Woods Hole Oceanographic Institution

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.

Deep convection in the Irminger Sea forced by the Greenland tip jet

Abstract: Open-ocean deep convection, one of the processes by which deep waters of the world's oceans are formed, is restricted to a small number of locations (for example, the Mediterranean and Labrador seas). Recently, the southwest Irminger Sea has been suggested as an additional location for open-ocean deep convection. The deep water formed in the Irminger Sea has the characteristic temperature and salinity of the water mass that fills the mid-depth North Atlantic Ocean, which had been believed to be formed entirely in the Labrador basin. Here we show that the most likely cause of the convection in the Irminger Sea is a low-level atmospheric jet known as the Greenland tip jet, which forms periodically in the lee of Cape Farewell, Greenland, and is associated with elevated heat flux and strong wind stress curl. Using a history of tip-jet events derived from meteorological land station data and a regional oceanic numerical model, we demonstrate that deep convection can occur in this region when the North Atlantic Oscillation Index is high, which is consistent with observations. This mechanism of convection in the Irminger Sea differs significantly from those known to operate in the Labrador and Mediterranean seas.

Species boundaries and global biogeography of the Alexandrium tamarense complex (Dinophyceae).

Abstract: Alexandrium catenella (Whedon et Kof.) Balech, A. tamarense (M. Lebour) Balech, and A. fundyense Balech comprise the A. tamarense complex, dinoflagellates responsible for paralytic shellfish poisoning worldwide. The relationships among these morphologically defined species are poorly understood, as are the reasons for increases in range and bloom occurrence observed over several decades. This study combines existing data with new ribosomal DNA sequences from strains originating from the six temperate continents to reconstruct the biogeography of the complex and explore the origins of new populations. The morphospecies are examined under the criteria of phylogenetic, biological, and morphological species concepts and do not to satisfy the requirements of any definition. It is recommended that use of the morphospecies appellations within this complex be discontinued as they imply erroneous relationships among morphological variants. Instead, five groups (probably cryptic species) are identified within the complex that are supported on the basis of large genetic distances, 100% bootstrap values, toxicity, and mating compatibility. Every isolate of three of the groups that has been tested is nontoxic, whereas every isolate of the remaining two groups is toxic. These phylogenetic groups were previously identified within the A. tamarense complex and given geographic designations that reflected the origins of known isolates. For at least two groups, the geographically based names are not indicative of the range occupied by members of each group. Therefore, we recommend a simple group-numbering scheme for use until the taxonomy of this group is reevaluated and new species are proposed.

Nitrospira marina gen. nov. sp. nov.: a chemolithotrophic nitrite-oxidizing bacterium

Abstract: A new chemolithotrophic nitrite-oxidizing bacterium, for which the name Nitrospira marina is proposed, was isolated from the Gulf of Maine N marina is a Gramnegative curved rod which may form spirals with 1 to 12 turns Cells have a unique periplasmic space and lack intracytoplasmic membranes and carboxysomes N marina is an obligate chemolithotroph, but best growth is obtained in a mixotrophic medium N marina may be one of the most prevalent nitrite-oxidizing bacteria in some oceanic environments Type strain is field with American Type Culture Collection (ATCC 43039)

Form of the Temperature-Salinity Relationship in the Central Water: Evidence for Double-Diffusive Mixing

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,...