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Institution

Woods Hole Oceanographic Institution

NonprofitFalmouth, Massachusetts, United States
About: Woods Hole Oceanographic Institution is a nonprofit organization based out in Falmouth, Massachusetts, United States. It is known for research contribution in the topics: Population & Mantle (geology). The organization has 5685 authors who have published 18396 publications receiving 1202050 citations. The organization is also known as: WHOI.


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Journal ArticleDOI
TL;DR: In this paper, a relation for the diffusivity of vertical mixing is formulated for regions where internal tides dissipate their energy as turbulence, consistent with an estimate based on microstructure observations from a mid-ocean ridge site.
Abstract: [1] Using a parameterization for internal wave energy flux in a hydrodynamic model for the tides, we estimate the global distribution of tidal energy available for enhanced turbulent mixing. A relation for the diffusivity of vertical mixing is formulated for regions where internal tides dissipate their energy as turbulence. We assume that 30 ± 10% of the internal tide energy flux dissipates as turbulence near the site of generation, consistent with an estimate based on microstructure observations from a mid-ocean ridge site. Enhanced levels of mixing are modeled to decay away from topography, in a manner consistent with these observations. Parameterized diffusivities are shown to resemble observed abyssal mixing rates, with estimated uncertainties comparable to standard errors associated with budget and microstructure methods.

304 citations

Journal ArticleDOI
07 Sep 2000-Nature
TL;DR: Detailed observations of the velocity structure with a high data coverage suggest that the picture of the formation and spreading of Labrador Sea water may have to be revised, and future studies with similar instrumentation will allow new insights on the intermediate depth ocean circulation.
Abstract: The Labrador Sea is one of the sites where convection exports surface water to the deep ocean in winter as part of the thermohaline circulation. Labrador Sea water is characteristically cold and fresh, and it can be traced at intermediate depths (500–2,000 m) across the North Atlantic Ocean, to the south and to the east of the Labrador Sea1,2,3. Widespread observations of the ocean currents that lead to this distribution of Labrador Sea water have, however, been difficult and therefore scarce. We have used more than 200 subsurface floats to measure directly basin-wide horizontal velocities at various depths in the Labrador and Irminger seas. We observe unanticipated recirculations of the mid-depth (∼700 m) cyclonic boundary currents in both basins, leading to an anticyclonic flow in the interior of the Labrador basin. About 40% of the floats from the region of deep convection left the basin within one year and were rapidly transported in the anticyclonic flow to the Irminger basin, and also eastwards into the subpolar gyre. Surprisingly, the float tracks did not clearly depict the deep western boundary current, which is the expected main pathway of Labrador Sea water in the thermohaline circulation. Rather, the flow along the boundary near Flemish Cap is dominated by eddies that transport water offshore. Our detailed observations of the velocity structure with a high data coverage suggest that we may have to revise our picture of the formation and spreading of Labrador Sea water, and future studies with similar instrumentation will allow new insights on the intermediate depth ocean circulation.

304 citations

Journal ArticleDOI
10 May 2001-Nature
TL;DR: A three-dimensional viscoelastic model that simulates stress transfer from the ductile lower crust and upper mantle to the brittle upper crust in the 7 years following the Landers earthquake suggests that lower-crustal or upper-mantle flow can lead to postseismic stress increases of up to 1–2 bar at the location of the Hector Mine hypocentre during this time period.
Abstract: Stress changes in the crust due to an earthquake can hasten the failure of neighbouring faults and induce earthquake sequences in some cases1,2,3,4,5. The 1999 Hector Mine earthquake in southern California (magnitude 7.1) occurred only 20 km from, and 7 years after, the 1992 Landers earthquake (magnitude 7.3). This suggests that the Hector Mine earthquake was triggered in some fashion by the earlier event. But uncertainties in the slip distribution and rock friction properties associated with the Landers earthquake have led to widely varying estimates of both the magnitude and sign of the resulting stress change that would be induced at the location of the Hector Mine hypocentre—with estimates varying from -1.4 bar (ref. 6) to +0.5 bar (ref. 7). More importantly, coseismic stress changes alone cannot satisfactorily explain the delay of 7 years between the two events. Here we present the results of a three-dimensional viscoelastic model that simulates stress transfer from the ductile lower crust and upper mantle to the brittle upper crust in the 7 years following the Landers earthquake. Using viscoelastic parameters that can reproduce the observed horizontal surface deformation following the Landers earthquake, our calculations suggest that lower-crustal or upper-mantle flow can lead to postseismic stress increases of up to 1–2 bar at the location of the Hector Mine hypocentre during this time period, contributing to the eventual occurrence of the 1999 Hector Mine earthquake. These results attest to the importance of considering viscoelastic processes in the assessment of seismic hazard8,9,10,11.

303 citations

Journal ArticleDOI
01 Oct 1991-Nature
TL;DR: In this article, a re-evaluation of existing 234Th data is presented, which indicates that trap-derived and model-derived 234Th particle fluxes can differ by a factor of ±3-10, suggesting that shallow traps may not provide an accurate measure of particle flux.
Abstract: SEDIMENT traps are widely used to measure the vertical flux of particulate matter in the oceans. In the upper ocean, sediment traps have been used to determine the extent to which CO2 Axed by primary producers is exported as particulate organic carbon1–3. In addition, the observed decrease of particle flux with depth has been used to predict regeneration rates of organic matter and associated elements3. Over seasonal or annual timescales, the import of limiting nutrients into the upper ocean (new production) should be balanced by particle export4,5. Given the importance of accurately determining the sinking particle flux, it has been suggested that 234Th might be used to 'calibrate' shallow-trap fluxes6. Here I present a re-evaluation of existing 234Th data which indicates that trap-derived and model-derived 234Th particle fluxes can differ by a factor of ±3–10, suggesting that shallow traps may not provide an accurate measure of particle fluxes.

303 citations

Journal ArticleDOI
TL;DR: In this paper, the authors evaluate the physiological underpinnings of global variations in satellite-based phytoplankton chlorophyll fluorescence and find that the three dominant factors influencing fluorescence distributions are chilophyll concentration, pigment packaging effects on light absorption, and light-dependent energy-quenching processes.
Abstract: . Phytoplankton photosynthesis links global ocean biology and climate-driven fluctuations in the physical environment. These interactions are largely expressed through changes in phytoplankton physiology, but physiological status has proven extremely challenging to characterize globally. Phytoplankton fluorescence does provide a rich source of physiological information long exploited in laboratory and field studies, and is now observed from space. Here we evaluate the physiological underpinnings of global variations in satellite-based phytoplankton chlorophyll fluorescence. The three dominant factors influencing fluorescence distributions are chlorophyll concentration, pigment packaging effects on light absorption, and light-dependent energy-quenching processes. After accounting for these three factors, resultant global distributions of quenching-corrected fluorescence quantum yields reveal a striking consistency with anticipated patterns of iron availability. High fluorescence quantum yields are typically found in low iron waters, while low quantum yields dominate regions where other environmental factors are most limiting to phytoplankton growth. Specific properties of photosynthetic membranes are discussed that provide a mechanistic view linking iron stress to satellite-detected fluorescence. Our results present satellite-based fluorescence as a valuable tool for evaluating nutrient stress predictions in ocean ecosystem models and give the first synoptic observational evidence that iron plays an important role in seasonal phytoplankton dynamics of the Indian Ocean. Satellite fluorescence may also provide a path for monitoring climate-phytoplankton physiology interactions and improving descriptions of phytoplankton light use efficiencies in ocean productivity models.

302 citations


Authors

Showing all 5752 results

NameH-indexPapersCitations
Roberto Romero1511516108321
Jerry M. Melillo13438368894
Timothy J. Mitchison13340466418
Xiaoou Tang13255394555
Jillian F. Banfield12756260687
Matthew Jones125116196909
Rodolfo R. Llinás12038652828
Ronald D. Vale11734249020
Scott C. Doney11140659218
Alan G. Marshall107106046904
Peter K. Smith10785549174
Donald E. Canfield10529843270
Edward F. DeLong10226242794
Eric A. Davidson10128145511
Gary G. Borisy10124838195
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202357
2022126
2021712
2020701
2019737
2018612