Now showing items 471-490 of 988

    • Iron in the Sargasso Sea (Bermuda Atlantic Time-series Study region) during summer : eolian imprint, spatiotemporal variability, and ecological implications 

      Sedwick, Peter N.; Church, Thomas M.; Bowie, Andrew R.; Marsay, Christopher M.; Ussher, Simon J.; Achilles, K. M.; Lethaby, P. J.; Johnson, Rodney J.; Sarin, M. M.; McGillicuddy, Dennis J. (American Geophysical Union, 2005-10-13)
      We report iron measurements for water column and aerosol samples collected in the Sargasso Sea during July-August 2003 (summer 2003) and April-May 2004 (spring 2004). Our data reveal a large seasonal change in the dissolved ...
    • Iron supply and demand in an Antarctic shelf ecosystem 

      McGillicuddy, Dennis J.; Sedwick, Peter N.; Dinniman, M. S.; Arrigo, Kevin R.; Bibby, Thomas S.; Greenan, Blair J. W.; Hofmann, Eileen E.; Klinck, John M.; Smith, Walker O.; Mack, S. L.; Marsay, Christopher M.; Sohst, Bettina M.; van Dijken, Gert L. (John Wiley & Sons, 2015-10-08)
      The Ross Sea sustains a rich ecosystem and is the most productive sector of the Southern Ocean. Most of this production occurs within a polynya during the November–February period, when the availability of dissolved iron ...
    • Is biological productivity enhanced at the New England shelfbreak front? 

      Zhang, Weifeng G.; McGillicuddy, Dennis J.; Gawarkiewicz, Glen G. (John Wiley & Sons, 2013-01-31)
      A two-dimensional (cross-shelf) numerical model of the mean seasonal circulation offshore of southern New England predicts upwelling at the shelfbreak front. Expected ramifications of this upwelling include enhancement of ...
    • iSAM2 : incremental smoothing and mapping using the Bayes tree 

      Kaess, Michael; Johannsson, Hordur; Roberts, Richard; Ila, Viorela; Leonard, John J.; Dellaert, Frank (2011-04-06)
      We present a novel data structure, the Bayes tree, that provides an algorithmic foundation enabling a better understanding of existing graphical model inference algorithms and their connection to sparse matrix factorization ...
    • Isolating the hydrodynamic triggers of the dive response in eastern oyster larvae 

      Wheeler, Jeanette D.; Helfrich, Karl R.; Anderson, Erik J.; Mullineaux, Lauren S. (John Wiley & Sons, 2015-05-06)
      Understanding the behavior of larval invertebrates during planktonic and settlement phases remains an open and intriguing problem in larval ecology. Larvae modify their vertical swimming behavior in response to water column ...
    • The Jason II virtual control van system, data acquisition system, web-based event logger, and SeaNet 

      Lerner, Steven A.; Maffei, Andrew R. (Woods Hole Oceanographic Institution, 2002-12)
      Scientific underwater remotely operated vehicles (ROVs) collect data from multiple video cameras and scientific instruments. This integrated information is often only available in an ROV control-van during operations. ...
    • The JASON remotely operated vehicle system 

      Ballard, Robert D. (Woods Hole Oceanographic Institution, 1993-02)
      The JASON remotely operated vehicle (ROV) system has been under development for the last decade. After a number of engineering test cruises, including the discovery of the R.M.S. Titanic and the German Battleship Bismarck, ...
    • K-distribution fading models for Bayesian estimation of an underwater acoustic channel 

      Laferriere, Alison Beth (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2011-02)
      Current underwater acoustic channel estimation techniques generally apply linear MMSE estimation. This approach is optimal in a mean square error sense under the assumption that the impulse response fluctuations are well ...
    • The Kallisti Limnes, carbon dioxide-accumulating subsea pools 

      Camilli, Richard; Nomikou, Paraskevi; Escartin, Javier E.; Ridao, Pere; Mallios, Angelos; Kilias, Stephanos P.; Argyraki, Ariadne; Andreani, Muriel; Ballu, Valerie; Campos, Ricard; Deplus, Christine; Gabsi, Taoufic; Garcia, Rafael; Gracias, Nuno; Hurtos, Natalia; Magi, Lluis; Mevel, Catherine; Moreira, Manuel; Palomeras, Narcis; Pot, Olivier; Ribas, David; Ruzie, Lorraine; Sakellariou, Dimitris (Nature Publishing Group, 2015-07-16)
      Natural CO2 releases from shallow marine hydrothermal vents are assumed to mix into the water column, and not accumulate into stratified seafloor pools. We present newly discovered shallow subsea pools located within the ...
    • Kalman filter estimation of underwater vehicle position and attitude using Doppler velocity aided inertial motion unit 

      Leader, Daniel Eugene (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1994-09)
      This Paper explores the use of an extended Kalman filter to provide real-time estimates of underwater vehicle position and attitude. The types of previously available sensors are detailed including strapdown accelerometers, ...
    • Kinematic evaluation of end effector design 

      Edwards, Gary W. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1992-09)
      The complex, many degree-of-freedom end effectors at the leading edge of technology would be unusable in the sea bottom research environment. Simpler designs are required to provide adequate reliability for subsea ...
    • Laboratory evaluation of laser-induced breakdown spectroscopy (LIBS) as a new in situ chemical sensing technique for the deep ocean 

      Michel, Anna P. M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2007-09)
      Present-day expeditionary oceanography is beginning to shift from a focus on short- term ship and submersible deployments to an ocean observatory mode where long- term temporally-focused studies are feasible. As a result, ...
    • Laboratory measurements of high-frequency, acoustic broadband backscattering from sea ice and crude oil 

      Bassett, Christopher; Lavery, Andone C.; Maksym, Ted; Wilkinson, Jeremy P. (Acoustical Society of America, 2014-12-18)
      Recent decreases in summer sea ice cover are spurring interest in hydrocarbon extraction and shipping in Arctic waters, increasing the risk of an oil spill in ice covered waters. With advances in unmanned vehicle operation, ...
    • Laboratory measurements of the sound generated by breaking waves 

      Loewen, Mark Richard (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1991-12)
      Breaking waves dissipate energy, transfer momentum from the wind to surface currents and breaking enhances the transfer of gas and mass across the air-sea interface. Breaking waves are believed to be the dominant source ...
    • Laboratory observations of double-diffusive convection using high-frequency broadband acoustics 

      Ross, Tetjana; Lavery, Andone C. (2008-09)
      High-frequency broadband (200-300 kHz) acoustic scattering techniques have been used to observe the diffusive regime of double-diffusive convection in the laboratory. Pulse compression signal processing techniques allow ...
    • 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 ...