Now showing items 471-490 of 938

    • The landward and seaward mechanisms of fine-sediment transport across intertidal flats in the shallow-water region—A numerical investigation 

      Hsu, Tian-Jian; Chen, Shih-Nan; Ogston, Andrea S. (2011-03-15)
      This study investigates transport of fine sediment across idealized intertidal flats with emphasis on resolving processes at the tidal edge, which is defined as the very shallow region of the land-water interface. We first ...
    • Large-area visually augmented navigation for autonomous underwater vehicles 

      Eustice, Ryan M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2005-06)
      This thesis describes a vision-based, large-area, simultaneous localization and mapping (SLAM) algorithm that respects the low-overlap imagery constraints typical of autonomous underwater vehicles (AUVs) while exploiting ...
    • Large-eddy simulation of the tidal-cycle variations of an estuarine boundary layer 

      Li, Ming; Radhakrishnan, Senthilkumaran; Piomelli, Ugo; Geyer, W. Rockwell (American Geophysical Union, 2010-08-03)
      The estuarine boundary layer affected by a horizontal density gradient exhibits temporal evolution over a tidal cycle, in a manner similar to the diurnal cycle of the ocean surface mixed layer. A large eddy simulation (LES) ...
    • Larval dispersion along an axially symmetric mid-ocean ridge 

      McGillicuddy, Dennis J.; Lavelle, J. William; Thurnherr, Andreas M.; Kosnyrev, V. K.; Mullineaux, Lauren S. (2009-12-22)
      We investigated planktonic larval transport processes along an axially symmetric mid-ocean ridge with characteristics similar to that of the East Pacific Rise (EPR) segment at 9-10°N. The hydrodynamic basis for this study ...
    • Laser diffraction particle sizing : sampling and inversion 

      Riley, James B. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1987-08-13)
      The inverse problem of obtaining particle size distributions from observations of the angular distribution of near forward scattered light is reexamined. Asymptotic analysis of the forward problem reveals the ...
    • Laser Raman spectroscopy as a technique for identification of seafloor hydrothermal and cold seep minerals 

      White, Sheri N. (2008-11)
      In situ sensors capable of real-time measurements and analyses in the deep ocean are necessary to fulfill the potential created by the development of autonomous, deep-sea platforms such as autonomous and remotely operated ...
    • Lateral circulation and sediment transport driven by axial winds in an idealized, partially mixed estuary 

      Chen, Shih-Nan; Sanford, Lawrence P.; Ralston, David K. (American Geophysical Union, 2009-12-03)
      A 3D hydrodynamic model (ROMS) is used to investigate lateral circulation in a partially mixed estuary driven by axial wind events and to explore the associated transport of sediments. The channel is straight with a ...
    • The LatMix summer campaign : submesoscale stirring in the upper ocean 

      Shcherbina, Andrey Y.; Sundermeyer, Miles A.; Kunze, Eric; D’Asaro, Eric; Badin, Gualtiero; Birch, Daniel; Brunner-Suzuki, Anne-Marie E. G.; Callies, Joern; Cervantes, Brandy T. Kuebel; Claret, Mariona; Concannon, Brian; Early, Jeffrey; Ferrari, Raffaele; Goodman, Louis; Harcourt, Ramsey R.; Klymak, Jody M.; Lee, Craig M.; Lelong, M.-Pascale; Levine, Murray D.; Lien, Ren-Chieh; Mahadevan, Amala; McWilliams, James C.; Molemaker, M. Jeroen; Mukherjee, Sonaljit; Nash, Jonathan D.; Ozgokmen, Tamay M.; Pierce, Stephen D.; Ramachandran, Sanjiv; Samelson, Roger M.; Sanford, Thomas B.; Shearman, R. Kipp; Skyllingstad, Eric D.; Smith, K. Shafer; Tandon, Amit; Taylor, John R.; Terray, Eugene A.; Thomas, Leif N.; Ledwell, James R. (American Meteorological Society, 2015-08)
      Lateral stirring is a basic oceanographic phenomenon affecting the distribution of physical, chemical, and biological fields. Eddy stirring at scales on the order of 100 km (the mesoscale) is fairly well understood and ...
    • Length scale of the finite-amplitude meanders of shelfbreak fronts 

      Zhang, Weifeng G.; Gawarkiewicz, Glen G. (American Meteorological Society, 2015-10)
      Through combining analytical arguments and numerical models, this study investigates the finite-amplitude meanders of shelfbreak fronts characterized by sloping isopycnals outcropping at both the surface and the shelfbreak ...
    • Lidar and pressure measurements of inner-surfzone waves and setup 

      Brodie, Katherine L.; Raubenheimer, Britt; Elgar, Steve; Slocum, R. K.; McNinch, Jesse E. (American Meteorological Society, 2015-10)
      Observations of waves and setup on a steep, sandy beach are used to identify and assess potential applications of spatially dense lidar measurements for studying inner-surf and swash-zone hydrodynamics. There is good ...
    • Linearity of fisheries acoustics, with addition theorems 

      Foote, Kenneth G. (Acoustical Society of America, 1983-06)
      An experiment to verify the basic linearity of fisheries acoustics is described. Herring (Clupea harengus L.) was the subject fish. Acoustic measurements consisted of the echo energy from aggregations of encaged but otherwise ...
    • Linking glacially modified waters to catchment-scale subglacial discharge using autonomous underwater vehicle observations 

      Stevens, Laura A.; Straneo, Fiamma; Das, Sarah; Plueddemann, Albert J.; Kukulya, Amy L.; Morlighem, Mathieu (Copernicus Publications on behalf of the European Geosciences Union, 2016-02-24)
      Measurements of near-ice (<  200 m) hydrography and near-terminus subglacial hydrology are lacking, due in large part to the difficulty in working at the margin of calving glaciers. Here we pair detailed hydrographic and ...
    • The load/deflection behavior of pretensioned cable/pulley transmission mechanisms 

      Snow, Edward R. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1993-12)
      Mechanical transmission mechanisms enable a designer to match the abilities (e .g. velocity, torque capacity) of an actuator to the needs of an application. Unfortunately the mechanical limitations of the transmission ...
    • LOCOMOOR : a LOw-COst MOORing for the measurement of internal solitary waves 

      Lord, Jeffrey; Irish, James D.; Duda, Timothy F.; Kemp, John N. (2000-05-09)
      In order to supplement the ASIAEX field effort to measure the temporal and spatial structure of the internal solitary wave field in relationship to acoustic propagation and scattering studies, an array of low-cost ...
    • Long distance passive localization of vocalizing sei whales using an acoustic normal mode approach 

      Newhall, Arthur E.; Lin, Ying-Tsong; Lynch, James F.; Baumgartner, Mark F.; Gawarkiewicz, Glen G. (Acoustical Society of America, 2012-02)
      During a 2 day period in mid-September 2006, more than 200, unconfirmed but identifiable, sei whale (Balaenoptera borealis) calls were collected as incidental data during a multidisciplinary oceanography and acoustics ...
    • Long-baseline acoustic navigation for under-ice autonomous underwater vehicle operations 

      Jakuba, Michael V.; Roman, Christopher N.; Singh, Hanumant; Murphy, Christopher A.; Kunz, Clayton G.; Willis, Claire; Sato, Taichi; Sohn, Robert A. (2008-05-19)
      The recent Arctic GAkkel Vents Expedition (AGAVE) to the Arctic Ocean’s Gakkel Ridge (July/August 2007) aboard the Swedish ice-breaker I/B Oden employed autonomous underwater vehicles (AUVs) for water-column and ocean ...
    • Loose-tube neutral tether fiber optic termination procedure 

      Bowen, Martin F. (Woods Hole Oceanographic Institution, 2001-06)
      Neutral tethers for unmanned underwater vehicles may contain a bundle of single-mode, optical fibers that are protected inside flexible stainless steel tubing. To date the author knows of no commercially available systems ...
    • Lossy compression and real-time geovisualization for ultra-low bandwidth telemetry from untethered underwater vehicles 

      Murphy, Christopher A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2008-09)
      Oceanographic applications of robotics are as varied as the undersea environment itself. As underwater robotics moves toward the study of dynamic processes with multiple vehicles, there is an increasing need to distill ...
    • Low complexity lossless compression of underwater sound recordings 

      Johnson, Mark P.; Partan, James W.; Hurst, Thomas P. (Acoustical Society of America, 2013-03)
      Autonomous listening devices are increasingly used to study vocal aquatic animals, and there is a constant need to record longer or with greater bandwidth, requiring efficient use of memory and battery power. Real-time ...
    • Low-frequency bottom backscattering data analysis using multiple constraints beamforming 

      Li, Dan (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1995-05)
      The data analysis of a deep-sea bottom backscattering experiment, carried out over a sediment pond on the western flank of the Mid-Atlantic Ridge in July 1993 with a 250- 650 Hz chirp source and a vertical receiving array ...