Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Institution
- Publication Year
- Publication
-
- Journal of Marine Research (2451)
- Marine Biology (24)
- Fisheries (16)
- Theses (Unassigned) (5)
- Master's Theses (4)
-
- Biological Sciences (3)
- Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions) (3)
- Graduate Theses, Dissertations, and Problem Reports (ETD) (2)
- Biological Sciences Faculty Publications (1)
- Honors Papers (1)
- Journal of Marine Science and Technology–Taiwan (1)
- Master's Theses and Capstones (1)
- OES Faculty Publications (1)
- Open Access Master's Theses (1)
- School of Biological and Marine Sciences Theses (1)
- Theses and Dissertations (1)
- Publication Type
- File Type
Articles 781 - 810 of 2516
Full-Text Articles in Entire DC Network
Parameterization Of Mesoscale Eddy Fluxes In Zonal Ocean Flows, Vladimir O. Ivchenko, Kelvin J. Richards, Bablu Sinha, Jörg-Olaf Wolff
Parameterization Of Mesoscale Eddy Fluxes In Zonal Ocean Flows, Vladimir O. Ivchenko, Kelvin J. Richards, Bablu Sinha, Jörg-Olaf Wolff
Journal of Marine Research
Quasi-geostrophic dynamics in an eddy-resolving zonal re-entrant channel in the Southern Hemisphere have been studied for east- and westward wind forcing scenarios. The main difference is seen in the zonally averaged velocity profiles. In the case of eastward forcing, transient eddies strongly intensify the flow in the channel center into a jet, a feature totally absent in the westward forcing cases. The free jet is associated with a five times higher available potential energy compared to the westward flow. We have used these two distinctly different flow regimes to investigate possible parameterizations of the eddy fluxes in both situations. Parameterizations …
Circulation Around Islands And Ridges, Joseph Pedlosky, Lawrence J. Pratt, Michael A. Spall, Karl R. Helfrich
Circulation Around Islands And Ridges, Joseph Pedlosky, Lawrence J. Pratt, Michael A. Spall, Karl R. Helfrich
Journal of Marine Research
The circulation in an ocean basin containing an island is studied under nearly geostrophic, beta plane dynamics. The model is a fluid of uniform density driven by wind forcing or sources and sinks of mass at the upper boundary of the flow. The circulation is studied analytically, numerically, as well as in the laboratory through the device of the “sliced cylinder” model for the ocean circulation. Of particular interest is the estimate of the transport between the island and the oceanic basin's boundary. The model is conceived as relevant to both the wind-driven circulation as well as the circulation of …
Influences Of River Discharge On Biological Production In The Inner Shelf: A Coupled Biological And Physical Model Of The Louisiana-Texas Shelf, Changsheng Chen, Denis A. Wiesenburg, Liusen Xie
Influences Of River Discharge On Biological Production In The Inner Shelf: A Coupled Biological And Physical Model Of The Louisiana-Texas Shelf, Changsheng Chen, Denis A. Wiesenburg, Liusen Xie
Journal of Marine Research
A coupled biological and physical model was applied to study the influence of river discharge on biological variability on the Louisiana-Texas (LATEX) continental shelf. The physical part included a primitive-equation turbulent closure model, and the biological part was a simple phytoplankton (P), zooplankton (Z), and nutrient (N) model. The model was forced by freshwater discharge from the river and ran prognostically under initial conditions of springtime water stratification and a steady-state solution of the P-Z-N model with no horizontal dependence. A nutrient source was included at the mouth of the river. The model predicted …
Subduction Of Water Masses In An Eddying Ocean, David Marshall
Subduction Of Water Masses In An Eddying Ocean, David Marshall
Journal of Marine Research
Mesoscale eddies modify the rate at which a water mass transfers from the surface mixed layer of the ocean into the interior thermocline, in particular in regions of intense baroclinic instability such as the Antarctic Circumpolar Current, open-ocean convective chimneys, and ocean fronts. Here, the time-mean subduction of a water mass, evaluated following the meandering surface density outcrops, is found to incorporate a rectified contribution from eddies, arising from correlations between the area over which the water mass is outcropped at the sea surface and the local subduction rate. Alternatively, this eddy subduction can be interpreted in terms of an …
Transient Hydrographic And Chemical Conditions Affecting Microplankton Populations In The Coastal Transition Zone Of The Iberian Upwelling System (Nw Spain) In September 1986, C. G. Castro, X. A. Alvarez-Salgado, F. G. Figueiras, F. F. Perez, F. Fraga
Transient Hydrographic And Chemical Conditions Affecting Microplankton Populations In The Coastal Transition Zone Of The Iberian Upwelling System (Nw Spain) In September 1986, C. G. Castro, X. A. Alvarez-Salgado, F. G. Figueiras, F. F. Perez, F. Fraga
Journal of Marine Research
The coastal transition zone and adjacent continental shelf of the Iberian upwelling system was studied in September 1986, during the seasonal transition from upwelling-favored to downwelling-favored winds. The most striking features in the coastal transition zone were: (1) a poleward flow of high salinity Eastern North Atlantic Central Water (subtropical) off the Rías Baixas (Galician western coast); and (2) an anticyclonic eddy off Cape Ortegal (Galician northern coast). Chemical and biological similarities between both structures, clearly different from the surrounding oceanic waters, suggest that the eddy was an isolated and aged parcel of water originating from the poleward flow. The …
Long-Term Measurements Of Flow Near The Aleutian Islands, R. K. Reed, P. J. Stabeno
Long-Term Measurements Of Flow Near The Aleutian Islands, R. K. Reed, P. J. Stabeno
Journal of Marine Research
In summer 1995, the Alaskan Stream at 173.5W was very intense; the peak geostrophic speed was ≈125 cm s−1, and the computed volume transport above 1000 db, referred to 1000 db, was 9 × 106 m3 s−1). Flow north of the central Aleutians was shallow, convoluted and weak (2– 3 × 106 m3 s−1). A sequence of CTD casts across Amukta Pass, spaced irregularly in time during 1993–1996, showed a mean northward (southward) geostrophic transport of 1.0 (0.4) × 106 m3 s−1, for a net flow …
Large-Scale Circulation With Small Diapycnal Diffusion: The Two-Thermocline Limit, R. M. Samelson, Geoffrey K. Vallis
Large-Scale Circulation With Small Diapycnal Diffusion: The Two-Thermocline Limit, R. M. Samelson, Geoffrey K. Vallis
Journal of Marine Research
The structure and dynamics of the large-scale circulation of a single-hemisphere, closed-basin ocean with small diapycnal diffusion are studied by numerical and analytical methods. The investigation is motivated in part by recent differing theoretical descriptions of the dynamics that control the stratification of the upper ocean, and in part by recent observational evidence that diapycnal diffusivities due to small-scale turbulence in the ocean thermocline are small (≈0.1 cm2 s−1). Numerical solutions of a computationally efficient, three-dimensional, planetary geostrophic ocean circulation model are obtained in a square basin on a mid-latitude β-plane. The forcing consists of a zonal …
Time-Dependent Motions And The Nonlinear Bottom Ekman Layer, K. H. Brink
Time-Dependent Motions And The Nonlinear Bottom Ekman Layer, K. H. Brink
Journal of Marine Research
The laminar bottom Ekman layer beneath a flow with finite relative vorticity is studied. First, the case with only a steady interior shear flow is reviewed, and then a case with a spatially uniform oscillating flow is superimposed. In both cases, the problem can be reduced to solving ordinary differential equations. The competition of two effects governs the results. The interior vorticity effectively modifies the rotation rate, but advection (especially vertically, due to Ekman pumping) tends to counteract the vorticity modification. Vertical advection keeps the time-dependent boundary layer well behaved for negative interior vorticities, but a boundary layer singularity can …
On The Differences Between Bubble-Mediated Air-Water Transfer In Freshwater And Seawater, W. E. Asher, L. M. Karle, B. J. Higgins
On The Differences Between Bubble-Mediated Air-Water Transfer In Freshwater And Seawater, W. E. Asher, L. M. Karle, B. J. Higgins
Journal of Marine Research
Bubble populations and gas transfer velocities were measured in cleaned and surfactant-influenced freshwater and seawater. A nonlinear fitting technique was used to partition the total gas transfer velocity for a gas in each water type into a turbulence- and bubble-mediated fraction. This showed that the bubble-mediated transfer fraction was larger in cleaned freshwater than in cleaned seawater and that the difference was a function of diffusivity and solubility. This was explained by the fact that the bubble measurements showed that bubble plumes in cleaned freshwater had a higher concentration of large bubbles and a lower concentration of small bubbles than …
Instability In Stratified Rotating Shear Flow Along Ridges, G. A. Schmidt, E. R. Johnson
Instability In Stratified Rotating Shear Flow Along Ridges, G. A. Schmidt, E. R. Johnson
Journal of Marine Research
This paper examines the interaction between continuously stratified horizontal shear flow and topography. It investigates when topography whose slope changes sign (i.e., a ridge or a trench) destabilizes a shear flow. The instabilities have the form of topographic Rossby waves and rely on the background potential vorticity gradient to exist. Barotropic flow is examined in detail for general horizontal shear over stepped topography and the longwave stratified case is examined in the more specific case of linear shear flow over a top-hat ridge profile. In all cases modes are unstable over significant ranges of the relevant parameters. Stationary unstable modes …
A Laboratory Study Of The Effects Of A Sloping Side Boundary On Wind-Driven Circulation In A Homogeneous Ocean Model, Ross W. Griffiths, George Veronis
A Laboratory Study Of The Effects Of A Sloping Side Boundary On Wind-Driven Circulation In A Homogeneous Ocean Model, Ross W. Griffiths, George Veronis
Journal of Marine Research
A laboratory model is used to investigate the effects of sloping boundaries on homogeneous wind-driven β-plane circulation. The very gentle slopes of real oceanic boundaries raise the possibility that dissipation by lateral diffusion of vorticity to the boundary is largely removed, leaving dissipation only in bottom Ekman layers. The laboratory model is a modification of the rotating ‘sliced-cylinder’ introduced by Pedlosky and Greenspan (1967) and Beardsley (1969) and in which flow is driven by a differentially rotating lid. The vertical wall is replaced with a side wall having a uniform 45° slope around the entire perimeter. This sloping boundary, like …
On The Transition Between Different Dynamical Regimes Of The Antarctic Circumpolar Current, V. M. Kamenkovich
On The Transition Between Different Dynamical Regimes Of The Antarctic Circumpolar Current, V. M. Kamenkovich
Journal of Marine Research
Two different dynamical regimes of the Antarctic Circumpolar Current are considered: the Sverdrup regime and the frictionally controlled one. In the former the intensity of the current does not depend on friction, while in the latter it is inversely proportional to the coefficient of friction. The transition between these two regimes is studied. It is shown that the frictionally controlled regime is generated not only in the case of closed isolines of ambient potential vorticity q. The regime is formed in the case of blocked (or partially blocked) q isolines as well, if the slope of the q isolines …
Monitoring The Upper Southeastern Atlantic Transports Using Altimeter Data, Silvia L. Garzoli, Gustavo J. Goñi, Arthur J. Mariano, Donald B. Olson
Monitoring The Upper Southeastern Atlantic Transports Using Altimeter Data, Silvia L. Garzoli, Gustavo J. Goñi, Arthur J. Mariano, Donald B. Olson
Journal of Marine Research
A large in-situ data set, collected in the southeastern Atlantic Ocean, is merged with the TOPEX/POSEIDON altimeter observations in order to verify the use of altimeter data in monitoring the transports of the Agulhas/Benguela system. Comparisons between altimeter observations and either moored current meters or inverted echo sounder measurements shows that the sea-surface elevation anomaly is significantly correlated with the thermocline depth and the surface dynamic height, respectively. Knowing the least-squares regression parameters, it is possible to calculate the transports by using geostrophy and either a two-layer or a continuously-stratified model. The transports obtained from fits of dynamic height to …
Barotropic, Wind-Driven Circulation In A Small Basin, S. P. Meacham, P. S. Berloff
Barotropic, Wind-Driven Circulation In A Small Basin, S. P. Meacham, P. S. Berloff
Journal of Marine Research
We study the asymptotic behavior (large time) of a simple, wind-driven, barotropic ocean model, described by a nonlinear partial differential equation with two spatial dimensions. Considered as a dynamical system, this model has an infinite-dimensional phase space. After discretization, the equivalent numerical model has a phase space of finite but large dimension. We find that for a considerable range of friction, the asymptotic states are low-dimensional attractors. We describe the changes in the structure of these asymptotic attractors as a function of the eddy viscosity of the model. A variety of different types of attractor are seen, with chaotic attractors …
The Hydrography And Circulation Of The Upper 1200 Meters In The Tropical North Atlantic During 1982-91, Gennady Chepurin, James A. Carton
The Hydrography And Circulation Of The Upper 1200 Meters In The Tropical North Atlantic During 1982-91, Gennady Chepurin, James A. Carton
Journal of Marine Research
We assemble a collection of 7591 conductivity-temperature-depth stations in the tropical Atlantic between 5S and 20N for the period 1982–1991 using data from the Soviet SECTIONS program enhanced by contributions primarily from the WESTRAX and FOCAL/SEQUAL programs. Most of the stations are west of 30W, forming a series of 21 surveys. In addition there were five multi-ship basinwide surveys, each taking 1.5–3 months to complete. The quality of the SECTIONS data is discussed and comparisons between the data sets are shown. Within the pycnocline, southern water is distinguished by salinity that is 0.3 psu lower than its northern counterpart at …
Updated Bathymetry Of The Anegada-Jungfern Passage Complex And Implications For Atlantic Inflow To The Abyssal Caribbean Sea, David M. Fratantoni, Rainer J. Zantopp, William E. Johns, Jerry L. Miller
Updated Bathymetry Of The Anegada-Jungfern Passage Complex And Implications For Atlantic Inflow To The Abyssal Caribbean Sea, David M. Fratantoni, Rainer J. Zantopp, William E. Johns, Jerry L. Miller
Journal of Marine Research
Recent bathymetric, hydrographic and direct velocity measurements indicate that a previously unexplored deep passage in the northeastern Caribbean Sea may play a significant role in the abyssal ventilation of this basin. The Anegada-Jungfern Passage complex has long been recognized as the sole pathway for deep Atlantic inflow to the eastern Caribbean. The Anegada Passage (sill depth 1915 m) connects the Atlantic Ocean with the small Virgin Islands Basin, while Jungfern Passage (sill depth 1815 m) connects the latter with the large and deep Venezuela Basin comprising the eastern third of the Caribbean Sea. In the region of Jungfern Passage recent …
Implications Of The Salt And Heat Budgets Of The Gulf Of Thailand, Kate Stansfield, Chris Garrett
Implications Of The Salt And Heat Budgets Of The Gulf Of Thailand, Kate Stansfield, Chris Garrett
Journal of Marine Research
Hydrographic data collected during 1959 and 1960 in the Gulf of Thailand, combined with supporting climatological data, have been used to investigate the salt and heat budgets of the Gulf. A simple model including mixing, net precipitation, local river run-off and Ekman flux predicts the flushing time of the Gulf, associated with processes other than the Ekman flux, to be 12.0 months, but predicts too small a magnitude and the wrong phase for the observed seasonal salinity cycle. Adding the discharge from the Mekong River reduces the flushing time to 5.4 months and improves the fit to the magnitude of …
Morphological And Compositional Evidence For Biotic Precipitation Of Marine Barite, Miriam A. Bertram, James P. Cowen
Morphological And Compositional Evidence For Biotic Precipitation Of Marine Barite, Miriam A. Bertram, James P. Cowen
Journal of Marine Research
Barite formation in the surface oceans is generally assumed to be dominated by abiotic precipitation. Acceptance of this pathway is largely the result of the absence of a pelagic marine organism known to precipitate the ovoid to rounded-rectangular barite crystals typically observed in marine waters and sediments. Barite crystals observed in net-tow particles and on substrates retrieved from the seafloor (both in the central North Pacific) were examined by scanning electron microscopy and energy dispersive X-ray spectrometry. Three distinct crystalline forms of barite were observed: ovoid and hexagonal crystals several microns in diameter, and aggregates of submicron-sized crystals. Ovoid and …
Sediment Resuspension Rates, Organic Matter Quality And Food Utilization By Sea Scallops (Placopecten Magellanicus) On Georges Bank, Jonathan Grant, Peter Cranford, Craig Emerson
Sediment Resuspension Rates, Organic Matter Quality And Food Utilization By Sea Scallops (Placopecten Magellanicus) On Georges Bank, Jonathan Grant, Peter Cranford, Craig Emerson
Journal of Marine Research
Benthic detritus, bacteria, and settled phytoplankton are transported into the water column by resuspension, potentially providing a high quality food source to suspension feeders. Two aspects of resuspension must be considered in relation to food supplies for suspension feeders: the flux of particles from the sediments to the water column and its food value. Sediment resuspension rates on Georges Bank and the role of resuspended sediment in the diet of sea scallops (Placopecten magellanicus) were determined in laboratory flume experiments and shipboard feeding experiments, respectively. Resuspended carbon flux was estimated from flume bedload transport rates and the mass …
Dynamics Of A Migratory Fish Population With Applications To The Management Of Sablefish In The Northeast Pacific Ocean, Jonathan Heifetz
Dynamics Of A Migratory Fish Population With Applications To The Management Of Sablefish In The Northeast Pacific Ocean, Jonathan Heifetz
Fisheries
Quantitative models are developed to describe the dynamics of an age-structured migratory fish population subject to exploitation. Migration rates are quantified, alternative ways of apportioning harvest among areas are examined, and the dynamics of a migratory population is described within the general theoretical framework of a projection matrix model. Application of these modeling efforts is within the context of the sablefish (Anoplopoma fimbria) fishery in the North Pacific Ocean. A Markov model that includes natural and fishing mortality, tag reporting and shedding rates, and migration is used to quantify migration rates of tagged sablefish among fishery regulatory areas. Estimates of …
The Red King Crab Fishery: Handling Effects, Bait Efficiency, And Pot Behavior, Shijie Zhou
The Red King Crab Fishery: Handling Effects, Bait Efficiency, And Pot Behavior, Shijie Zhou
Fisheries
Red king crabs (Paralithodes camtschaticus) are caught by pots in a male-only fishery in Alaska. The objectives of this research were: (1) to examine impacts of the commercial fishery on discarded female and sublegal male crabs; (2) to examine bait efficiency; (3) to document crab behavior to pots; and (4) to develop a model describing catch versus soak time. I estimated from observer data that 64.6% of crabs in the Bering Sea fishery were females and sublegal males; I simulated commercial crab handling procedures in the laboratory to test effects on discarded crabs. Although body damage increased significantly with increased …
Distinct Year-To-Year Particle Flux Variations Off Cape Blanc During 1988-1991: Relation To Δ 18o-Deduced Sea-Surface Temperatures And Trade Winds, G. Fischer, B. Donner, V. Ratmeyer, R. Davenport, G. Wefer
Distinct Year-To-Year Particle Flux Variations Off Cape Blanc During 1988-1991: Relation To Δ 18o-Deduced Sea-Surface Temperatures And Trade Winds, G. Fischer, B. Donner, V. Ratmeyer, R. Davenport, G. Wefer
Journal of Marine Research
Particle fluxes measured from 1988 to 1991 adjacent to a coastal upwelling site off Cape Blanc showed significant interannual variability of fluxes and sea-surface temperatures (SST) deduced from stable oxygen isotope analysis of the planktonic foraminifera Globigerinoides ruber and, partly, of the pteropod Limacina inflata. For the duration of the study period, a decrease in the seasonality of SST's was observed, as well as a significant decrease in the average annual SST from 24.4° to 20.8°C. This cooling trend was mainly the effect of a drastic decrease in the summer to fall SST (from 27.2° to 21.8°C). In comparison, …
The Role Of Mesoscale Hydrography On Microbial Dynamics In The Northeast Atlantic: Results Of A Spring Bloom Experiment, B. Karrasch, H. G. Hoppe, S. Ullrich, S. Podewski
The Role Of Mesoscale Hydrography On Microbial Dynamics In The Northeast Atlantic: Results Of A Spring Bloom Experiment, B. Karrasch, H. G. Hoppe, S. Ullrich, S. Podewski
Journal of Marine Research
During RV Meteor cruise No. 10 from May to June 1989 (JGOFS pilot study) bacterial and picocyanobacterial abundance, biomass, and bacterial production were estimated at two drift stations close to 47N, 20W and 58N, 20W in the northeast Atlantic. At 47N two different mesoscale hydrographic structures were sampled which divided the drift experiment into a cyclonic and an anticyclonic circulation phase. Transition from one phase to the next was clearly reflected by changes of the biological structure in the upper water column. Phytoplankton stocks maintained during the cyclonic phase were about 1.8 times higher than those of the anticyclonic phase …
Biological Removal Of Fine-Grained Lithogenic Particles From A Large River Plume, M. J. Dagg, E. P. Green, B. A. Mckee, P. B. Ortner
Biological Removal Of Fine-Grained Lithogenic Particles From A Large River Plume, M. J. Dagg, E. P. Green, B. A. Mckee, P. B. Ortner
Journal of Marine Research
The pelagic tunicate, Oikopleura dioica, feeds by non-selectively filtering particles in the size range of 0.2–20 μm. In the northern Gulf of Mexico, particulate matter in this size range contains large amounts of fine-grained lithogenic material because of the influence of the Mississippi River. During May 1992, O. dioica populations filtered between 2 and 44% (mean = 20%) of the upper 5 m each day. The filtered lithogenic particles either remain in the oikopleurid house or are defecated in fecal pellets which have high sinking velocities. Either way, the larvacean populations significantly alter the fates of fine-grained lithogenic particles …
Molecular Diversity Of The Copepod, Nannocalunus Minor: Genetic Evidence Of Species And Population Structure In The North Atlantic Ocean, Anna Bucklin, Todd C. Lajeunesse, Eva Curry, John Wallinga, Karen Garrison
Molecular Diversity Of The Copepod, Nannocalunus Minor: Genetic Evidence Of Species And Population Structure In The North Atlantic Ocean, Anna Bucklin, Todd C. Lajeunesse, Eva Curry, John Wallinga, Karen Garrison
Journal of Marine Research
The abundant calanoid copepod, Nannocalanus minor, is widespread from the Florida Straits (FS), throughout the Gulf Stream and the Sargasso Sea, to the eastern North Atlantic Ocean. Does the species represent a single, randomly-mating population across this extensive region, or does it comprise a number of genetically distinct populations or taxonomically distinct forms? What are patterns and pathways of dispersal of the copepod across the North Atlantic? These questions were addressed using population genetic analysis of DNA sequence variation of a 440 base-pair region of the mitochondrial 16S rRNA gene. This analysis separated N. minor into two genetically distinct …
A High Resolution Camera System (Parca) For Imaging Particles In The Ocean: System Design And Results From Profiles And A Three-Month Deployment, Volker Ratmeyer, Gerold Wefer
A High Resolution Camera System (Parca) For Imaging Particles In The Ocean: System Design And Results From Profiles And A Three-Month Deployment, Volker Ratmeyer, Gerold Wefer
Journal of Marine Research
For direct optical measurement of abundance, concentration and size distribution of marine particles, a high-resolution camera system (ParCa) was designed to improve on similar systems used by Honjo et al. (1984), Asper (1987) and others. Imaging a probe volume of up to 37 1, smallest particles with diameters of 50 μm can be counted. The images provide information on particle size, shape and abundance either during profiling through the water column or while moored in a certain depth over time. Depth profiles were acquired between fall 1992 and late spring 1993 on R. V. Meteor cruises M22-1 and M23-3 …
Seasonal Transport Variations Of The Wind-Driven Ocean Circulation In A Two-Layer Planetary Geostrophic Model With A Continental Slope, Toshihiro Sakamoto, Toshio Yamagata
Seasonal Transport Variations Of The Wind-Driven Ocean Circulation In A Two-Layer Planetary Geostrophic Model With A Continental Slope, Toshihiro Sakamoto, Toshio Yamagata
Journal of Marine Research
Using a simple two-layer planetary geostrophic model with a continental slope, the observed seasonal variation of the total transport of the Kuroshio is explained qualitatively for the first time in a quite concise way. During the period of weak winds in summer, the total transport is much larger than the nontopographic Sverdrup transport. This is because the joint effect of baroclinicity and bottom relief (so-called JEBAR) drives the barotropic flow with releasing the available potential energy accumulated in winter. In winter, on the other hand, the transport is much smaller than the nontopographic Sverdrup transport. This is mainly due to …
Carbon Cycling In Mesohaline Chesapeake Bay Sediments 2: Kinetics Of Particulate And Dissolved Organic Carbon Turnover, Eric E. Roden, Jon H. Tuttle
Carbon Cycling In Mesohaline Chesapeake Bay Sediments 2: Kinetics Of Particulate And Dissolved Organic Carbon Turnover, Eric E. Roden, Jon H. Tuttle
Journal of Marine Research
Temporal and depth variations in benthic carbon metabolism rates were examined in relation to particulate organic carbon (POC) deposition rates and particulate and dissolved organic carbon degradation kinetics in two sediments from the mesohaline region of Chesapeake Bay. The depth distribution of a single pool of metabolizable POC (MPOC) in mid-Bay sediments was estimated by curve-fitting of dry weight POC profiles (“1-G” approach). Estimated MPOC pools accounted for 3–4% of total POC content in the upper 10 cm of sediment. First-order MPOC decay constants of ≈10 yr−1 during the warm season were estimated from the ratio of …
The Role Of Turbulence In The Sedimentation Loss Of Pelagic Aggregates From The Mixed Layer, Javier Ruiz
The Role Of Turbulence In The Sedimentation Loss Of Pelagic Aggregates From The Mixed Layer, Javier Ruiz
Journal of Marine Research
A simple approach is presented to model the effect that turbulence has on the sedimentation loss of pelagic particles from the mixed layer. The approach consists in determining how turbulence affects their vertical distribution by splitting the solution of the advection-diffusion equation into two functions, one for the concentration of particles in the mixed layer and the other one reflecting the shape of the profile of particle concentration. The results of the paper indicate that the sedimentation flux is seriously underestimated if a uniform distribution of particles is assumed in the mixed layer when turbulence levels are low. A correction …
Grid-Scale Instability Of Convective-Adjustment Schemes, Paola Cessi
Grid-Scale Instability Of Convective-Adjustment Schemes, Paola Cessi
Journal of Marine Research
Through a simple illustrative example, it is shown that instantaneous convective adjustment schemes, of the type used in general circulation models to parametrize nonhydrostatic convective processes, lead to the spontaneous emergence of the smallest resolved horizontal scale: the grid mode is unstable regardless of the strength of the horizontal diffusivity. Convective adjustment vertically mixes properties at each grid-point, irrespective of the horizontal distribution of such properties. Thus, horizontal spatial gradients are amplified by convective adjustment, as long as adjustment is faster than the horizontal diffusion (or advection) time between neighboring grid-points. In the example presented here, the grid-scale instability is …