The processes determining the concentration of oxygen, phosphate and other organic derivatives within the depths of the Atlantic Ocean

Redfield, Alfred C.

doi:10.1575/1912/1053

Cited by 57 publications

(44 citation statements)

References 5 publications

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“…The initial phosphate can be regarded as conservative property such as potential temperature and salinity as long as the relationship between phosphate regeneration and dissolved oxygen consumption is held (Broecker et al, 1985). Redfield (1942) applied this concept to an isopycnal analysis for the North and South Atlantic, and showed that the phosphate maximum lying 400-1000 m depth on mid-latitude originates at the Antarctic convergence. Broecker et al (1985) showed that initial phosphate contents calculated from the regeneration ratio 350, based on the oxygen-phosphate relationships on selected isopycnal surfaces in various oceanic regions, are almost conservative and elucidated the origin of the salinity maximum water in the Antarctic.…”

Section: Discussionmentioning

confidence: 99%

The upper portion of the Japan Sea Proper Water; Its source and circulation as deduced from isopycnal analysis

Senjyu

Sudo

1994

J Oceanogr

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All of the available hydrographic station data (temperature, salinity, dissolved oxygen, phosphate and nitrate) taken in various seasons from 1964 to 1985 are analyzed to show where the upper portion of the Japan Sea Proper Water (UJSPW) is formed and how it circulates. From vertical distributions of water properties, the Japan Sea Proper Water can be divided into an upper portion and a deep water at the σ 1 (potential density referred to 1000 db) depth of 32.05 kg m -3 surface. The UJSPW in the north of 40°N increases in dissolved oxygen contents and decreases in phosphate contents in winter, while no significant seasonal variation is seen in the south of 40°N. Initial nutrient contents calculated from relationships between AOU and nutrients on isopycnal surfaces show no significant regional difference in the Japan Sea; this suggests that the UJSPW has originated from a single water mass. From depth, dissolved oxygen and phosphate distributions on σ 1 32.03 kg m -3 surface, core thickness distribution and subsurface phosphate distribution, it is inferred that the UJSPW is formed by the wintertime convection in the region west of 136°E between 40° and 43°N, and advected into the region west of the Yamato Rise along the Continent; finally, it must enter into the Yamato Basin.

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Section: Discussionmentioning

confidence: 99%

The upper portion of the Japan Sea Proper Water; Its source and circulation as deduced from isopycnal analysis

Senjyu

Sudo

1994

J Oceanogr

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“…This may be partially overcome by exploiting the nitrate-density relationship that has long been known to be more robust than the relationship between nitrate and depth across the main pycnocline (Redfield, 1944;Pytkowicz and Kester, 1966). In some areas, the nutrient-depleted near-surface layer transitions abruptly to a uniform gradient of nitrate with respect to density (termed the nitracline slope), whereas in others, the transition is more gradual, leading to curvature in the nitratedensity relationship.…”

Section: Introductionmentioning

confidence: 99%

The shape of the oceanic nitracline

Omand

Mahadevan

2015

Biogeosciences

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Abstract. In most regions of the ocean, nitrate is depleted near the surface by phytoplankton consumption and increases with depth, exhibiting a strong vertical gradient in the pycnocline (here referred to as the nitracline). The vertical supply of nutrients to the surface euphotic zone is influenced by the vertical gradient (slope) of the nitracline and by the vertical separation (depth) of the nitracline from the sunlit surface layer. Hence it is important to understand the shape (slope and curvature) and depth of the oceanic nitracline.By using density coordinates to analyze nitrate profiles from autonomous Autonomous Profiling EXplorer floats with InSitu Ultraviolet Spectrophotometers (APEX-ISUS) and shipbased platforms (World Ocean Atlas -WOA09; Hawaii Ocean Time-series -HOT; Bermuda Atlantic Time-series Study -BATS; and California Cooperative Oceanic Fisheries Investigations -CalCOFI), we are able to eliminate much of the spatial and temporal variability in the profiles and derive robust relationships between nitrate and density. This allows us to characterize the depth, slope and curvature of the nitracline in different regions of the world's oceans. The analysis reveals distinguishing patterns in the nitracline between subtropical gyres, upwelling regions and subpolar gyres. We propose a one-dimensional, mechanistic model that relates the shape of the nitracline to the relative depths of the surface mixed layer and euphotic layer. Though heuristic, the model accounts for some of the seasonal patterns and regional differences in the nitrate-density relationships seen in the data.

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“…5), ifwe assume that oxygen consumption in the deep lake is driven by the oxidation of organic matter, then -400 mmol m-2 of carbon are required to account for the observed oxygen deficit accrued between 26 June and 19 January. This calculation assumes a ratio of -1 3802 : 106C for oxygen consumed via the oxidation of organic matter (Redfield 1942;Redfield et al 1963).…”

Section: Discussionmentioning

confidence: 99%

Spatial and temporal distribution of dissolved oxygen in Crater Lake,Oregon

McManus

Collier

Dymond

et al. 1996

Limnology & Oceanography

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Small temporal and spatial variations in the distribution of dissolved oxygen in Crater Lake, Oregon, are used to estimate the mean age of the lake's deep water, the flux of labile organic carbon to the deep lake, and the influence of hydrothermal activity on the concentration of dissolved oxygen within the lake. An increase in the concentration of dissolved oxygen in the deep water during winter [1988][1989] indicates that 30-45% of deep water was replaced with well-oxygenated surface water. This deep-water renewal corresponds to a mean deep water residence time of 2-4 yr. The deep-water oxygen consumption rate is 2 l-26 pmol m-3 d-l, which occurs primarily through the oxidation of organic matter and, to a lesser extent, the oxidation of reduced inorganic species that are introduced to the lake via subsurface hydrothermal springs.Dissolved oxygen is a sensitive tracer of the physical and chemical processes occurring in an aquatic system. Oxygen in excess of atmospheric saturation in the upper water column is caused by photosynthesis, in situ warming of the water column by penetration of solar radiation, and air bubble injection (Jenkins and Goldman 1985;Emerson et al. 199 1). The decrease (consumption) in dissolved oxygen at depth typically results from oxidation of particulate organic material raining out of the euphotic zone. If the photosynthetic component of the oxygen excess in the upper water column is properly constrained, then this component should have nearly the same value, but opposite in sign, as the amount of oxygen consumed in deep water. This balance between surface excess photosynthesis and deep-water respiration assumes that only a small portion of the photosynthetically derived carbon is buried in sediments.Because of the consumption of oxygen at depth in an aquatic system, deep water is generally undersaturated with respect to atmospheric saturation. In temperate lakes, oxygen-rich wintertime surface water mixes with deep water, resulting in a net increase in dissolved oxygen at depth at the time of mixing. This change in oxygen pro- AcknowledgmentsMark Buktcnica, James Milestone, John Salinas, and Scott Stonum provided day and night field support for this research; their efforts arc greatly appreciated. The field and analytical efforts of the OSU research team were invaluable. Eric Olsen and Marv Lilley provided the unpublished methane data. Special thanks are extended to Roberta Conard and Chris Moser.

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The processes determining the concentration of oxygen, phosphate and other organic derivatives within the depths of the Atlantic Ocean

Cited by 57 publications

References 5 publications

The upper portion of the Japan Sea Proper Water; Its source and circulation as deduced from isopycnal analysis

The upper portion of the Japan Sea Proper Water; Its source and circulation as deduced from isopycnal analysis

The shape of the oceanic nitracline

Spatial and temporal distribution of dissolved oxygen in Crater Lake,Oregon

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