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Showing papers by "Woods Hole Oceanographic Institution published in 1981"


Journal ArticleDOI
TL;DR: In this article, the authors studied the upper ocean response to a moving hurricane using historical air-sea data and a three-dimensional numerical ocean model, and found that entrainment caused 85% of the irreversible heat flux into the ML.
Abstract: The upper ocean response to a moving hurricane is studied using historical air-sea data and a three-dimensional numerical ocean model. Sea surface temperature (SST) response is emphasized. The model has a surface mixed-layer (ML) that entrains according to a velocity dependent parameterization, and two lower layers that simulate the response in the thermocline. The passage of Hurricane Eloise (1975) over buoy EB-10 is simulated in detail. SST decreased 2°C as Eloise passed directly over EB-10 at 8.5 m s−1. Model results indicate that entrainment caused 85% of the irreversible heat flux into the ML; air-sea heat exchange accounted for the remainder. The maximum SST response was predicted to be −3°C and to occur 60 km to the right of the hurricane track. This is consistent with the well-documented rightward bias in the SST response to rapidly moving hurricanes. The rightward bias occurs in the model solution because the hurricane wind-stress vector turns clockwise with time on the right side of the...

1,157 citations


Journal ArticleDOI
17 Jul 1981-Science
TL;DR: The existence of a symbiotic association between vestimentiferan tube worms from deep-sea hydrothermal vents and chemoautotrophic sulfur-oxidizing prokaryotes, based on histological and enzymatic evidence, is suggested.
Abstract: The existence of a symbiotic association between vestimentiferan tube worms from deep-sea hydrothermal vents and chemoautotrophic sulfur-oxidizing prokaryotes, based on histological and enzymatic evidence, is suggested.

631 citations


Journal ArticleDOI
01 Feb 1981
TL;DR: In this article, the adsorption properties of sinking particulate matter in the deep subtropical Atlantic Ocean are modeled by combining the field observations of trace metal scavenging with theoretical surface chemistry.
Abstract: The adsorption properties of sinking particulate matter in the deep subtropical Atlantic Ocean are modeled by combining the field observations of trace metal scavenging with theoretical surface chemistry The treatment yields equilibrium constants that define metal interactions with deep-ocean particles These equilibrium constants can be compared with those that define metal interactions with typical metal oxides and organic compounds The comparison indicates that metal-particulate matter interactions closely resemble the interactions between organic compounds and metals Therefore, it is suggested that the adsorption properties of marine particulate matter are controlled by organic coatings In addition, quantifying the surface properties of deep-ocean particles provides a means for estimating the scavenging residence times for metals for which the determination has not yet been made

367 citations


Journal ArticleDOI
TL;DR: In this article, a positive feedback loop was proposed to explain the sediment redox condition and S. aZterni$oru production in the tall form of Spurtina alterniflora.
Abstract: Spurtina alterniflora oxidizes the sediments in which it grows through both passive oxygen release and active metabolic processes. Eh is higher in the root zone of this grass than in the sediment below the root zone or in unvegetated sediments. Sediments underlying the tall form of S. aZterniJorcl are more oxidized than those under the short form, and sediment redox condition and S. aZterni$oru production are related through a positive feedback loop. Reducing conditions inhibit aboveground grass production. But also, more productive plants have a greater capacity for sediment oxidation, as shown by the increased Eh in fertilized plots. Waterlogged sediments inhibit plan growth by decreasing passive oxygen release and thereby lowering Eh.

358 citations


Journal ArticleDOI
01 May 1981
TL;DR: For example, the Sargasso Sea has been sampled by sediment trap nearly continuously for more than two years as discussed by the authors and the flux variations appear closely tied to the annual cycle of primary production in the surface water, which peaks in early spring and reaches a low in late fall.
Abstract: The flux of particles approaching the sea floor near Bermuda has been sampled by sediment trap nearly continuously for more than two years. The trap was placed at a depth of 3200 m, 1000 m above the bottom, and samples were recovered at two-month intervals. All major components of the sediment (biogenic carbonate and silicate, and organic matter) and a minor, presumably aeolian, clay component, as well as all size fractions (after sieving) were delivered in seasonally fluctuating amounts. The flux variations appear closely tied to the annual cycle of primary production in the surface water, which in the Sargasso Sea peaks in early spring and reaches a low in late fall. The total particulate flux varied by a factor of three (20 to 60 mg m−2 d−1), but some components varied by more than an order of magnitude. The close synchroneity between surface production and deep-water arrival of even fine particles, which presumably sink as components of larger aggregates, indicates extremely rapid settling of the bulk of the sediment. The evidence that even the flux of inorganic particles varies in phase with the primary production cycle suggests that an efficient mechanism exists for rapid removal from the mixed layer and transfer to deep water of many chemicals, including pollutants, which are associated with, or scavenged by, biogenic and aeolian particles.

338 citations


Journal ArticleDOI
17 Dec 1981-Nature
Abstract: The composition of the atmosphere is influenced both directly and indirectly by biological activity. Evidence is presented here to suggest that nitrification in soil is a potentially significant source of both NO and N2O. Between 0.3 and 10% of the ammonium oxidized by cultures of the soil bacterium Nitrosomonas europaea is converted to these gases. The global source for NO associated with nitrification could be as large as 15,000,000 tonnes N/yr, with a source for N2O of 5,000,000-10,000,000 tonnes N/yr. Nitric oxide has a key role in tropospheric chemistry, participating in a complex set of reactions regulating OH and O3. Nitrous oxide is a dominant source of stratospheric NO and has a significant influence on climate.

312 citations



Journal ArticleDOI
TL;DR: In this article, the carbon and oxygen isotopic compositions of 149 samples of benthic foraminifera from deep-sea core tops indicate that none of the nine species studied secrete calcium carbonate in isotopic equilibrium with ambient bottom water.

291 citations


Journal ArticleDOI
01 Oct 1981-Ecology
TL;DR: In this paper, the authors introduced a new model of gases gas transport wherein the gases move through waterlilies in a mass flow, and the internal gas spaces in Nuphar constitute a pressurized flow-through system, with ambient air entering the youngest emergent leaves against a small gradient in total gas pressure.
Abstract: Current models of gas transport in aquatic plants hold that gases diffuse in an essentially static gas phase within the lacunae according to gradients in their individual partial pressures. This study introduces a new model of gases gas transport wherein the gases move through waterlilies in a mass flow. The internal gas spaces in Nuphar constitute a pressurized flow—through system, with ambient air entering the youngest emergent leaves against a small gradient in total gas pressure. This pressurization phenomenon is the result of purely physical processes driven by the gradients in temperature (thermal transpiration) and water vapor (hygrometric pressure) between the atmosphere and the lacunae of the youngest emergent leaves. The lacunae are continuous throughout the entire plant, and the older leaves vent the elevated pressure generated by the younger leaves. This arrangement gives rise to a flow—through pattern, accelerating both the rate of O2 supply from the atmosphere to the roots, and the rate of CO2 and CH4 transport from the roots towards the atmosphere. This ventilation system represents an important adaptation by the waterlily to life in anaerobic sediments.

259 citations


Journal ArticleDOI
TL;DR: In this paper, a double diffusive mechanism was proposed to explain the observed constancy of Rρ in the main thermocline, based on the evidence from theory, experiment and observation that the intensity of salt-finger convection is a strong function of the Rρ.
Abstract: Ingham (1966) reported that the temperature-salinity relationships in the Central Waters were much better described by a curve of constant density ratio (Rρ = αΔT/βΔS) than by a straight line. His result is quantitatively verified and a simple, but powerful, double-diffusive mechanism is proposed to explain the observed constancy of Rρ in the main thermocline. The mechanism is based on the evidence from theory, experiment and observation that the intensity of salt-finger convection is a strong function of Rρ. This dependence, plus the fact that more salt than heat is transferred by the fingers, causes any deviation from a constant Rρ to be the site of convergence or divergence of the vertical salt flux that acts to remove the perturbation in Rρ. A linear treatment of the mechanism shows that Rρ can be “diffused” with an effective diffusivity that is much greater than the diffusivities of heat or mass. A few numerical examples illustrate the predicted effects of salt fingering on the T-S relation,...

245 citations


Journal ArticleDOI
TL;DR: Foraminifera recovered from six successive sediment-trap samples collected over fourteen months at a depth of 3200 m near Bermuda show varied responses to seasonal changes in the near-surface hydrography as discussed by the authors.

Journal ArticleDOI
28 May 1981-Nature
TL;DR: In this paper, the authors report the temporal variation of the transport of continentally-derived lipids (hydrocarbons, fatty alcohols and fatty acids) to the central tropical North Pacific.
Abstract: Lipid class compounds have been used as source markers to ascertain the terrestrial, marine, or anthropogenic origin of atmospheric aerosols from rural continental and coastal oceanic environments1–11 However, there are only limited data on the composition and source of lipids in remote marine aerosols Studies off the West African coast suggest that surface waxes of terrestrial vascular plants are a major source of lipid class compounds in dust samples6,11 Uniform concentrations of lipids found7,10 in aerosols from urban, rural and oceanic regions imply either a long residence time for continental material or a uniform production rate of the compounds over the oceans It has also been concluded1–3,8 that oceanic aerosols have significant marine sources However, previous organic chemical studies have not been conducted in conjunction with other chemical analyses of the aerosols or with climatological and meteorological studies We report here, as part of the Sea/Air Exchange Program (SEAREX), the temporal variation of the transport of continentally-derived lipids (hydrocarbons, fatty alcohols and fatty acids) to the central tropical North Pacific

Journal ArticleDOI
TL;DR: In this paper, the concentrations and isotopic composition of helium in oceanic basaltic glass both by melting and by crushing in vacuo were determined and a significant fraction of the helium was released by crushing, confirming that it resides within the vesicles.

Journal ArticleDOI
TL;DR: In general, species from coastal regions can reproduce as rapidly or more rapidly in continuous light than in a 14: 10 LD cycle, while most species from oceanic regions are harmed by continuous light.

Journal ArticleDOI
TL;DR: In this article, a model for internal-wave energy dissipation predicts dissipation as weak ever the some scales, for reasonable values of the total dissipation, assuming dissipation at small scales, such as in the proposed model, and generation at large scales, a consistent dynamic balance with a constant downscale energy flux under nonlocal nonlinear interactions reproduces the observed spectral dependencies.
Abstract: For oceanic internal waves with vertical scales larger than 1 m the evolution of the spectrum is adequately described by weak-interaction theory. Based on simple physical arguments, a model for internal-wave energy dissipation predicts dissipation as weak ever the some scales, for reasonable values of the total dissipation. Assuming dissipation at small scales, such as in our proposed model, and generation at large scales, a consistent dynamic balance with a constant downscale energy flux under nonlocal nonlinear interactions reproduces the observed spectral dependencies. A small-scale break point at which the total shear reaches a given value, and beyond which dissipation is important, is determined by the level and bandwidth of the energy-containing waves.

Journal ArticleDOI
TL;DR: In this article, the equivalence points of the carbonic acid system on this titration curve were developed in 1971 but have not previously been published, and applied to the GEOSECS program by computer-controlled potentiometric titration technique.

Journal ArticleDOI
TL;DR: In this article, the role of internal friction in the evolution of a two-dimensional front in a rotating stratified fluid is examined, with results being presented for a semi-analytic diagnostic model, which is fitted to two particular continental shelf fronts.
Abstract: We examine the role of internal friction in the evolution of a two-dimensional front in a rotating stratified fluid. For a two-layer fluid with interfacial friction the depth of the frontal interface satisfies a diffusion equation with respect to time and the cross-frontal coordinate. Similarity solutions are used to compare the behaviour of the front for linear and quadratic interfacial friction laws. For a continuously stratified front a simple formula is derived for the cross-frontal flow induced by friction, parametrized in terms of an eddy viscosity coefficient Av, provided that the Rossby and Ekman numbers are small. Outside surface and bottom Ekman layers the deptht) of an isopycnal with density p satisfies the diffusion equation z t — [(A 1 2/ / 2) where are the Vaisala and Coriolis frequencies, x is the cross-frontal coordinate and t is time. The consequences of this for the evolution and maintenance of a front are discussed. The circulation in tidal mixing fronts is examined, with results being presented for a semi-analytic diagnostic model, which is fitted to two particular continental shelf fronts. A prominent feature is a two-cell circulation pattern in the plane normal to the front. A variety of cross-frontal transfer mechanisms are discussed, with order-of-magnitude comparisons of their importance being made. Transfer by the mean flow appears to be more important than either shear flow dispersion or the flux associated with baroclinic eddies, but the results are sensitive to the parametrization of vertical mixing of momentum.


Journal ArticleDOI
TL;DR: Basalts collected by dredging between 23°N and 25°N include samples from the active spreading ridges, median valley walls, and older walls of the Kane Fracture Zone transform fault at about 24°N as discussed by the authors.
Abstract: Basalts collected by dredging between 23°N and 25°N include samples from the active spreading ridges, median valley walls, and older walls of the Kane Fracture Zone transform fault at about 24°N. Chemical analyses of over 100 basalts and basalt glasses show the depletion in large ion lithophile elements characteristic of ‘normal’ ocean ridge basalts. Basalt suites recovered from the median valley north and south of the fracture zone are almost identical geochemically. There is no evidence of present or past volcanic activity within the transform zone. Petrogenesis of the basalts, as deduced from both petrographic and geochemical evidence, indicates that simple low-pressure equilibrium crystallization during ascent in shallow vents or flow in seafloor lava tubes can account for a large part of the major element and trace element variation within discrete data subsets. However, more complex models are required to explain relations between samples showing large differences in large ion lithophile element enrichments. A subset of samples of intermediate composition can be explained by simple mixing of highly fractionated basalt with mafic parental basalt. A number of basalts enriched in Al2O3 may reflect accumulation and partial resorption of plagioclase. By comparison to existing phase equilibria experiments, it is shown that a basalt-type common to the area is a logical choice as a mantle-derived primary magma; it is close to the composition of average normal MORB with wt % TiO2 ≅ 1.50, Mg# ≅ 66, and normative olivine 10–15 wt %. This composition is inferred to have separated from the mantle at a pressure of about 8–9 kbar. Rare examples of more mafic ‘primary’ basalt are present and are inferred to represent melts which escaped from the mantle at higher pressures. We outline a comprehensive hypothesis for melting, fractionation, and mixing which we believe may be adequate to explain compositional variation in these and other suites of ‘normal MORB.’ An important consequence of this model is that MORB presently at a given position on a low-pressure, multiply saturated cotectic may have reached that point by a variety of paths; some may be nearly direct mantle derivatives, while others may have experienced a complex history of polybaric and low-pressure fractionation and/or mixing.

Journal ArticleDOI
TL;DR: This article corrects the article on p. 531 in vol.
Abstract: A microscopic survey is presented of the most commonly observed and morphologically conspicuous microorganisms found attached to natural surfaces or to artificial materials deposited in the immediate vicinity of thermal submarine vents at the Galapagos Rift ocean spreading zone at a depth of 2,550 meters. Of special interest were the following findings: (i) all surfaces intermittently exposed to H 2 S-containing hydrothermal fluid were covered by layers, ca. 5 to 10 μm thick, of procaryotic, gram-negative cells interspaced with amorphous metal (Mn-Fe) deposits; (ii) although some of the cells were encased by dense metal deposits, there was little apparent correlation between metal deposition and the occurrence of microbial mats, (iii) highly differentiated forms appeared to be analogues of certain cyanobacteria, (iv) isolates from massive mats of a prosthecate bacterium could be identified as Hyphomicrobium spp., (v) intracellular membrane systems similar to those found in methylotrophic and nitrifying bacteria were observed in approximately 20% of the cells composing the mats, (vi) thiosulfate enrichments made from mat material resulted in isolations of different types of sulfur-oxidizing bacteria including the obligately chemolithotrophic genus Thiomicrospira. Images

Journal ArticleDOI
TL;DR: It is concluded that polyphenols in F. vesiculosus and A. nodosum are functionally similar to terrestrial plant polyphenol (tannins) in providing chemical defenses against herbivores.
Abstract: Polyphenols from two brown algae,Fucus vesiculosus (L.) andAscophyllum nodosum (L.) Le Jolis, inhibited feeding by the herbivorous snail,Littorina littorea. The active compounds were characterized as phloroglucinol polymers with a wide molecular weight range (mol wt 300,000) by spectroscopic, Ultrafiltration, thin-layer chromatographic, and chemical degradation data. As little as 1% (dry wt) polyphenol in food reduced feeding by more than 50%, and polyphenolic extracts inhibited feeding entirely when present in concentrations of 2–5% (dry wt). Commercially available phloroglucinol dihydrate and gallotannin, which are known herbivore feeding deterrents in terrestrial plants, inhibitedL. littorea feeding when added to food media in concentrations similar to those above. We conclude that polyphenols inF. vesiculosus andA. nodosum are functionally similar to terrestrial plant polyphenols (tannins) in providing chemical defenses against herbivores. This research is the first demonstration that chemical compounds defend these two dominant, perennial marine algae from the major herbivore found in their community.

Journal ArticleDOI
TL;DR: Foraminifera from plankton tows, sediment traps and sediments in the central North Atlantic were studied in order to understand what determines their oxygen and carbon isotope composition as discussed by the authors.

Journal ArticleDOI
TL;DR: The presence of chemolithotrophic sulfur-oxidizing bacteria in the sulfide-containing hydrothermal water supports the hypothesis that chemosynthesis provides a substantial primary food source for the rich populations of invertebrates found in the immediate vicinity of the vents.
Abstract: Three distinct physiological types of sulfur-oxidizing bacteria were enriched and isolated from samples collected at several deep-sea hydrothermal vents (2,550 m) of the Galapagos Rift ocean floor spreading center. Twelve strains of the obligately chemolithotrophic genus Thiomicrospira were obtained from venting water and from microbial mats covering surfaces in the immediate vicinity of the vents. From these and other sources two types of obligately heterotrophic sulfur oxidizers were repeatedly isolated that presumably oxidized thiosulfate either to sulfate (acid producing; 9 strains) or to polythionates (base producing; 74 strains). The former were thiobacilli-like, exhibiting a thiosulfate-stimulated increase in growth and CO(2) incorporation, whereas the latter were similar to previously encountered pseudomonad-like heterotrophs. The presence of chemolithotrophic sulfur-oxidizing bacteria in the sulfide-containing hydrothermal water supports the hypothesis that chemosynthesis provides a substantial primary food source for the rich populations of invertebrates found in the immediate vicinity of the vents.

Journal ArticleDOI
TL;DR: Nitrogen-starved plants of the red alga Gracilaria tikvahiae assimilate ammonium-nitrogen very rapidly, doubling their total tissue nitrogen content in 8 h or less, and their growth rate declines.


Journal ArticleDOI
TL;DR: In this article, an extension of Stern's 1967 study of the stability of a thermohaline front to intrusive finestructure driven by salt fingers is presented to investigate this hypothesis, and the model requires initial perturbations in the front which can support salt fingers.

Journal ArticleDOI
TL;DR: In the Galapagos Rift at 21°N, a linear fissure 8 km long running parallel to the valley axis has been identified as mentioned in this paper, which is part of a larger en echelon pattern of eruptive fissures.

Journal ArticleDOI
TL;DR: The results of an in situ experiment in the Panama Basin allow us to determine the way in which planktonic foraminiferal assemblages are modified by calcite dissolution as mentioned in this paper.

Journal ArticleDOI
TL;DR: In this article, the major element composition of in situ sampled pore waters are reported for the North Atlantic and Southern Ocean between Africa and Antarctica, and the changes observed and calculated fluxes across the seawater-sediment interface are much the same as those reported previously for other areas of the Atlantic and Caribbean.

Journal ArticleDOI
TL;DR: In biology, the study of geomagnetic orientation has gained new momentum since the discovery of magnetic field detectors in aquatic organisms and the ability of sharks and rays to orient to the earth's magnetic field has been demonstrated in behavioral experiments as discussed by the authors.
Abstract: In biology, the study of geomagnetic orientation has gained new momentum since the discovery of magnetic field detectors in aquatic organisms. Sharks and rays respond to dc and low frequency voltage gradients of 0.005 μV/cm. By moving through the earth's magnetic field, they induce electric fields well within the sensitivity range of their keen electric sense. As these fields depend on the direction in which the animal is heading, the induced voltage gradients may serve as the biophysical basis of an electromagnetic compass sense. The ability of sharks and rays to orient to the earth's magnetic field has been demonstrated in behavioral experiments. Also, various marine and freshwater mud bacteria are endowed with permanent magnetic dipole moments, directed parallel to the axis of motility. When separated from the sediments, these bacteria return to the mud by migrating downward along the earth's inclined magnetic field lines. Their orientation is largely determined by the principles of statistical mechanics and may be expressed in terms of the directive magnetic force, the randomizing effect of thermal agitation, and the cells' flagellar thrust. Observations on live bacteria yield individual dipole moments circa 15 × kT/G.