Now showing items 243-262 of 957

    • Diapycnal mixing in the Antarctic Circumpolar Current 

      Ledwell, James R.; St. Laurent, Louis C.; Girton, James B.; Toole, John M. (American Meteorological Society, 2011-01)
      The vertical dispersion of a tracer released on a density surface near 1500-m depth in the Antarctic Circumpolar Current west of Drake Passage indicates that the diapycnal diffusivity, averaged over 1 yr and over tens of ...
    • Diel changes in humpback whale Megaptera novaeangliae feeding behavior in response to sand lance Ammodytes spp. behavior and distribution 

      Friedlaender, Ari S.; Hazen, Elliott L.; Nowacek, Douglas P.; Halpin, Patrick N.; Ware, Colin; Weinrich, Mason T.; Hurst, Thomas P.; Wiley, David N. (Inter-Research, 2009-12-03)
      Humpback whales Megaptera novaeangliae have adopted unique feeding strategies to take advantage of behavioral changes in their prey. However, logistical constraints have largely limited ecological analyses of these ...
    • Differences between sound scattering by weakly scattering spheres and finite-length cylinders with applications to sound scattering by zooplankton 

      Stanton, Timothy K.; Wiebe, Peter H.; Chu, Dezhang (Acoustical Society of America, 1998-01)
      A modeling study was conducted to determine the conditions under which fluidlike zooplankton of the same volume but different shapes (spherical/cylindrical) have similar or dramatically different scattering properties. ...
    • A differential pressure instrument with wireless telemetry for in-situ measurement of fluid flow across sediment-water boundaries 

      Gardner, Alan T.; Karam, Hanan N.; Mulligan, Ann E.; Harvey, Charles F.; Hammar, Terence R.; Hemond, Harold F. (Molecular Diversity Preservation International, 2009-01-09)
      An instrument has been built to carry out continuous in-situ measurement of small differences in water pressure, conductivity and temperature, in natural surface water and groundwater systems. A low-cost data telemetry ...
    • Diffuse flow from hydrothermal vents 

      Trivett, D. Andrew (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1991-06)
      The effluent from a collection of diffuse hydrothennal vents was modelled to determine the fate of this source of flow under typical environmental conditions at seafloor spreading centers. A laboratory simulation was ...
    • Diffuse venting at the ASHES hydrothermal field : heat flux and tidally modulated flow variability derived from in situ time-series measurements 

      Mittelstaedt, Eric; Fornari, Daniel J.; Crone, Timothy J.; Kinsey, James C.; Kelley, Deborah S.; Elend, Mitch (John WIley & Sons, 2016-04-27)
      Time-series measurements of diffuse exit-fluid temperature and velocity collected with a new, deep-sea camera, and temperature measurement system, the Diffuse Effluent Measurement System (DEMS), were examined from a fracture ...
    • Digital data logging and processing, Derbyshire Survey, 1997 

      Howland, Jonathan C. (Woods Hole Oceanographic Institution, 1999-07)
      In 1997, the Deep Submergence Group (DSG) of the Woods Hole Oceanographic Institution (WHOI) surveyed the wreckage field of the M.V. Derbyshire. The motivation for the survey and its results are described elsewhere ...
    • Direct estimate of lateral eddy diffusivity upstream of Drake Passage 

      Tulloch, Ross; Ferrari, Raffaele; Jahn, Oliver; Klocker, Andreas; LaCasce, Joseph H.; Ledwell, James R.; Marshall, John C.; Messias, Marie-Jose; Speer, Kevin G.; Watson, Andrew J. (American Meteorological Society, 2014-10)
      The first direct estimate of the rate at which geostrophic turbulence mixes tracers across the Antarctic Circumpolar Current is presented. The estimate is computed from the spreading of a tracer released upstream of Drake ...
    • Direct estimation of the Reynolds stress vertical structure in the nearshore 

      Feddersen, Falk; Williams, Albert J. (American Meteorological Society, 2007-01)
      Measurements of the vertical Reynolds stress components in the wave-dominated nearshore are required to diagnose momentum and turbulence dynamics. Removing wave bias from Reynolds stress estimates is critical to a successful ...
    • Direct numerical simulations of instability and boundary layer turbulence under a solitary wave 

      Ozdemir, Celalettin E.; Hsu, Tian-Jian; Balachandar, S. (Cambridge University Press, 2013-08-28)
      A significant amount of research effort has been made to understand the boundary layer instability and the generation and evolution of turbulence subject to periodic/oscillatory flows. However, little is known about bottom ...
    • Direct-form adaptive equalization for underwater acoustic communication 

      Yellepeddi, Atulya (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2012-06)
      Adaptive equalization is an important aspect of communication systems in various environments. It is particularly important in underwater acoustic communication systems, as the channel has a long delay spread and is ...
    • Directional wavenumber characteristics of short sea waves 

      Suoja, Nicole M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2000-02)
      Interest in short waves on the ocean surface has been growing over the last three decades because they play an important role in surface electromagnetic (e.m.) scattering. Currently radars and scatterometers which use ...
    • Discriminating between the nearfield and the farfield of acoustic transducers 

      Foote, Kenneth G. (Acoustical Society of America, 2014-10)
      Measurements of the performance of acoustic transducers, as well as ordinary measurements made with the same, may require discriminating between the farfield, where the field is spherically divergent, and the complementary ...
    • The dispersal of dense water formed in an idealized coastal polynya on a shallow sloping shelf 

      Zhang, Weifeng G.; Cenedese, Claudia (American Meteorological Society, 2014-06)
      This study examines the dispersal of dense water formed in an idealized coastal polynya on a sloping shelf in the absence of ambient circulation and stratification. Both numerical and laboratory experiments reveal two ...
    • Dispersion of a tracer in the deep Gulf of Mexico 

      Ledwell, James R.; He, Ruoying; Xue, Zuo; DiMarco, Steven; Spencer, Laura J.; Chapman, Piers (John Wiley & Sons, 2016-02-05)
      A 25 km streak of CF3SF5 was released on an isopycnal surface approximately 1100 m deep, and 150 m above the bottom, along the continental slope of the northern Gulf of Mexico, to study stirring and mixing of a passive ...
    • Dispersion of fine particles by wave-induced mass transport near a circular island 

      Womeldorf, Carole A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1993-08)
      We begin with the linearized irrotational theory describing the diffraction of an incoming plane wave by a vertical cylinder. From the free-surface motion, we describe the boundary-layer flow field U0i near that cylinder. ...
    • Dissolved methane distributions and air-sea flux in the plume of a massive seep field, Coal Oil Point, California 

      Mau, Susan; Valentine, David L.; Clark, Jordan F.; Reed, Justin; Camilli, Richard; Washburn, Libe (American Geophysical Union, 2007-11-24)
      Large quantities of natural gas are emitted from the seafloor into the stratified coastal ocean near Coal Oil Point, Santa Barbara Channel, California. Methane was quantified in the down current surface water at 79 stations ...
    • A distributed approach to underwater acoustic communications 

      Bohner, Christopher George (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2003-09)
      A novel distributed underwater acoustic networking (UAN) protocol suitable for ad-hoc deployments of both stationary and mobile nodes dispersed across a relatively wide coverage area is presented. Nodes are dynamically ...
    • Distributed autonomy and formation control of a drifting swarm of autonomous underwater vehicles 

      Rypkema, Nicholas R. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2015-09)
      Recent advances in autonomous underwater vehicle (AUV) technology have led to their wide-spread acceptance and adoption for use in scientific, commercial, and defence applications in the underwater domain. At the same time, ...
    • Distributed space–time cooperative schemes for underwater acoustic communications 

      Vajapeyam, Madhavan; Vedantam, Satish; Mitra, Urbashi; Preisig, James C.; Stojanovic, Milica (IEEE, 2008-10)
      In resource limited, large scale underwater sensor networks, cooperative communication over multiple hops offers opportunities to save power. Intermediate nodes between source and destination act as cooperative relays. ...