Midwater fish data report for warm-core Gulf Stream rings cruises 1981-1982

This data report is for midwater fishes collected during the multidisciplinary Warm-Core Rings Program in 1981 and 1982. Stations were made in and near three warm-core rings on five cruises within a period of 14 months. On Atlantis II cruise 110 (September-October 1981) six stations were made in and around ring 81-D (age two months). Stations were made in the vicinity of ring 82-B on three cruises in 1982--twelve stations during Oceanus 118 (April) when the ring was two months old, 15 stations during Oceanus 121 (June) at age four months, and 19 stations during Oceanus 125 (August) at age 5.5 months. Finally, twelve stations were made in and near meander/ring 82-H (age 0) during Knorr 98 in September/October 1982 (Tables 1-10). The collections were made with a new midwater trawl - the MOCNESS-20 (MOC-20) (Wiebe et al., 1985), a scaled-up version of the MOCNESS-1 (an apparatus for collecting zooplankton; Wiebe et al., 1976) and successor to the MOCNESS-10 (like the MOC-20, a midwater trawl). (The number forming the distinctive part of the name of these nets is equal to the area of the projected mouth in square meters when the apparatus is in a common fishing attitude.) The MOC-20 consists of a set of 3-mm mesh rectangular nets that can be opened and closed by command from the surface via a signal-conducting towing warp. Apparatus attached to the net frame measures and transmits depth, temperature, conductivity, flow, and net-frame angle to the towing ship's laboratory. Flow (net speed), vertical velocity, and net-frame angle allow computation of the water volume filtered . On the WCR cruises a set of five or six nets was used. One net (not used for quantitative analyses) was fished down to 1000 m, then closed and a second net opened. The second and successive nets were closed and opened sequentially at intervals as the apparatus was brought back to the surface. A surface-to-surface cycle with the gear is referred to as a station, the contents of a single net as a collection. In addition to be1ng described by latitude and longitude, stat1ons are located in the same radial coordinate system used to composite the warm-core rings physical data, that is, by distance and bearing from the moving ring center.Funding was provided by the National Scten.ce Foundation under Grant Numbers OCE 80-17270 and OCE 86-20402

Ceratoscopelus maderensis : pecular sound-scattering layer identified with this myctophid fish

Reprint. Science, vol. 160, no. 3831, 1968, pp. 991-993. Originally issued as Reference No. 68-58, series later renamed WHOI-.A sound- scattering layer, composed of discrete hyperbolic echo-sequences and apparently restricted to the Slope Water region of the western North Atlantic, has been identified from the Deep Submergence Research Vehicle ALVIN with schools of the myctophid fish Ceratoscopelus maderensis. By diving into the layer and using ALVIN's echo-ranging sonar, we approached and visually identified the sound scatterers. The number of echo sequences observed with the surface echo-sounder (1 /23. 76 x 105 cubic meters of water) checked roughly with the number of sonar targets observed from the submarine (1/7. 45 x 105 cubic meters) . The fish schools appeared to be 5 to 10 meters thick, 10 to 100 meters in diameter, and on centers 100 to 200 meters apart. Density within schools was estimated at 10 to 15 fish per cubic meter.Supported in part by contracts Nonr-3484(00) and Nonr-4029(00) and by NSF grant GB-4431

Georges Bank

© The Author(s), 1987. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Backus, Richard H. (1987). Georges Bank. Massachusetts Institute of Technology.Georges Bank provides a basic and indispensable reference tool for anyone involved in studying the bank or in making decisions about its use. Until now debates about alternative uses of the bank have been hampered by the fact that much of the basic research has been available only to specialists and has been scattered among many publications. In bringing the available information on this complex region together for the first time, Georges Bank provides a basic and indispensable reference tool for anyone involved in studying the bank or in making decisions about its use. Moreover, the depth and clarity of the book's 57 articles and 8 nontechnical introductions will make it useful for anyone involved in oceanographic or ocean policy studies.Sections cover all aspects of this huge marine ecosystem - geology, weather and climate, physical oceanography, chemistry, phytoplankton, primary production, zoology and secondary production, the fisheries, and conflicting uses. Georges Bank is the first major project of the Coastal Research Center of Woods Hole Oceanographic Institution. The editor-in-chief, Richard H. Backus, is chairman of the Institutions's biology department. Includes 176 six-color maps, 54 four-color illustrations - 392 charts, graphs, and drawings

New Interstellar Dust Models Consistent with Extinction, Emission, and Abundance Constraints

We present new interstellar dust models which have been derived by simultaneously fitting the far-ultraviolet to near-infrared extinction, the diffuse infrared (IR) emission and, unlike previous models, the elemental abundance constraints on the dust for different interstellar medium abundances, including solar, F and G star, and B star abundances. The fitting problem is a typical ill-posed inversion problem, in which the grain size distribution is the unknown, which we solve by using the method of regularization. The dust model contains various components: PAHs, bare silicate, graphite, and amorphous carbon particles, as well as composite particles containing silicate, organic refractory material, water ice, and voids. The optical properties of these components were calculated using physical optical constants. As a special case, we reproduce the Li & Draine (2001) results, however their model requires an excessive amount of silicon, magnesium, and iron to be locked up in dust: about 50 ppm (atoms per million of H atoms), significantly more than the upper limit imposed by solar abundances of these elements, about 34, 35, and 28 ppm, respectively. A major conclusion of this paper is that there is no unique interstellar dust model that simultaneously fits the observed extinction, diffuse IR emission, and abundances constraints.Comment: 70 pages, 23 figures, accepted for publication in the Astrophysical Journal Supplemen

Interdisciplinary study of warm core ring physics, chemistry, and biology

We are conducting an interdisciplinary study of the structure and dynamics of Gulf Stream \Warm Core Rings by a time series investigation of selected rings. This program consists of highly integrated components which include physical, chemical, and biological investigation and modeling studies. These components are designed to provide information on the structure of rings and exchange mechanisms at ring boundaries, on their marine chemistry, and on the environmental controls of biological activity of selected constituents associated with Warm Core Rings. This research is being conducted by approximately two dozen investigators from thirteen marine institutions. An interdisciplinary program of the scope proposed is required in order to understand the interdependence among biological, chemical, and physical processes in the ocean. This study of the structure and evolution of Warm Core Rings will enhance the understanding of fundamental oceanic processes and the role of rings in the region where they occur

Helioseismic analysis of the hydrogen partition function in the solar interior

The difference in the adiabatic gradient gamma_1 between inverted solar data and solar models is analyzed. To obtain deeper insight into the issues of plasma physics, the so-called ``intrinsic'' difference in gamma_1 is extracted, that is, the difference due to the change in the equation of state alone. Our method uses reference models based on two equations of state currently used in solar modeling, the Mihalas-Hummer-Dappen (MHD) equation of state, and the OPAL equation of state (developed at Livermore). Solar oscillation frequencies from the SOI/MDI instrument on board the SOHO spacecraft during its first 144 days in operation are used. Our results confirm the existence of a subtle effect of the excited states in hydrogen that was previously studied only theoretically (Nayfonov & Dappen 1998). The effect stems from internal partition function of hydrogen, as used in the MHD equation of state. Although it is a pure-hydrogen effect, it takes place in somewhat deeper layers of the Sun, where more than 90% of hydrogen is ionized, and where the second ionization zone of helium is located. Therefore, the effect will have to be taken into account in reliable helioseismic determinations of the astrophysically relevant helium-abundance of the solar convection zone.Comment: 30 pages, 4 figures, 1 table. Revised version submitted to Ap

The vascular flora of Falmouth (Barnstable County) Massachusetts

With a few exceptions, the species on this list of Falmouth vascular plants are substantiated by herbarium sheets, most of which are in the MBLWHOI Library Herbarium (SPWH). We invite improvements to the list by the elimination of errors and by the collection of Falmouth species not yet found. About 880 taxa are listed here, which is about 60% of Barnstable County’s 1440 or so as shown by the County Checklist (Cullina et al. 2011). Barnstable County is a geographically diverse place and not all of its vascular plants are to be expected for any one of its towns, but it seems likely that some dozens of the County’s 560 taxa not yet recorded for Falmouth are to be found in that place. We hope interested field botanists will endeavor to find these “missing” plants, collecting material so that herbarium sheets can be made for deposit in SPWH and their names added to this list. There are also many plants that have not been collected in Falmouth for many years. Material for herbarium sheets is desired for these taxa as well

Mesopelagic fishes in Gulf Stream cold-core rings

Calculations of abundance of midwater fishes in the families Myctophidae, Gonostomatidae, Photichthyidae, and Stemoptychidae for the 1000 m water column were made in cold-core rings and in the nearby Sargasso Sea and Slope Water…

The concentrating of organisms at fronts: A cold-water fish and a warm-core Gulf Stream ring

Net hauls made in and around a warm-core Gulf Stream ring in April and June 1982 suggest a concentrating of the mesopelagic fish Benthosema glaciale (family Myctophidae) in the frontal zone at the east edge of the ring. In April, Benthosema was found in very small numbers in the two-month old ring, as was to be expected from the subpolar-temperate distribution of this fish and the warm-water origin and age of the ring. By June, age-0 fish had been recruited to the population susceptible to capture by the midwater trawl. These young fish were about five times as abundant at the frontal zone of the ring and about twice as abundant in the ring center as in the adjacent Slope Water. It is proposed that the increased abundance at the ring front results from a concentrating of the original Slope Water population by convergence. The increase of B. glaciale in the center of the ring may be associated with the inwardly spiralling streamers observed in satellite images.A simple advection/diffusion model for both the fish and a passive tracer of the fluid is used to consider a mechanism that might have concentrated the fish at the ring edge. It is assumed that the fish can counter the vertical flow in order to maintain their preferred depth. Swimming in the horizontal is assumed to be random. The result of this behavior is that the fish and the passive tracer are affected differently in flow fields such as those in rings. Solutions to the model equations lead to the conclusion that the abundance of fish at the ring front can be accounted for by convergence. The model and the divergence pattern in the ring, calculated from hydrographic data, show the time necessary to effect the hundred-fold increase in abundance that was observed in the ring front between April and June to be on the order of two weeks to a month. We suggest that the concentrating mechanism described is widely applicable to a variety of frontal phenomena and to a variety of planktonic plants and animals