Orr Marshall H.

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Orr
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Marshall H.
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  • Technical Report
    Remote acoustic sensing of the particulate phase of industrial chemical wastes and sewage sludge : report on the seasonal variability of the dispersion of the particulate phase as observed from three cruises, July 1977, January-February 1978, and April 1978
    (Woods Hole Oceanographic Institution, 1980-01) Orr, Marshall H. ; Baxter, Lincoln ; Hess, Frederick R.
    The seasonal variability of the dispersion of the particulate phase of industrial chemical waste has been studied with acoustic backscattering techniques at Deep Water Dumpsite 106 (DWD 106). The vertical dispersion of the particulates has been found to be strongly dependent on the depth of the mixed layer and the magnitude of the density gradient associated with the seasonal thermocline. The horizontal dispersion of the particulates as a function of depth has been found to be strongly dependent on the shear present in the water column. Entire waste plumes have been found to be advected out of the dumpsite in less than 24 hours when the area is occupied by a warm core ring. Simple calculations based upon Stoke's law are presented to reveal the impact of variable oceanic density structure on the sink rate of particles and to indicate the need for incorporating these considerations into numerical models. A short discussion is presented on (1) the need to make field measurements on the magnitude of both turbulence and shear in the water column and (2) the need to incorporate shear and turbulence-dependent calculations for the sink rates of particles into those numerical models which may be used to predict the particulate and effluent dispersion rates at DWD 106.
  • Technical Report
    The design and construction of a towed multi-port water sampling probe for 100 meter depths
    (Woods Hole Oceanographic Institution, 1980-05) Winget, Clifford L. ; Orr, Marshall H.
    The experimental towed multi-port water sampler was designed to provide a shipboard science party with the capability of obtaining continuous water samples from the surface to a 100 meter depth. The device will simultaneously provide six samples spaced one meter apart in a vertical plane, while being towed by a surface support vessel at a forward speed of between two to three knots. The device consists of a bottom fish containing six electric motors, each driving an individual pump. The six water samples are pumped to the surface using separate runs of TFE Teflon tubing. The tube is mounted in a pliant fairing that also houses the lifting cable, power leads, and instrumentation bundle. A drum winch is used to store a total of 150 meters of faired cable, and is capable of raising or lowering the fish while under way. The sampler will provide a discharge flow rate of 5.6 liters per minute from each sample tube, while pumping through 150 meters of 12.7 rnrn bore tubing, against a 4.5 meter head. A depth sensor transducer within the fish provides a top-side readout of the actual operating depth of the fish, while a remote reading temperature sensor provides a continuous display of the water temperature.
  • Article
    South China Sea internal tide/internal waves-impact on the temporal variability of horizontal array gain at 276 Hz
    (IEEE, 2004-10) Orr, Marshall H. ; Pasewark, Bruce H. ; Wolf, Stephen N. ; Lynch, James F. ; Schroeder, Theodore ; Chiu, Ching-Sang
    The temporal variability of the spatial coherence of an acoustic signal received on a bottomed horizontal array has been calculated for 276-Hz narrow-band signals. A conventional plane wave beamformer was applied to the received signals. The temporal variability of the array's omnipower, beam power, and array gain are related to variability in the sound-speed field. The spectral characteristics of array omnipower are nonstationary and changed as the spectral characteristics of the temperature field varied. The array omnipower and beam-power variability tracked each other in time and varied by as much as 15 dB over time intervals as short as 7 min. Array gain varied up to 5 dB and usually tracked the omnipower variability. A contiguous 24-h section of data is discussed in detail. This data section is from a time period during which the high-frequency fluid dynamic perturbation of the sound-speed field was of smaller amplitude than other sections of the 16-d data set. Consequently, this section of data sets an upper bound for the realizable array gain. The temporal variability of array gain and spatial coherence at times appears to be correlated with environmental perturbation of the sound-speed field, but are also correlated with changes in the signal-to-noise ratio. The data was acquired during the Office of Naval Research's South China Sea Asian Seas International Acoustics Experiment. The 465-m 32-channel horizontal array was placed on the bottom in 120 m of water at the South China Sea shelf break. The acoustic source was moored in 114 m of water /spl sim/19 km from the receiving array.
  • Technical Report
    Remote acoustic monitoring of natural suspensate distributions, active suspensate resuspension, and slope/shelf water intrusions
    (Woods Hole Oceanographic Institution, 1978-10) Orr, Marshall H. ; Hess, Frederick R.
    Acoustic data, transmissometer data, and calculations are presented which indicate that high-frequency acoustic backscattering systems can become a valuable tool in the remote monitoring of suspended particle distributions and active resuspension areas. Data are also presented which show that acoustic backscattering systems can be used to remotely detect slope/shelf water frontal zones. Towed acoustic systems should be able to map the extent of the frontal zone and add significantly to the understanding of frontal zone processes.
  • Technical Report
    A towed, multi-frequency H.F. sonar system for scattering and ocean dynamics studies
    (Woods Hole Oceanographic Institution, 1979-10) Hess, Frederick R. ; Orr, Marshall H.
    The system described provides wide operational flexibility at any operating frequency from 5 kHz to over 800 kHz (except for a small band around 455 kHz) limited mainly by the availability of transducers. Variable pulse width, variable receiver bandwidth, low receiver noise, various time variable gain functions and wide system dynamic range characterized the system. Built-in time-sharing controls maximize flexibility of graphics display on either dry-paper or fibre-optic CRT recorders.
  • Technical Report
    Remote acoustic sensing of oceanic fluid and biological processes
    (Woods Hole Oceanographic Institution, 1980-06) Orr, Marshall H.
    High frequency acoustic backscattering systems are being used in monostatic modes to evaluate the use of acoustic techniques to detect and study a variety of fluid processes in the oceanic environment. A short outline of those research programs actively evaluating and using acoustic techniques is presented, followed by a detailed review of this investigator's program. This program uses a multifrequency high frequency acoustic system to study a variety of processes including turbulent mixing, air-sea interactions, internal waves, interleaving water masses, natural particulate dispersion and distribution, the dispersion of particulates associated with deep ocean disposal of industrial chemical waste, and biological response to a variety of stimulae including fluid motion, predators, and oceanographic instrumentation. Graphic acoustic data records of several of the above phenomena are described.