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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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TL;DR: In this paper, the authors used the most recent simulations performed in the framework of the Coupled Model Intercomparison Project 5 to assess how these stressors may evolve over the course of the 21st century.
Abstract: Ocean ecosystems are increasingly stressed by human-induced changes of their physical, chemical and biological environment. Among these changes, warming, acidification, deoxygenation and changes in primary productivity by marine phytoplankton can be considered as four of the major stressors of open ocean ecosystems. Due to rising atmospheric CO 2 in the coming decades, these changes will be amplified. Here, we use the most recent simulations performed in the framework of the Coupled Model Intercomparison Project 5 to assess how these stressors may evolve over the course of the 21st century. The 10 Earth system models used here project similar trends in ocean warming, acidification, deoxygenation and reduced primary productivity for each of the IPCC's representative concentration pathways (RCPs) over the 21st century. For the "business-as-usual" scenario RCP8.5, the model-mean changes in the 2090s (compared to the 1990s) for sea surface temperature, sea surface pH, global O 2 content and integrated primary productivity amount to p2.73 (±0.72) °C, −0.33 (±0.003) pH unit, −3.45 (±0.44)% and −8.6 (±7.9)%, respectively. For the high mitigation scenario RCP2.6, corresponding changes are +0.71 (±0.45) °C, −0.07 (±0.001) pH unit, −1.81 (±0.31)% and −2.0 (±4.1)%, respectively, illustrating the effectiveness of extreme mitigation strategies. Although these stressors operate globally, they display distinct regional patterns and thus do not change coincidentally. Large decreases in O 2 and in pH are simulated in global ocean intermediate and mode waters, whereas large reductions in primary production are simulated in the tropics and in the North Atlantic. Although temperature and pH projections are robust across models, the same does not hold for projections of subsurface O 2 concentrations in the tropics and global and regional changes in net primary productivity. These high uncertainties in projections of primary productivity and subsurface oxygen prompt us to continue inter-model comparisons to understand these model differences, while calling for caution when using the CMIP5 models to force regional impact models.

1,147 citations

Journal ArticleDOI
13 Dec 2002-Science
TL;DR: In this paper, a decade-long soil warming experiment in a mid-latitude hardwood forest, documented changes in soil carbon and nitrogen cycling in order to investigate the consequences of these changes for the climate system, and showed that whereas soil warming accelerates soil organic matter decay and carbon dioxide fluxes to the atmosphere, this response is small and short-lived for a midlatitude forest, because of the limited size of the labile soil carbon pool.
Abstract: In a decade-long soil warming experiment in a mid-latitude hardwood forest, we documented changes in soil carbon and nitrogen cycling in order to investigate the consequences of these changes for the climate system. Here we show that whereas soil warming accelerates soil organic matter decay and carbon dioxide fluxes to the atmosphere, this response is small and short-lived for a mid-latitude forest, because of the limited size of the labile soil carbon pool. We also show that warming increases the availability of mineral nitrogen to plants. Because plant growth in many mid-latitude forests is nitrogen-limited, warming has the potential to indirectly stimulate enough carbon storage in plants to at least compensate for the carbon losses from soils. Our results challenge assumptions made in some climate models that lead to projections of large long-term releases of soil carbon in response to warming of forest ecosystems.

1,141 citations

Journal ArticleDOI
TL;DR: DGGE analysis of PCR-amplified 16S rDNA fragments was used to explore the genetic diversity of hydrothermal vent microbial communities, specifically to determine the importance of sulfur-oxidizing bacteria therein, and identified three ‘phylotypes’ which represented a newThiomicrospira species, phylogenetically in an intermediate position between Tms.
Abstract: Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rDNA fragments was used to explore the genetic diversity of hydrothermal vent microbial communities, specifically to determine the importance of sulfur-oxidizing bacteria therein. DGGE analysis of two different hydrothermal vent samples revealed one PCR band for one sample and three PCR bands for the other sample, which probably correspond to the dominant bacterial populations in these communities. Three of the four 16S rDNA fragments were sequenced. By comparison with 16S rRNA sequences of the Ribosomal Database Project, two of the DGGE-separated fragments were assigned to the genus Thiomicrospira. To identify these 'phylotypes' in more detail, a phylogenetic framework was created by determining the nearly complete 16S rRNA gene sequence (approx. 1500 nucleotides) from three described Thiomicrospira species, viz., Tms. crunogena, Tms. pelophila, Tms. denitrificans, and from a new isolate, Thiomicrospira sp. strain MA2-6. All Thiomicrospira species except Tms. denitrificans formed a monophyletic group within the gamma subdivision of the Proteobacteria. Tms. denitrificans was assigned as a member of the epsilon subdivision and was distantly affiliated with Thiovulum, another sulfur-oxidizing bacterium. Sequences of two dominant 16S rDNA fragments obtained by DGGE analysis fell into the gamma subdivision Thiomicrospira. The sequence of one fragment was in all comparable positions identical to the 16S rRNA sequence of Tms. crunogena. Identifying a dominant molecular isolate as Tms. crunogena indicates that this species is a dominant community member of hydrothermal vent sites. Another 'phylotype' represented a new Thiomicrospira species, phylogenetically in an intermediate position between Tms. crunogena and Tms. pelophila. The third 'phylotype' was identified as a Desulfovibrio, indicating that sulfate-reducing bacteria, as sources of sulfide, may complement sulfur- and sulfide-oxidizing bacteria ecologically in these sulfide-producing hydrothermal vents.

1,135 citations

Journal ArticleDOI
TL;DR: In this paper, the authors studied the geophysical beta-effect of two-dimensional eddies in a homogeneous fluid at large Reynolds number, and showed that when the energy is intermittent in space, the cascade is halted simply by the spreading of energy about space, and then the end state of a zonal flow is probably not achieved.
Abstract: Two-dimensional eddies in a homogeneous fluid at large Reynolds number, if closely packed, are known to evolve towards larger scales. In the presence of a restoring force, the geophysical beta-effect, this cascade produces a field of waves without loss of energy, and the turbulent migration of the dominant scale nearly ceases at a wavenumber kβ = (β/2U)½ independent of the initial conditions other than U, the r.m.s. particle speed, and β, the northward gradient of the Coriolis frequency.The conversion of turbulence into waves yields, in addition, more narrowly peaked wavenumber spectra and less fine-structure in the spatial maps, while smoothly distributing the energy about physical space.The theory is discussed, using known integral constraints and similarity solutions, model equations, weak-interaction wave theory (which provides the terminus for the cascade) and other linearized instability theory. Computer experiments with both finite-difference and spectral codes are reported. The central quantity is the cascade rate, defined as \[ T = 2\int_0^{\infty} kF(k)dk/U^3\langle k\rangle , \] where F is the nonlinear transfer spectrum and 〈k〉 the mean wavenumber of the energy spectrum. (In unforced inviscid flow T is simply U−1d〈k〉−1/dt, or the rate at which the dominant scale expands in time t.) T is shown to have a mean value of 3·0 × 10−2 for pure two-dimensional turbulence, but this decreases by a factor of five at the transition to wave motion. We infer from weak-interaction theory even smaller values for k [Lt ] kβ.After passing through a state of propagating waves, the homogeneous cascade tends towards a flow of alternating zonal jets which, we suggest, are almost perfectly steady. When the energy is intermittent in space, however, model equations show that the cascade is halted simply by the spreading of energy about space, and then the end state of a zonal flow is probably not achieved.The geophysical application is that the cascade of pure turbulence to large scales is defeated by wave propagation, helping to explain why the energy-containing eddies in the ocean and atmosphere, though significantly nonlinear, fail to reach the size of their respective domains, and are much smaller. For typical ocean flows, . In addition the cascade generates, by itself, zonal flow (or more generally, flow along geostrophic contours).

1,124 citations

Journal ArticleDOI
TL;DR: In this article, the transform fault concept is extended to a spherical surface, where the motion of one block relative to another block may then be described by a rotation of a rigid crustal blocks relative to the other block.
Abstract: The transform fault concept is extended to a spherical surface. The earth's surface is considered to be made of a number of rigid crustal blocks. It is assumed that each block is bounded by rises (where new surface is formed), trenches or young fold mountains (where surface is being destroyed), and great faults, and that there is no stretching, folding, or distortion of any kind within a given block. On a spherical surface, the motion of one block (over the mantle) relative to another block may then be described by a rotation of one block relative to the other block. This rotation requires three parameters, two to locate the pole of relative rotation and one to specify the magnitude of the angular velocity. If two adjacent blocks have as common boundaries a number of great faults, all of these faults must lie on ‘circles of latitude’ about the pole of relative rotation. The velocity of one block relative to the other must vary along their common boundary; this velocity would have a maximum at the ‘equator’ and would vanish at a pole of relative rotation. The motion of Africa relative to South America is a case for which enough data are available to critically test this hypothesis. The many offsets on the mid-Atlantic ridge appear to be compatible with a pole of relative rotation at 62°N (±5°), 36°W (±2°). The velocity pattern predicted by this choice of pole roughly agrees with the spreading velocities determined from magnetic anomalies. The motion of the Pacific block relative to North America is also examined. The strike of faults from the Gulf of California to Alaska and the angles inferred from earthquake mechanism solutions both imply a pole of relative rotation at 53°N (±3°), 53°W (±5°). The spreading of the Pacific-Antarctic ridge shows the best agreement with this hypothesis. The Antarctic block is found to be moving relative to the Pacific block about a pole at 71°S (±2°), 118°E (±5°) with a maximum spreading rate of 5.7 (±0.2) cm/yr. An estimate of the motion of the Antarctic block relative to Africa is made by assuming closure of the Africa-America-Pacific-Antarctica-Africa circuit and summing the three angular velocity vectors for the cases above.

1,106 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