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Filtering by: Publisher American Vacuum Society Remove constraint Publisher: American Vacuum Society Decade 1980-1989 Remove constraint Decade: 1980-1989

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  • Uncertainties and Speculations About the Life Cycle of the Eastern Oyster Pathogen Haplosporidium nelsoni (MSX)

    Creator:
    Haskin, Harold H. and Andrews, Jay D.
    Abstract:
    For 30 years, the pathogen Haplosporidium nelsoni (MSX) has been causing serious mortalities of eastern oysters Crassostrea virginica in the Delaware and Chesapeake bays. Its life cycle is largely unknown, and methods for control are wanting. Breeding of resistant eastern oyster strains, at this time, offers the best hope for...
    Resource Type:
    Article

  • Management strategies to control the disease caused by Perkinsus marinus

    Creator:
    Andrews, Jay D. and Ray, Sammy M.
    Abstract:
    Perkinsus marinus is a warm-season protozoan pathogen (Phylum Apicomplexa) that parasitizes eastern oysters Crassostrea virginica from Chesapeake Bay to the Gulf of Mexico. In years of normal rainfall in Chesapeake Bay, P. marinus is limited by low salinities in the estuaries and is dormant during winter and spring. A few...
    Resource Type:
    Article

  • The Dependence of Boundary-Layer Shear on Diurnal Variation of Stability

    Creator:
    Heald, R. C. and Mahrt, L.
    Abstract:
    Boundary-layer data from several different geographical locations are analyzed to document the behavior of boundary-layer shear above the surface. The influence of diurnal variation of stability is emphasized. The applicability of the power law for use in shear estimates is examined.
    Resource Type:
    Article

  • Grid-Averaged Surface Fluxes

    Creator:
    Mahrt, L.
    Abstract:
    This study examines the inadequacies of formulations for surface fluxes for use in numerical models of atmospheric flow. The difficulty is that numerical models imply spatial averaging over each grid area. Existing formulations am based on the relationship between local fluxes and local gradients and appear to describe the relationship...
    Resource Type:
    Article

  • Limit Cycle Mixing

    Creator:
    Mahrt, L.
    Abstract:
    Lagrangian equations for momentum and buoyancy are developed for idealized turbulent fluid elements. The resulting formulation of transport can he viewed as a generalization of mixing length and parcel theories of mixing for application to gridded Eulerian models. This formulation of transport recognizes the mean gradients on the scale of...
    Resource Type:
    Article

  • Vertical Structure and Turbulence in the Very Stable Boundary Layer

    Creator:
    Mahrt, L.
    Abstract:
    The structure of turbulence in a strongly stratified nocturnal boundary layer is studied using fast-response aircraft data collected under clear sky conditions with weak ambient flow. The principal source of turbulence is shear generation near the top of the surface inversion layer. This shear is induced by the development of...
    Resource Type:
    Article

  • A Study of Boundary-Layer Pressure Adjustments

    Creator:
    Smith, Bartlett and Mahrt, L.
    Abstract:
    An analytical two-layer approximation of atmospheric flow is developed to study boundary-layer production of vertical motion. The model consists of a boundary layer topped by a free-flow layer. Both layers am time-dependent and possess different values of stratification. The boundary-layer equations are layer-integrated over a fixed depth and surface stress...
    Resource Type:
    Article

  • Small-Scale Sea Surface Temperature Structure

    Creator:
    Simpson, James J. and Paulson, Clayton A.
    Abstract:
    Observations of sea surface temperature and wave height were made from a large, manned spar buoy (R/P FLIP) ~100 km off the coast of Baja California. Surface temperature was measured with a radiation thermometer which viewed a disc on the surface 12 cm in diameter. The instrument responded to frequencies...
    Resource Type:
    Article

  • Quasi-Geostrophic Topographically Generated Mean Flow over the Continental Margin

    Creator:
    Samelson, Roger M. and Allen, J. S.
    Abstract:
    Observations of oppositely directed, monthly mean alongshore currents and wind stress over the continental margin off the Pacific coast of North America motivate the theoretical examination of mean flow generation by topographic lee-wave drag. We formulate a barotropic model for wind-forced shelf-slope flow over variable topography. Our central objective is...
    Resource Type:
    Article

  • Heat and Energy Balances in the Upper Ocean at 50°N, 140°W during November 1980 (STREX)

    Creator:
    Paduan, S. D. and DeSzoeke, R. A.
    Abstract:
    Subsurface temperature data and surface meteorological data are analyzed from thermistor chain moorings deployed near 50°N, 140°W during the Storm Transfer and Response Experiment (STREX). The upper-ocean heat and potential energy (PE) contents to 90 m are examined for an 18-day period and their changes compared to the sources and...
    Resource Type:
    Article