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 421 - 450 of 2516
Full-Text Articles in Entire DC Network
Simulation And Energy Partition Of The Flow Through Paso Galvarino, Chile, Michael W. Stacey, Arnoldo Valle-Levinson
Simulation And Energy Partition Of The Flow Through Paso Galvarino, Chile, Michael W. Stacey, Arnoldo Valle-Levinson
Journal of Marine Research
Paso Galvarino is a constriction in Seno Ventisquero, a tidally-energetic Chilean fjord. The pass is about 1500 m long and constricts in width by about 90 % near its sill, which has a depth of about 8 m. A laterally-averaged numerical model is compared to ADCP and backscatter observations of the hydraulic flow near the sill, during maximum flood, the slack tide after the flood, maximum ebb, and the slack tide after the ebb. The model is also used to examine how the energy flux into the fjord is partitioned in the region of the constriction. Energy is removed from …
The Evolution Of Density Currents And Nepheloid Bottom Layers In The Ross Sea (Antarctica), Giorgio Budillon, Ettore Salusti, Sergio Tucci
The Evolution Of Density Currents And Nepheloid Bottom Layers In The Ross Sea (Antarctica), Giorgio Budillon, Ettore Salusti, Sergio Tucci
Journal of Marine Research
In this study we have analyzed the thermohaline, light transmission and particulate matter data, obtained in the western sector of the Ross Sea during the X Italian Expedition, for the purpose of investigating the evolution of the High Salinity Shelf Water in this area. In particular CTD data were used to estimate the baroclinic velocity field. Light transmission and total particulate matter data (from Niskin bottles mounted on a Carousel water sampler) were used to analyze the nepheloid layers and the evolution of the suspended sediments. This basin is characterized by a northward flow of very dense High Salinity Shelf …
Sensitivity Of The Meridional Transport In A 1.5-Layer Ocean Model To Localized Mass Sources, C. Herbaut, J. Sirven, J. Deshayes
Sensitivity Of The Meridional Transport In A 1.5-Layer Ocean Model To Localized Mass Sources, C. Herbaut, J. Sirven, J. Deshayes
Journal of Marine Research
The response of a 1.5-layer ocean model forced by localized stochastic mass sources is studied. The focus is on the sensitivity of the spectral characteristics of the meridional transport to the location and the extent of the source region. In all the experiments, performed in hemispheric and interhemispheric basins, the spectra show a peak at interannual time scale revealing the existence of an oscillation. The period of the oscillation is defined by the zonal extent of the forcing, whereas its amplitude is affected by its location. When the source region is located in the northwestern corner of the basin, the …
Variability In The Indian Ocean Circulation And Salinity And Its Impact On Sst Anomalies During Dipole Events, Bijoy Thompson, C. Gnanaseelan, P. S. Salvekar
Variability In The Indian Ocean Circulation And Salinity And Its Impact On Sst Anomalies During Dipole Events, Bijoy Thompson, C. Gnanaseelan, P. S. Salvekar
Journal of Marine Research
The GFDL Modular Ocean Model (MOM4) has been used to understand the variability of the Indian Ocean circulation and salinity during Indian Ocean Dipole events. The model simulations are compared with HadISST, SODA and ECCO data sets. During the positive dipole years, the climatological cyclonic circulation in the Bay of Bengal weakens or is replaced by an anticyclonic circulation. The interannual variability in the Wyrtki Jet and Bay of Bengal circulation has significant influence on fresh water transport between the equatorial Indian Ocean and Bay of Bengal. The salinity anomalies in the equatorial Indian Ocean are significant during the positive …
Critical Effects Of A Tall Seamount On A Drifting Vortex, Georgi G. Sutyrin
Critical Effects Of A Tall Seamount On A Drifting Vortex, Georgi G. Sutyrin
Journal of Marine Research
The initial-value problem for the evolution of an isolated vortex encountering a tall seamount during its westward beta-drift is studied within an equivalent-barotropic model, that is generalized to allow for the intersection of the layer interface with a sloping bottom. Given the Rossby radius and linear wave speed in the model, the parabolic shape of a seamount top and initial potential vorticity profile in the vortex core, the outcome is controlled by the vortex sign and a number of parameters: the seamount radius and height of penetration into the active layer, the radius and intensity of the vortex, the initial …
Identifiability And Uncertainty Analysis Of Bio-Irrigation Rates, Johan H. Andersson, Jack J. Middelburg, Karline Soetaert
Identifiability And Uncertainty Analysis Of Bio-Irrigation Rates, Johan H. Andersson, Jack J. Middelburg, Karline Soetaert
Journal of Marine Research
Bio-irrigation is often quantified through incubations where an inert tracer is added to the overlying water of a core or a benthic chamber, and subsequently following the tracer distribution in either the overlying water or the porewater. The interpretation is based on fitting data with a model containing several unknown parameters such as the enhancement over molecular diffusion or non-local exchange. In this paper, we test under what conditions the results obtained through this fitting are robust. We first use identifiability analysis to investigate the minimum data requirements for two types of sediments, representative for deep-sea and shallow-water settings. We …
Cluster Analysis For Physical Oceanographic Data And Oceanographic Surveys In Turkish Seas, Derya Birant, Alp Kut
Cluster Analysis For Physical Oceanographic Data And Oceanographic Surveys In Turkish Seas, Derya Birant, Alp Kut
Journal of Marine Research
Cluster analysis is a useful data mining method to obtain detailed information on the physical state of the ocean. The primary objective of this study is the development of a new spatio-temporal density-based algorithm for clustering physical oceanographic data. This study extends the regular spatial cluster analysis to deal with spatial data at different epochs. It also presents the sensitivity of the new algorithm to different parameter settings. The purpose of the sensitivity analysis presented in this paper is to identify the response of the algorithm to variations in input parameter values and boundary conditions. In order to demonstrate the …
Variability Of The Subantarctic And Polar Fronts In The Drake Passage As Deduced From Altimetry, Nadine Chouaib, Felix Stoehr, Christine Provost
Variability Of The Subantarctic And Polar Fronts In The Drake Passage As Deduced From Altimetry, Nadine Chouaib, Felix Stoehr, Christine Provost
Journal of Marine Research
The magnitude and time variability of the total volume transport of the Antarctic Circumpolar Current through Drake Passage is a key climatic index, yet still uncertain. We processed ten years of TOPEX/Poseïdon data along two adjacent descending tracks in Drake Passage assuming (following Gille, 1994) that the surface current velocity has a profile structure of double Gaussian jets corresponding respectively to the Subantarctic Front (SAF) and the Polar Front (PF). We seek the location, width and intensity of each jet as a function of time. Results from the two tracks are coherent and show that the time evolution of the …
Nutrient Dynamics In The Northern Gulf Of Alaska And Prince William Sound: 1998--2001, Amy Ruehs Childers
Nutrient Dynamics In The Northern Gulf Of Alaska And Prince William Sound: 1998--2001, Amy Ruehs Childers
Marine Biology
The northern Gulf of Alaska (GOA) shelf is a productive coastal region that supports several commercially important fisheries. The mechanisms supporting such high levels of productivity over this shelf are not understood, however, since it is a downwelling-dominated shelf. In an effort to understand the mechanisms underlying such high biological productivity, nutrient distributions were determined 25 times throughout 1998, 1999, 2000, and 2001 from over the northern GOA shelf and in Prince William Sound (PWS). Deep water (>75 m) nitrate, silicate and phosphate concentrations were positively correlated with salinity indicating an offshore nutrient source. The average annual cycle was …
Current Primary Production Rates Of The Western Arctic Ocean Estimated By Stable Carbon And Nitrogen Isotope Tracers, Sang Heon Lee
Current Primary Production Rates Of The Western Arctic Ocean Estimated By Stable Carbon And Nitrogen Isotope Tracers, Sang Heon Lee
Marine Biology
Currently, the environments in the Arctic are rapidly changing. These changes of climate and ice conditions may alter the quantity, quality, and timing of production of ice algae and phytoplankton in the Arctic Ocean. The objectives in this study were to detect any change in the carbon production between current and previous studies and lay the groundwork for the future monitoring of ecosystem response to climate change in the different regions of the western Arctic Ocean. As an Arctic ocean mostly covered by multi or first-year ice, the deep Canada Basin had generally low photosynthetic rates and the maximum rates …
A Tribute To Nick Fofonoff, Sears Foundation Of Marine Research Yale University
A Tribute To Nick Fofonoff, Sears Foundation Of Marine Research Yale University
Journal of Marine Research
Biographical Notes: Nick Fofonoff
Bibliography: Nicholas Paul Fofonoff, Sears Foundation Of Marine Research Yale University
Bibliography: Nicholas Paul Fofonoff, Sears Foundation Of Marine Research Yale University
Journal of Marine Research
1953 Fofonoff, N. P. A theoretical example of wind-induced circulation in a semi-circular canal. Trans. Am. Geophys. Union, 34, 725-728.
Deep Ocean Experiments With Fossil Fuel Carbon Dioxide: Creation And Sensing Of A Controlled Plume At 4 Km Depth, Peter G. Brewer, Edward T. Peltzer, Peter Walz, Izuo Aya, Kenji Yamane, Ryuji Kojima, Yasuharu Nakajima, Noriko Nakayama, Peter Haugan, Truls Johannessen
Deep Ocean Experiments With Fossil Fuel Carbon Dioxide: Creation And Sensing Of A Controlled Plume At 4 Km Depth, Peter G. Brewer, Edward T. Peltzer, Peter Walz, Izuo Aya, Kenji Yamane, Ryuji Kojima, Yasuharu Nakajima, Noriko Nakayama, Peter Haugan, Truls Johannessen
Journal of Marine Research
The rapidly rising levels of atmospheric and oceanic CO2 from the burning of fossil fuels has lead to well-established international concerns over dangerous anthropogenic interference with climate. Disposal of captured fossil fuel CO2 either underground, or in the deep ocean, has been suggested as one means of ameliorating this problem. While the basic thermoladynamic properties of both CO2 and seawater are well known, the problem of interaction of the two fluids in motion to create a plume of high CO2/low pH seawater has been modeled, but not tested. We describe here a novel experiment designed …
On The World-Wide Circulation Of The Deep Water From The North Atlantic Ocean, Joseph L. Reid
On The World-Wide Circulation Of The Deep Water From The North Atlantic Ocean, Joseph L. Reid
Journal of Marine Research
Above the deeper waters of the North Atlantic that have entered from the circumpolar flow, convection in the Labrador Sea and overflow from the Mediterranean, Norwegian, and Greenland seas combine at mid-depth and circulate in the subarctic cyclonic gyre, and flow southward along the western boundary into the South Atlantic. Because of the nature of these sources the mid-depth waters of the North Atlantic are the warmest, most saline, highest in oxygen and lowest in silica of any of the mid-depth waters of the World Ocean. They have been called the North Atlantic Deep Water.In the Atlantic these characteristics have …
Available Potential Energy In The World’S Oceans, Rui Xin Huang
Available Potential Energy In The World’S Oceans, Rui Xin Huang
Journal of Marine Research
It is shown that in the case with bottom topography, the available gravitational potential energy cannot be represented by the available pressure potential energy. Thus, a suitable quantity for the study of large-scale circulation is the total available potential energy which is defined as the sum of available gravitational potential energy and available internal energy. A simple computational algorithm for calculating the available potential energy in the world's oceans is proposed and tested. This program includes the compressibility of seawater and realistic topography. It is estimated that the world's oceans available gravitational potential energy density is about 1474 J/m3 …
A Double-Diffusive Interface Tank For Dynamic-Response Studies, Raymond W. Schmitt, Robert C. Millard, John M. Toole, W. David Wellwood
A Double-Diffusive Interface Tank For Dynamic-Response Studies, Raymond W. Schmitt, Robert C. Millard, John M. Toole, W. David Wellwood
Journal of Marine Research
A large tank capable of long-term maintenance of a sharp temperature-salinity interface has been developed and applied to measurements of the dynamical response of oceanographic sensors. A two-layer salt-stratified system is heated from below and cooled from above to provide two convectively mixed layers with a thin double-diffusive interface separating them. A temperature jump exceeding 10°C can be maintained over 1–2 cm (a vertical temperature gradient of order 103°C/m) for several weeks. A variable speed-lowering system allows testing of the dynamic response of conductivity and temperature sensors in full-size oceanographic instruments. An acoustic echo sounder and shadowgraph system …
High-Pressure Thermodynamic Gibbs Functions Of Ice And Sea Ice, Rainer Fiestel, Wolfgang Wagner
High-Pressure Thermodynamic Gibbs Functions Of Ice And Sea Ice, Rainer Fiestel, Wolfgang Wagner
Journal of Marine Research
A new Gibbs thermodynamic potential function of ice Ih is proposed to extend and improve already existing ones and to unify various data and formulas for thermodynamic equilibrium properties of natural ice in a consistent manner. It is valid for absolute pressures from 0 to 211 MPa and for temperatures from 0 to 273.16 K. It is consistent with the current 1995 international scientific pure water standard, IAPWS-95, and with the latest 2003 Gibbs potential of seawater. In conjunction with the latter, it provides freezing temperatures of seawater for pressures up to 100 MPa (10,000 dbar). The potential functions of …
Basin-Scale Performance Of A Locally Optimized Marine Ecosystem Model, A. Oschlies, M. Schartau
Basin-Scale Performance Of A Locally Optimized Marine Ecosystem Model, A. Oschlies, M. Schartau
Journal of Marine Research
A marine ecosystem model, that had previously been calibrated in a one-dimensional (1D) mode against observations at three time-series and process-study sites simultaneously, is coupled to a three-dimensional (3D) circulation model of the North and Equatorial Atlantic. Compared to an experiment with a previously employed subjectively tuned ecosystem model, the new 3D-model does not only reduce the model-data misfit at those locations at which observations entered the 1D optimization procedure, but also at an oligotrophic site in the subtropics that had not been considered in the 1D calibration. Basin-scale gridded climatological data sets of nitrate, surface chlorophyll, and satellite-derived primary …
The Nonlocal Model Of Porewater Irrigation: Limits To Its Equivalence With A Cylinder Diffusion Model, Nicola J. Grigg, Bernard P. Boudreau, Ian T. Webster, Phillip W. Ford
The Nonlocal Model Of Porewater Irrigation: Limits To Its Equivalence With A Cylinder Diffusion Model, Nicola J. Grigg, Bernard P. Boudreau, Ian T. Webster, Phillip W. Ford
Journal of Marine Research
Burrows maintained by animals in aquatic sediments ventilate the sediment and can substantially alter the rates and pathways of biologically-mediated decomposition reactions. A well known and effective way of modeling the impact of such bioirrigation in sediment diagenetic models is to assume that solutes diffuse into an annulus of sediment surrounding the burrow; the reaction diffusion equations are represented in cylindrical polar co-ordinates. More commonly, bioirrigation of sediments is represented by one-dimensional "nonlocal" irrigation models. Their use is typically justified by the assertion that a nonlocal model is equivalent to a radially-integrated two-dimensional diffusion model in cylindrical-polar co-ordinates. In this …
Similar Rapid Response To Phytodetritus Deposition In Shallow And Deep-Sea Sediments, L. Moodley, J. J. Middelburg, K. Soetaert, H. T. S. Boschker, P. M. J. Herman, C. H. R. Heip
Similar Rapid Response To Phytodetritus Deposition In Shallow And Deep-Sea Sediments, L. Moodley, J. J. Middelburg, K. Soetaert, H. T. S. Boschker, P. M. J. Herman, C. H. R. Heip
Journal of Marine Research
The short-term benthic response to an input of fresh organic matter was examined in vastly contrasting benthic environments (estuarine intertidal to deep-sea) using 13C-labeled diatoms as a tracer of labile carbon. Benthic processing was assessed in major compartments through 13C-enrichment in σCO2, in bacteria-specific phospholipids and in fauna tissue. A rapid response was evident in all environments. Under warm bottom water (14–18°C), similar quantities of the added carbon were respired within 24 hours in shallow and deep-sea sediments. However, the speed and magnitude of respiration were strongly reduced under low bottom water temperature (4–6°C), both in …
On Rectification Of Randomly Forced Flows, Pavel S. Berloff
On Rectification Of Randomly Forced Flows, Pavel S. Berloff
Journal of Marine Research
Nonlinear rectification of the ocean circulation driven by random forcing, which simulates the effect of unresolved eddies, is studied in an idealized closed basin. The results are based on the analysis of randomly forced solutions and linear eigenmodes. Depending on the forcing strength, two rectification regimes are found: zonal jets and isolated gyres. It is shown that both regimes are due to nonlinear interactions of resonant basin modes. In the zonal-jet regime, these interactions involve complex interplay between resonant baroclinic modes and some secondary modes. Both Rhines' scaling for zonal jets and prediction of gyres based on the maximum entropy …
Dynamics Of A Co2-Seawater Interface In The Deep Ocean, Joakim Hove, Peter M. Haugan
Dynamics Of A Co2-Seawater Interface In The Deep Ocean, Joakim Hove, Peter M. Haugan
Journal of Marine Research
A trough filled with liquid CO2 located at 3940 m depth has been used as a model system for CO2 deposition on the seafloor. To study the intrinsic properties of the interface between CO2 and seawater a wave maker was used to excite regular plane waves. The frequency (≲2.5 rad/s) and wavelength (20 cm–40 cm) of the waves have been measured, and compare reasonably well with the dispersion relation for deep fluid gravity waves. The shear stability of the interface was investigated by setting the water above the CO2 in motion with a thruster. For shear …
Solute-Specific Pore Water Irrigation: Implications For Chemical Cycling In Early Diagenesis, Christof Meile, Peter Berg, Philippe Van Cappellen, Kagan Tuncay
Solute-Specific Pore Water Irrigation: Implications For Chemical Cycling In Early Diagenesis, Christof Meile, Peter Berg, Philippe Van Cappellen, Kagan Tuncay
Journal of Marine Research
In one-dimensional (1D) early diagenetic models, bioirrigation is typically represented by a nonlocal mass transfer or bioirrigation coefficient, α. Usually, all pore water species are assigned the same α. Here, we show that this assumption can lead to significant errors in estimates of bioirrigation intensities. Using a simplified early diagenetic reaction network, we compute the 3D concentration fields of major pore water species around a vertical burrow, as well as the solute fluxes across the burrow wall. From these results, corresponding 1D vertical α profiles are derived. The α profiles show pronounced differences from one solute to another. Dissolved O …
Effect Of Air-Sea Heat Exchange On Seasonal Transport Variation Of The Kuroshio, Toshihiro Sakamoto
Effect Of Air-Sea Heat Exchange On Seasonal Transport Variation Of The Kuroshio, Toshihiro Sakamoto
Journal of Marine Research
Observations up to the present indicate that the climatological volume transports of the Kuroshio have an annual range of at most 10 Sv and a maximum in summer, both of which are inconsistent with the nontopographic Sverdrup relation. We show that these observed properties may be reproduced using a two-layer planetary geostrophic model with variable bottom topography if we take into account sea-surface heat flux, as well as large interface displacements associated with layer outcropping. The thermal forcing is represented by seasonally changing the reduced gravity so that the available potential energy of the model ocean is decreased in winter …
Recent Interannual Upper Ocean Variability In The Deep Southeastern Bering Sea, Amy E. Wirts, Gregory C. Johnson
Recent Interannual Upper Ocean Variability In The Deep Southeastern Bering Sea, Amy E. Wirts, Gregory C. Johnson
Journal of Marine Research
Recent seasonal and interannual variability of the upper ocean in the southeast Aleutian Basin of the Bering Sea is related to air sea fluxes, ocean advection, and mixing. Between the winter of 2001/2002 and that of 2002/2003 a warming and freshening of the upper ocean was observed in data from a regional array of profiling Conductivity-Temperature-Depth (CTD) floats. The mild winter of 2002/2003 resulted in an unusually warm, fresh, light, and shallow winter mixed layer and a weakly ventilated temperature minimum layer. These unusual winter conditions contributed to a substantial reduction in the subsurface temperature inversion characteristic of the southeast …
Determination Of Dynamic Heights In The Bay Of Bengal From Xbt Profiles And Climatological Salinities, M. M. Ali, V. V. Gopalakrishna, Nilesh Araligidad, G. Venkata Reddy, G. Salgoanker
Determination Of Dynamic Heights In The Bay Of Bengal From Xbt Profiles And Climatological Salinities, M. M. Ali, V. V. Gopalakrishna, Nilesh Araligidad, G. Venkata Reddy, G. Salgoanker
Journal of Marine Research
Dynamic height (DH) computations are necessary for the estimation of geostrophic currents, heat transport studies, identification of eddies and to validate the altimeter sea surface height (SSH) observations. To compute DHs we need the temperature and salinity profiles to a reasonable deeper level. But, temperature profiles alone, such as from XBT (expendable bathy thermograph), are more numerous than combined temperature and salinity measurements from CTD (conductivity, temperature and depth). To use these voluminous temperature measurements from XBT observations in the computation of DHs, temperature/salinity relations were developed in many oceanic regions. Since such an exercise cannot be carried out in …
Life In The Lee: Local Distributions And Orientations Of Honeycomb Worms Along The California Coast, Stacey A. Simmons, Richard K. Zimmer, Cheryl Ann Zimmer
Life In The Lee: Local Distributions And Orientations Of Honeycomb Worms Along The California Coast, Stacey A. Simmons, Richard K. Zimmer, Cheryl Ann Zimmer
Journal of Marine Research
In the rocky intertidal, invertebrates living in dense, intraspecific groups may be particularly important community members because they provide structural habitat for other species. Despite the prevalence of conspecific aggregates, there is scant knowledge of the proximate and ultimate causes of their distributions. Phragmatopoma californica is a gregarious, suspension-feeding tubeworm that forms extensive reefs ("honeycombs") along the California coast. Local distributions and sizes of worm aggregations, tube orientations and worm mass were quantified to identify patterns and generate hypotheses regarding potential structuring processes. Field surveys were conducted at five intertidal boulder fields in northern and southern California, spanning much of …
Thermohaline Circulation Induced By Bottom Friction In Sloping-Boundary Basins, Johan Nilsson, Gösta Walin, Göran Broström
Thermohaline Circulation Induced By Bottom Friction In Sloping-Boundary Basins, Johan Nilsson, Gösta Walin, Göran Broström
Journal of Marine Research
We show that a velocity field in geostrophic and hydrostatic balance on the f-plane can be diagnosed from an arbitrarily prescribed distribution of buoyancy in a basin with closed depth contours. We emphasize the steady-state circulation associated with a large-scale horizontal buoyancy gradient, attained in the absence of wind forcing. For inviscid motion, the diagnosed field contains a free barotropic along-isobath flow which can be chosen arbitrarily, e.g. in such a way that the buoyant "southern" pool of surface water essentially recirculates. Including bottom friction, we show that steady motion requires that the net Ekman transport across closed depth …
Spatial Linkages Between Decapod Planktonic And Benthic Adult Stages In A Newfoundland Fjordic System, Pedro A. Quijón, Paul V. R. Snelgrove
Spatial Linkages Between Decapod Planktonic And Benthic Adult Stages In A Newfoundland Fjordic System, Pedro A. Quijón, Paul V. R. Snelgrove
Journal of Marine Research
The relative importance of predatory decapod crustaceans in sedimentary communities depends on the spatial variability in their abundance and composition. At the scale of a fjord, such spatial patterns could be related to sill-mediated larval supply. This study examines larval and adult distributions of abundant predatory decapods at six representative sites in a sub-arctic Newfoundland fjord during three consecutive summers. Adult snow crab (Chionoecetes opilio) and toad crab (Hyas coarctatus, H. araneus) characterized outer areas of the fjord, whereas pandalid shrimp (Pandalus montagui) dominated inner areas, and rock crab (Cancer irroratus) showed …
On The Subduction Of Upwelled Waters In The California Current, Steven J. Bograd, Arnold W. Mantyla
On The Subduction Of Upwelled Waters In The California Current, Steven J. Bograd, Arnold W. Mantyla
Journal of Marine Research
We use 20 years of hydrographic data from the California Cooperative Oceanic Fisheries Investigations (CalCOFI) program off southern California to search for water mass signatures of subducted upwelled waters. A search for secondary oxygen maxima in more than 6000 water column profiles identified 629 cases of deep oxygen inversions. The additional criteria of a minimum magnitude of the deep oxygen inversion and an accompanying reduction in dissolved nutrients identified 106 (∼17%) of these as subduction signatures. The physical and chemical characteristics of these water masses suggest that they had been photosynthetically modified in the euphotic zone, and perhaps ventilated at …