine Research

A reactive-transport model has been applied to investigate the dynamics of the sulfate-methane transition zone (SMTZ) in nearshore sediments of Aarhus Bay (Denmark). The sediments are influenced by seasonal variations of temperature and particulate organic carbon (POC) deposition flux at the sediment-water interface. Initially, the model was calibrated at steady state using field data collected at two sites (M1 and M5) in December 2004, and included a dynamic gas phase which determines the depth of the SMTZ. Simulations were then performed under transient conditions of heat propagation in the porous medium, which influenced the solubility of gaseous methane, the diffusion …

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Transport Of Blue Crab Larvae In The Middle Atlantic Bight: A Wet And Windy Journey, Charles E. Epifanio, Charles E. Tilburg Jan 2008

Transport Of Blue Crab Larvae In The Middle Atlantic Bight: A Wet And Windy Journey, Charles E. Epifanio, Charles E. Tilburg

Journal of Marine Research

This paper describes the 25-year evolution of a program of research into the larval ecology of the Atlantic blue crab (Callinectes sapidus) near the mouth of Delaware Bay on the east coast of the USA (38.5N, 75.1W). The investigation began as a biological study; eventually incorporated a physical component; and finally added a mathematical modeling aspect. Early work was strictly biological and demonstrated that C. sapidus larvae are exported from the estuary to the adjacent coastal ocean where larval development occurs. Once this fact was established, it was clear that further progress demanded an understanding of shelf circulation. …

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A Mechanism For Establishment And Maintenance Of The Meridional Overturning In The Upper Ocean, Timour Radko Jan 2007

A Mechanism For Establishment And Maintenance Of The Meridional Overturning In The Upper Ocean, Timour Radko

Journal of Marine Research

A two-dimensional analytical residual-mean model of the meridional overturning in the upper ocean is presented which illustrates dynamics of the interaction between the Northern and Southern hemispheres. The theory is based on the semi-adiabatic approximation in which all diabatic processes are confined to the upper mixed layer. The overturning circulation is driven directly by the wind forcing which, in our model, is affected by the sea-surface temperature distribution. The surface boundary conditions are symmetric with respect to the equator, and therefore one of the steady state solutions represents a symmetric flow characterized by the absence of the inter-hemispheric buoyancy fluxes. …

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Equatorial Deep Jets Triggered By A Large Vertical Scale Variability Within The Western Boundary Layer, Marc D'Orgeville, Bach Lien Hua, Hideharu Sasaki Jan 2007

Equatorial Deep Jets Triggered By A Large Vertical Scale Variability Within The Western Boundary Layer, Marc D'Orgeville, Bach Lien Hua, Hideharu Sasaki

Journal of Marine Research

The response of the deep equatorial ocean to an oscillatory baroclinic western boundary current is investigated in a continuously stratified primitive equation model. The symmetry of the current about the equator is such that mixed Rossby-gravity (MRG) waves are excited in the western part of the equatorial ocean. Depending on the forcing frequency, short to long scale (when compared to equatorial Rossby radius) monochromatic MRG waves are selected. The subsequent MRG wave destabilization generally leads to a much higher vertical mode response than the forced MRG wave mode. In a channel, short MRG waves are destabilized by shear instability (Hua …

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Mean Jets, Mesoscale Variability And Eddy Momentum Fluxes In The Surface Layer Of The Antarctic Circumpolar Current In Drake Passage, Y. D. Lenn, T. K. Chereskin, J. Sprintall, E. Firing Jan 2007

Mean Jets, Mesoscale Variability And Eddy Momentum Fluxes In The Surface Layer Of The Antarctic Circumpolar Current In Drake Passage, Y. D. Lenn, T. K. Chereskin, J. Sprintall, E. Firing

Journal of Marine Research

High-resolution Acoustic Doppler Current Profiler (ADCP) observations of surface-layer velocities in Drake Passage, comprising 128 sections over a period of 5 years, are used to study the surface-layer circulation of the Antarctic Circumpolar Current (ACC). These observations resolve details of the mean flow including the topographic control of the mean Subantarctic Front (SAF) and the multiple filaments of the Polar Front (PF) and Southern ACC Front (SACCF) that converge into single mean jets as the ACC flows through Drake Passage. Subsurface definitions of the SAF and PF applied to expendable bathythermograph temperatures generally coincide with mean jets, while the SACCF …

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Plankton Accumulation And Transport In Propagating Nonlinear Internal Fronts, A. Scotti, J. Pineda Jan 2007

Plankton Accumulation And Transport In Propagating Nonlinear Internal Fronts, A. Scotti, J. Pineda

Journal of Marine Research

Accumulation and transport of plankton in fronts propagating across-shore is a process of considerable ecological importance for many inhabitants of the littoral zone, since it links the offshore larval pool with the juvenile and adult inshore habitat. Several field studies have shown that larval plankton accumulates in fronts, but have failed to give a conclusive proof that effective Lagrangian transport takes place. A few process-oriented numerical studies have lent support to the idea, but the scope of their results is limited by the two-dimensional nature of the flows considered and by the simple model used to account for the behavior …

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Near-Bottom Horizontal Transfer Of Particulate Matter In The Palamós Submarine Canyon (Nw Mediterranean), J. Martin, A. Palanques, P. Puig Jan 2007

Near-Bottom Horizontal Transfer Of Particulate Matter In The Palamós Submarine Canyon (Nw Mediterranean), J. Martin, A. Palanques, P. Puig

Journal of Marine Research

From March to November 2001, six current meters equipped with turbidimeters were moored 12 meters above the bottom inside the Palamós submarine canyon and on the adjacent slope. Horizontal particle fluxes were calculated from current and suspended sediment concentration data. This work aims to evaluate the advective sediment fluxes taking place in the Palamós canyon region, and to discern the nature and time-scales of the processes involved in the across-margin transfer of particles over the study period. Near-bottom currents inside the canyon were constrained by the local topography and displayed a high spatio-temporal variability. The net near-bottom transport of suspended …

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Simulations Of Phytoplankton Species And Carbon Production In The Equatorial Pacific Ocean 1. Model Configuration And Ecosystem Dynamics, Baris Salihoglu, Eileen E. Hofmann Jan 2007

Simulations Of Phytoplankton Species And Carbon Production In The Equatorial Pacific Ocean 1. Model Configuration And Ecosystem Dynamics, Baris Salihoglu, Eileen E. Hofmann

Journal of Marine Research

The primary objective of this research is to investigate phytoplankton community response to variations in physical forcing and biological processes in the Cold Tongue region of the equatorial Pacific Ocean at 0N, 140W. This research objective was addressed using a one-dimensional multicomponent lower trophic level ecosystem model that includes detailed algal physiology, such as spectrally-dependent photosynthetic processes and iron limitation on algal growth. The ecosystem model is forced by a one-year (1992) time series of spectrally-dependent light, temperature, and water column mixing obtained from a Tropical Atmosphere-Ocean (TAO) Array mooring. Autotrophic growth is represented by five algal groups, which have …

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Influence Of Environmental Forcings On The Seasonality Of Dissolved Oxygen And Nutrients In The Bay Of Bengal, S. Sardessai, N. Ramaiah, S. Prasanna Kumar, S. N. De Sousa Jan 2007

Influence Of Environmental Forcings On The Seasonality Of Dissolved Oxygen And Nutrients In The Bay Of Bengal, S. Sardessai, N. Ramaiah, S. Prasanna Kumar, S. N. De Sousa

Journal of Marine Research

Studies on seasonal variability of oxygen and nutrients during three seasons namely SW monsoon, fall intermonsoon and spring intermonsoon indicate influence of physical forcings on the distribution of these hydrochemical properties in the subsurface layer. In the open ocean the Minimum Oxygen Layer (MOL ≤10 mu Mol L-1) during the southwest monsoon and fall intermonsoon is mostly confined to the north of 11N due to the penetration of high salinity water in the deeper waters of the central Bay. During spring intermonsoon MOL is mostly confined to the northern region between 14 to 20N with a narrow band …

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A Fast Numerical Solution To The General Mass-Conservation Equation For Solutes And Solids In Aquatic Sediments, Peter Berg, Dennis Swaney, Søren Rysgaard, Bo Thamdrup, Henrik Fossing Jan 2007

A Fast Numerical Solution To The General Mass-Conservation Equation For Solutes And Solids In Aquatic Sediments, Peter Berg, Dennis Swaney, Søren Rysgaard, Bo Thamdrup, Henrik Fossing

Journal of Marine Research

Mathematical modeling of species transformations in aquatic sediments is usually based on numerical solutions to the same general one-dimensional mass-conservation equation and is likely to require substantial computation time. In this paper we present a fast numerical solution to this equation. The solution is suited for both single and multi-component models and it is based on an implicit control volume discretization of the general mass-conservation equation. The solution consists of two algorithms, one that decomposes the discretization matrix once and one that subsequently produces multiple solutions with minimal computational effort. A unique feature of these algorithms is that values of …

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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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