Irish James D.

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Integrated seawater sampler and data acquisition system prototype : final report

(Woods Hole Oceanographic Institution, 1993-04) Berteaux, Henri O. ; Eck, Calvert F. ; Irish, James D. ; Jenkins, William J. ; Kery, Sean M. ; Albro, Carl S. ; McDowell, S.

This report documents the work performed by the Woods Hole Oceanographic Institution (WHOI) and the Battelle Memorial Institute from August 1988 to December 1992 in the NSF sponsored development of an Integrated Seawater Sampler and Data Acquisition Prototype. After a 6-month initial design study, a prototype underwater profiing unit was designed and constructed, containing the water acquisition subsystem, CTD and altimeter, control circuitry and batteries. A standard WHOI CTD was adapted for use in the underwater unit and was interfaced to the underwater controller which had a telemetry module connecting ít with a deck control unit. This enabled CTD data to be logged in normal fashion on shipboard while additional commands and diagnostics were sent over the telemetry link to command the underwater unit's water sampling process and receive diagnostic information on system performance. The water sampling subsystem consisted of 36 trays, each containing a plastic sample bag, the pump and control circuitry. The sample bags, initially sealed in a chemically clean environment, were opened by pumping the water out of the tray, thus forcing water into the bag by ambient pressure. The command system could select any bag, and control the water sampling procss from the surface with diagnostic information on system altitude, depth, orientation and cable tension displayed in real time for operator information. At sea tests confirmed the operation of the electrical and control system. Problems were encountered with the bags and seals which were partially solved by further post cruise efforts. However, the bag closing mechanism requires further development, and numerous small system improvements identified during the cruises need to be implemented to produce an operational water sampler. Finally, initial design tor a water sampler handling and storage unit and water extraction system were developed but not implemented. The detailed discussion of the prototype water sampler design, testing and evaluation, and new bag testing result are presented.
Preliminary acoustic and oceanographic observations from the ASIAEX 2001 South China Sea Experiment

(Woods Hole Oceanographic Institution, 2001-09) Newhall, Arthur E. ; Costello, Lawrence ; Duda, Timothy F. ; Dunn, James M. ; Gawarkiewicz, Glen G. ; Irish, James D. ; Kemp, John N. ; McPhee, Neil M. ; Liberatore, Stephen P. ; Lynch, James F. ; Ostrom, William M. ; Schroeder, Ted ; Trask, Richard P. ; von der Heydt, Keith

The Asian Seas International Experiment (ASIAEX) was a very successful scientific collaboration between the United States of America (USA), the People’s Republic of China (PRC), Taiwan (ROC), the Republic of Korea (ROK), Japan, Russia, and Singapore. Preliminary field experiments associated with ASIAEX began in spring of 2000. The main experiments were performed in April-August, 2001. The scientific plan called for two major acoustics experiments, the first a bottom interaction experiment in the East China Sea (ECS) and the second a volume interaction experiment in the South China Sea (SCS). In addition to the acoustics efforts, there were also extremely strong physical oceanography and geology and geophysics components to the experiments. This report will concentrate on describing the moored component of the South China Sea portion of ASIAEX 2001 performed from the Taiwan Fisheries research vessel FR1 (Fisheries Researcher 1). Information on the environmental moorings deployed from the Taiwanese oceanographic research vessel OR1 (Oceanographic Researcher 1) will also be listed here for completeness, so that the reader can pursue later analyses of the data. This report does not pursue any data analyses per se.
Winter 1993 observations of oceanography and sediment transport at the LEO-15 site

(Woods Hole Oceanographic Institution, 1995-12) Irish, James D. ; Lynch, James F. ; Newhall, Arthur E. ; Witzell, Nick ; Traykovski, Peter A. ; Glenn, Scott M.

The NOAA National Underseas Research Program at Rutgers University is establishing a Long-term Ecosystem Observatory off New Jersey in 15 meters of water. As part of a bottom boundary layer study at this site, WHOI deployed a bottom instrument frame during the winter of 1993-94. The bottom instrument carried a current meter, a vertical array of optical back scattering sensors, temperature, pressure and conductivity sensors and an Acoustical Backscattering Sensor. The deployment was partially successful as the acoustic system failed. The other instrumentation worked well for 3 weeks returning data on winter conditions at the site. The extreme winter waves ended the experiment by tipping the instrument over on its side. The optical instrumentation was calibrated with sediment from the site, and the results from the experiment presented.
New broadband methods for resonance classification and high-resolution imagery of fish with swimbladders using a modified commercial broadband echosounder

(Oxford University Press, 2010-01-05) Stanton, Timothy K. ; Chu, Dezhang ; Jech, J. Michael ; Irish, James D.

A commercial acoustic system, originally designed for seafloor applications, has been adapted for studying fish with swimbladders. The towed system contains broadband acoustic channels collectively spanning the frequency range 1.7–100 kHz, with some gaps. Using a pulse-compression technique, the range resolution of the echoes is ~20 and 3 cm in the lower and upper ranges of the frequencies, respectively, allowing high-resolution imaging of patches and resolving fish near the seafloor. Measuring the swimbladder resonance at the lower frequencies eliminates major ambiguities normally associated with the interpretation of fish echo data: (i) the resonance frequency can be used to estimate the volume of the swimbladder (inferring the size of fish), and (ii) signals at the lower frequencies do not depend strongly on the orientation of the fish. At-sea studies of Atlantic herring demonstrate the potential for routine measurements of fish size and density, with significant improvements in accuracy over traditional high-frequency narrowband echosounders. The system also detected patches of scatterers, presumably zooplankton, at the higher frequencies. New techniques for quantitative use of broadband systems are presented, including broadband calibration and relating target strength and volume-scattering strength to quantities associated with broadband signal processing.
Tides of Massachusetts and Cape Cod Bays

(Woods Hole Oceanographic Institution, 1992-09) Irish, James D. ; Signell, Richard P.

The Massachusetts Bays Program made bottom pressure and water velocity observations in Massachusetts and Cape Cod Bays during 1990 and 1991. In the Bays, the sea surface elevation appeared to rise and fall in phase with equal amplitudes at each diurnal or semidiurnal tidal frequency. There is some amplification in Boston and Provincetown harbors. The semidiurnal tides (particularly the M2 constituent) dominate. Massachusetts and Cape Cod Bays are part of the Gulf of Maine/Bay of Fundy system which is resonant near the semidiurnal frequency. This resonance amplifies the importance of the semidiurnal tides so that diurnal and higher harmonic tides become negligible. The sea level tides force currents which move with the same frequencies, but whose amplitudes are affected by the bathymetry. The strongest currents exist in the channel between Race Point and Stellwagen Bank where tidal currents exceed 1 knot. Analysis of current records for their tidal signal is complicated by internal tides which contaminate the records. These internal waves at tidal frequency exist on the stratification in the water column, and disappear during winter well-mixed times. At other times they must be considered as a signifcant source of energy for mixing and resuspension of sediments.
The 1995 Georges Bank Stratification Study and moored array measurements

(Woods Hole Oceanographic Institution, 2001-08) Alessi, Carol A. ; Beardsley, Robert C. ; Caruso, Michael J. ; Churchill, James H. ; Irish, James D. ; Lentz, Steven J. ; Limeburner, Richard ; Werner, R. ; Weller, Robert A. ; Williams, Albert J. ; Williams, William J. ; Manning, James P. ; Smith, P.

The 1995 Geoges Bank Stratification Study (GBSS) was the first intensive process study conducted as part of the U.S. GLOBEC Northwest Atlantic/Georges Bank field program. The GBSS was designed to investigate the physical processes which control the seasonal development of stratification along the southern flank of Georges Bank during spring and summer. Past work suggested that during this period, larval cod and haddock tended to aggregate to the thermocline on the southern flank where higher concentrations of their copepod prey were found. A moored array was deployed as part of GBSS to observe the onset and evolution of sesonal stratification over the southern flank with sufficient vertical and horizontal resolution that key physical processes could be identified and quantified. Moored current, temperature, and conductivity (salinity) measurements were made at three sites along the southern flank, one on the crest, and one on the northeast peak of the bank. Moored surface meteorological measurements were also made at one southern flank site to determine the surface wind stress and heat and moisture fluxes. The oceanographic and meteorological data collected with the GBSS array during January-August 1995 are presented in this report. Meteorological data collected on National Data Buoy Center environmental buoys 44011 (Georges Bank), 44008 (Nantucket Shoals), and 44005 (Gulf of Maine) are included in this report for completeness and comparison with the GBSS southern flank meteorological measurements.
Nantucket shoals flux experiment (NSFE79) : part 2, moored array data report

(Woods Hole Oceanographic Institution, 1983-11) Beardsley, Robert C. ; Alessi, Carol A. ; Vermersch, John A. ; Brown, W. Steven ; Pettigrew, Neal R. ; Irish, James D. ; Ramp, Steven R. ; Schlitz, Ronald J. ; Butman, Bradford

The Nantucket Shoals Flux Experiment (NSFE79) was conducted across the continental shelf and upper slope south of Nantucket from March, 1979 to April , 1980 to measure the flow of shelf water from the Georges Bank/Gulf of Maine region into the Middle Atlantic Bight. Conceived as a cooperative field experiment involving the Northeast Fisheries Center (NMFS), U.S. Geological Survey (Woods Hole), University of New Hampshire, and the Woods Hole Oceanographic Institution, the experiment contained two principal components, a moored array of current meter and bottom instrumentation deployed at six locations across the shelf and upper slope spanning a depth range from 46 m to 810 m, and a series of 27 hydrographic surveys made along or near the moored array line during the experiment. A basic description of the NSFE79 hydrographic data has been given in Part 1 by Wright (1983). A description of the moored array components and the basic moored array data sets is presented here in Part 2.
Acoustic and oceanographic observations and configuration information for the WHOI moorings from the SW06 experiment

(Woods Hole Oceanographic Institution, 2007-05) Newhall, Arthur E. ; Duda, Timothy F. ; von der Heydt, Keith ; Irish, James D. ; Kemp, John N. ; Lerner, Steven A. ; Liberatore, Stephen P. ; Lin, Ying-Tsong ; Lynch, James F. ; Maffei, Andrew R. ; Morozov, Andrey K. ; Shmelev, Alexey A. ; Sellers, Cynthia J. ; Witzell, Warren E.

This document describes data, sensors, and other useful information pertaining to the moorings that were deployed from the R/V Knorr from July 24th to August 4th, 2006 in support of the SW06 experiment. The SW06 experiment was a large, multi-disciplinary effort performed 100 miles east of the New Jersey coast. A total of 62 acoustic and oceanographic moorings were deployed and recovered. The moorings were deployed in a “T” geometry to create an along-shelf path along the 80 meter isobath and an across-shelf path starting at 600 meters depth and going shoreward to a depth of 60 meters. A cluster of moorings was placed at the intersection of the two paths to create a dense sensor-populated area to measure a 3-dimensional physical oceanography. Environmental moorings were deployed along both along-shelf and across-shelf paths to measure the physical oceanography along those paths. Moorings with acoustic sources were placed at the outer ends of the “T” to propagate various signals along these paths. Five single hydrophone receivers were positioned on the across shelf path and a vertical and horizontal hydrophone array was positioned at the intersection of the “T” to get receptions from all the acoustics assets that were used during SW06.
Deployment of a bottom monitor at a 30 meters deep site in the New York Bight Apex during the summer of 1993

(Woods Hole Oceanographic Institution, 1993-09) Irish, James D.

A bottom instrument was deployed on May 5,1993, recovered and redeployed on June 22, 1993 and finally recovered on July 28, 1993 at a 30 meter site in the New York Bight Apex. The instrument measured currents, suspended sediment concentrations, pressure, temperature and conductivity. The data storage was filled in only seven days on the first deployment as in 18 days in the second. The averaging sampling process worked well, producing hourly (first deployment) and half hourly (second deployment) values of all sensors and instrument internal diagnostics to obtain background environmental information. The burst sampling scheme sampled once a day for waves, and identified 6 and 10 second waves present. The event sampling scheme was tested for the first time. During deployment one, high frequency pressure signals were allowed to trigger events, and bad cabling caused excessive events to be recorded, filling the memory prematurely. For deployment two, only the optical sediment sensors were allowed to trigger events, and 146 events were recorded. Many of the events were only seen in one or the other optical sensor and probably associated with fish or floating debris. Other events had unique signatures, one type possibly due to passing ships.
Mine burial experiments at the Martha’s Vineyard Coastal Observatory

(IEEE, 2007-01) Traykovski, Peter A. ; Richardson, Michael D. ; Mayer, Larry A. ; Irish, James D.

Several experiments to measure postimpact burial of seafloor mines by scour and fill have been conducted near the Woods Hole Oceanographic Institution's Martha's Vineyard Coastal Observatory (MVCO, Edgartown, MA). The sedimentary environment at MVCO consists of a series of rippled scour depressions (RSDs), which are large scale bedforms with alternating areas of coarse and fine sand. This allows simultaneous mine burial experiments in both coarse and fine sand under almost identical hydrodynamic forcing conditions. Two preliminary sets of mine scour burial experiments were conducted during winters 2001?2002 in fine sand and 2002?2003 in coarse sand with a single optically instrumented mine in the field of view of a rotary sidescan sonar. From October 2003 to April of 2004, ten instrumented mines were deployed along with several sonar systems to image mine behavior and to characterize bedform and oceanographic processes. In fine sand, the sonar imagery of the mines revealed that large scour pits form around the mines during energetic wave events. Mines fell into their own scour pits, aligned with the dominant wave crests and became level with the ambient seafloor after several energetic wave events. In quiescent periods, after the energetic wave events, the scour pits episodically infilled with mud. After several scour and infilling events, the scour pits were completely filled and a layer of fine sand covered both the mines and the scour pits, leaving no visible evidence of the mines. In the coarse sand, mines were observed to bury until the exposed height above the ripple crests was approximately the same as the large wave orbital ripple height (wavelengths of 50?125 cm and heights of 10?20 cm). A hypothesis for the physical mechanism responsible for this partial burial in the presence of large bedforms is that the mines bury until they present roughly the same hydrodynamic roughness as the orbital-scale bedforms present in coarse sand.
Barotropic tide in the northeast South China Sea

(IEEE, 2004-10) Beardsley, Robert C. ; Duda, Timothy F. ; Lynch, James F. ; Irish, James D. ; Ramp, Steven R. ; Chiu, Ching-Sang ; Tang, Tswen Yung ; Yang, Yiing-Jang ; Fang, Guohong

A moored array deployed across the shelf break in the northeast South China Sea during April-May 2001 collected sufficient current and pressure data to allow estimation of the barotropic tidal currents and energy fluxes at five sites ranging in depth from 350 to 71 m. The tidal currents in this area were mixed, with the diurnal O1 and K1 currents dominant over the upper slope and the semidiurnal M2 current dominant over the shelf. The semidiurnal S2 current also increased onshelf (northward), but was always weaker than O1 and K1. The tidal currents were elliptical at all sites, with clockwise turning with time. The O1 and K1 transports decreased monotonically northward by a factor of 2 onto the shelf, with energy fluxes directed roughly westward over the slope and eastward over the shelf. The M2 and S2 current ellipses turned clockwise and increased in amplitude northward onto the shelf. The M2 and S2 transport ellipses also exhibited clockwise veering but little change in amplitude, suggesting roughly nondivergent flow in the direction of major axis orientation. The M2 energy flux was generally aligned with the transport major axis with little phase lag between high water and maximum transport. These barotropic energy fluxes are compared with the locally generated diurnal internal tide and high-frequency internal solitary-type waves generated by the M2 flow through the Luzon Strait.
The determination of the elastic modulus of rubber mooring tethers and their use in coastal moorings

(Woods Hole Oceanographic Institution, 2005-12) Irish, James D. ; Paul, Walter ; Wyman, David M.

Compliance must be supplied to any surface mooring to allow the buoy to move with the waves and currents, and remain moored in position. This can be supplied with a traditional chain catenary or newer compliant elastic tether or stretch hose technologies. Some applications of each of these three techniques are shown, with the emphasis placed on the use of compliant elastic tethers. For modeling and designing these moorings, the elastic modulus of the tether material must be known. Therefore, a new and used piece of elastic material was terminated, tested for the stretch-strain relationship under set conditions, and the elastic modulus calculated. For these tests, the elastic tether was stretched out to a mean elongation between 100 and 250%, then cycled about that stretch by ±25 and ±50% to duplicate a moored application. The resultant elastic modulus is presented to aid in mooring design. At low elongations, the elastic modulus is constant at about 125 PSI, but as the mean elongation increases the modulus increases, and as the cycle tension increase the modulus also increases, reaching a maximum of 900 PSI at 275% stretch.
Long-term moored array measurements of currents and hydrography over Georges Bank : 1994–1999

( 2009-06-24) Brink, Kenneth H. ; Beardsley, Robert C. ; Limeburner, Richard ; Irish, James D. ; Caruso, Michael J.

In conjunction with the GLOBEC (Global Ocean Ecosystems Dynamics) program, measurements of moored currents, temperature and salinity were made during 1994-1999 at locations in 76 m of water along the Southern Flank of Georges Bank and at the Northeastern Peak. The measurements concentrate on the biologically crucial winter and spring periods, and coverage during the fall is usually poorer. Current time series were completely dominated by the semidiurnal M2 tidal component, while other tidal species (including the diurnal K1 component) were also important. There was a substantial wind-driven component of the flow, which was linked, especially during the summer, to regional–scale response patterns. The current response at the Northeast Peak was especially strong in the 3-4 day period band, and this response is shown to be related to an amplifying topographic wave propagating eastward along the northern flank. Monthly mean flows on the southern flank are southwestward throughout the year, but strongest in the summertime. The observed tendency for summertime maximum along-bank flow to occur at depth is rationalized in terms of density gradients associated with a near-surface freshwater tongue wrapping around the Bank. Temperature and salinity time series demonstrate the presence, altogether about 25% of the time, of a number of intruding water masses. These intrusions could last anywhere from a couple days up to about a month. The sources of these intrusions can be broadly classified as the Scotian Shelf (especially during the winter), the Western Gulf of Maine (especially during the summer), and the deeper ocean south of Georges Bank (throughout the year). On longer time scales, the temperature variability is dominated by seasonal temperature changes. During the spring and summer, these changes are balanced by local heating or cooling, but wintertime cooling involves advective lateral transports as well. Salinity variations have weak, if any, seasonal variability, but are dominated by interannual changes that are related to regional- or basin-scale changes. All considered, Georges Bank temperature and salinity characteristics are found to be highly dependent on the surrounding waters, but many questions remain, especially in terms of whether intrusive events leave a sustained impact on Bank waters.
CODE-1 : moored array and large-scale data report

(Woods Hole Oceanographic Institution, 1983-08) Beardsley, Robert C. ; Mills, Carol A. ; Rosenfeld, Leslie K. ; Bratkovich, Alan W. ; Erdman, M. Rustin ; Winant, Clinton D. ; Allen, John S. ; Halliwell, George R. ; Brown, Wendell S. ; Irish, James D.

The Coastal Ocean Dynamics Experiment (CODE) was undertaken to identify and study the important dynamical processes which govern the wind-driven motion of coastal water over the continental shelf. The initial effort in this multi-year, multi-institutional research program was to obtain high-quality data sets of all the relevant physical variables needed to construct accurate kinematic and dynamic descriptions of the response of shelf water to strong wind forcing in the 2 to 10 day band. A series of two small-scale, densely-instrumented field experiments of approximately four months duration (called CODE-1 and CODE-2) were designed to explore and to determine the kinematics and momentum and heat balances of the local wind-driven flow over a region of the northern California shelf which is characterized by both relatively simple bottom topography and large wind stress events in both winter and summer. A more lightly instrumented, long-term, large-scale component was designed to help separate the local wind-driven response in the region of the small-scale experiments from motions generated either offshore by the California Current system or in some distant region along the coast, and also to help determine the seasonal cycles of the atmospheric forcing, water structure, and coastal currents over the northern California shelf. The first small-scale experiment (CODE-1) was conducted between April and August, 1981 as a pilot study in which primary emphasis was placed on characterizing the wind-driven "signal" and the "noise" from which this signal must be extracted. In particular, CODE-1 was designed to identify the key features of the circulation and its variability over the northern California shelf and to determine the important time and length scales of the wind-driven response. This report presents a basic description of the moored array data and some other Eulerian data collected during CODE-1. A brief description of the CODE-1 field program is presented first, followed by a description of the common data analysis procedures used to produce the various data sets presented here. Then basic descriptions of the following data sets are presented: (a) the coastal and moored meteorological measurements, (b) the moored current measurements, (c) the moored temperature and conductivity observations, (d) the bottom pressure measurements, and (e) the wind and adjusted coastal sea level observations obtained as part of the CODE-1 large-scale component.
U.S. GLOBEC Georges Bank long-term moored program : part 1 - mooring configuration

(Woods Hole Oceanographic Institution, 2005-12) Irish, James D. ; Kerry, S. ; Fucile, Paul D. ; Beardsley, Robert C. ; Lord, Jeffrey ; Brink, Kenneth H.

As part of the U.S. GLOBEC Northwest Atlantic/Georges Bank program, moorings were deployed on Georges Bank as part of the broad-scale survey component to help measure the temporal variability of both physical and biological characteristics on the Bank. The array consisted of a primary mooring site on the Southern Flank which was maintained for the full 5-year duration of the field program, plus secondary moorings, with fewer sensors and of shorter duration, in the well-mixed water on the Crest and in the cod/haddock spawning region on the Northeast Peak. Temperature and conductivity (salinity) were measured at 5-m intervals, ADCP velocity profiles were obtained with 1-m vertical resolution, and bio-optical packages (measuring fluorescence, optical transmission and photosynthetically active radiation) were deployed at 10-m and 40-m depths. Bottom pressure was measured at the Southern Flank site. The buoy design, sensors and mooring configuration is presented and discussed below, and the data obtained is presented and discussed in an accompanying reports “U.S. GLOBEC Georges Bank Long-Term Moored Program: Part 2 – Yearly Data Summary and Report,” and “U.S. GLOBEC Georges Bank Long-Term Moored Program: Part 3 – Data Summary.”
A preliminary description of the CODE-1 field program

(Woods Hole Oceanographic Institution, 1982-12) Allen, John S. ; Beardsley, Robert C. ; Brown, Wayne S. ; Cacchione, David A. ; Davis, Russ E. ; Drake, David E. ; Friehe, Carl A. ; Grant, William D. ; Huyer, Adriana ; Irish, James D. ; Janopaul, M. M. ; Williams, Albert J. ; Winant, Clinton D.

A Coastal Ocean Dynamics Experiment (CODE) has been undertaken to identify and study the important dynamical processes which govern the wind-driven motion of coastal water over the continental shelf. The initial effort in this four-year research program is to obtain high-quality data sets of all the relevant physical variables needed to construct accurate kinematic and dynamic descriptions of the response of shelf water to strong wind forcing in the 2 to 10-day band. A series of two small-scale, densely-instrumented field experiments of four-month duration (CODE-1 and CODE-2) is designed to explore and to determine the kinematics and momentum and heat balances of the local wind-driven flow over a region of the northern California shelf which is characterized by both relatively simple bottom topography and large wind stress events in both winter and summer. A more lightly-instrumented, long-term, large-scale component has been designed to help separate the local wind-driven response in the region of the small-scale experiments from motions generated either offshore by the California Current system or in some distant region along the coast, and also to help determine the seasonal cycles of the atmospheric forcing, water structure, and coastal currents over the northern California shelf. This report presents an overview of the CODE program and a preliminary description of the observational programs conducted during CODE-1. The various logical components of CODE are identified and described, and their relationship to the entire effort is discussed. The report itself represents a minor revision of the original cover proposal submitted to NSF in late 1979 by the principal investigators and is not a comprehensive guide nor does it contain any descriptions of the initial results from CODE-1. Scientific and engineering results will be presented elsewhere in individual technical and scientific reports. CODE has been jointly conceived by the following principal investigators (who collectively make up the CODE group): J. Allen , R. Beardsley, W. Brown, 0. Cacchione, R. Davis, D. Drake , C. Friehe, W. Grant, A. Huyer, J. Irish, M. Janopaul, A. Williams and C. Winant.
Instrumentation for open ocean aquaculture monitoring

(Woods Hole Oceanographic Institution, 2001-10) Irish, James D. ; Carroll, Megan ; Singer, Robin C. ; Newhall, Arthur E. ; Paul, Walter ; Johnson, Craig ; Witzell, Nick ; Rice, Glen ; Fredriksson, David W.

The Woods Hole Oceanographic Institution is assisting the University of New Hampshire by instrumenting a fish cage and mooring as part of their Open Ocean Aquaculture demonstration program in the Gulf of Maine. To understand these systems, the wave and current forcing and the response of the mooring and fish cage needs to be measured. A UNH mooring with an ADCP measured the current forcing. Tension in the mooring lines was measured by load cells deployed with the mooring during servicing in August 2000. Load cells were placed in each anchor line, and, in the NE corner, also in the two grid lines and the riser line to the fish cage. Low power recording systems were deployed on the load cell mounting bars by divers on 22 October 2000, recorded good data through January 2001, when they were turned around and redeployed. Three single load cell recorders were recovered in July 2001 and recorded though 23 June when their data storage filled. The four load cell system was recovered in March after a large winter storm, and had failed in early March. The wave forcing was measured with a wave rider buoy with a 3-axis accelerometer measuring its motion. The acceleration was integrated twice to obtain wave displacement. The system mooring contained a compliant elastic. The wave rider was deployed on 4 January 2001 and recovered on 17 March 2001 after a major Northeast storm. It recorded data throughout its deployment. The motion of the moored fish cage was measured by a motion package constructed around a 6-axis Motion-Pak and a PC-104 data system. The motion package was deployed on the fish cage from Jan into March 2001 and recorded motions thoughout without difficuly. It observed a major storm in early March where the counter weight was lost from the fish cage, and its increase in motion thereafter.
Internal tide and nonlinear internal wave behavior at the continental slope in the northern south China Sea

(IEEE, 2004-10) Duda, Timothy F. ; Lynch, James F. ; Irish, James D. ; Beardsley, Robert C. ; Ramp, Steven R. ; Chiu, Ching-Sang ; Tang, Tswen Yung ; Yang, Yiing-Jang

A field program to measure acoustic propagation characteristics and physical oceanography was undertaken in April and May 2001 in the northern South China Sea. Fluctuating ocean properties were measured with 21 moorings in water of 350- to 71-m depth near the continental slope. The sea floor at the site is gradually sloped at depths less than 90 m, but the deeper area is steppy, having gradual slopes over large areas that are near critical for diurnal internal waves and steep steps between those areas that account for much of the depth change. Large-amplitude nonlinear internal gravity waves incident on the site from the east were observed to change amplitude, horizontal length scale, and energy when shoaling. Beginning as relatively narrow solitary waves of depression, these waves continued onto the shelf much broadened in horizontal scale, where they were trailed by numerous waves of elevation (alternatively described as oscillations) that first appeared in the continental slope region. Internal gravity waves of both diurnal and semidiurnal tidal frequencies (internal tides) were also observed to propagate into shallow water from deeper water, with the diurnal waves dominating. The internal tides were at times sufficiently nonlinear to break down into bores and groups of high-frequency nonlinear internal waves.
Deployment of the northern fish cage and mooring, University of New Hampshire — Open Ocean Aquaculture Program summer 2000

(Woods Hole Oceanographic Institution, 2000-09) Irish, James D. ; Paul, Walter ; Ostrom, William M. ; Chambers, Michael ; Fredriksson, David W. ; Stommel, Matt

The University of New Hampshire - Open Ocean Aquaculture (UNH-OOA) program has worked for the past few years on developing the technology to deploy and maintain fish cages in open, exposed northern waters. In June 1999, two Sea Station octagonal net cages by Ocean Spar Technologies were deployed with their UNH designed and constructed moorings. In June 2000 the Northern Cage and its mooring were retrieved, examined and repaired , and readied for redeployment. This was a complex operation, initiated by a team of UNH ocean engineers lead by Dr. Barbaros Celikkol. This year's effort was expanded with the addition of a Program Manager (Michael Chambers), the Fishing Vessel Nobska, and researchers from the Woods Hole Oceanographic Institution (WHOI). During the week of 21 to 25 August 2000, the cage and mooring were assembled and deployed at the UNH-OOA site seven miles offshore the New Hampshire coast, south of the Isle of Shoals. This collaborative effort involved members of the UNH Mechanical Engineering Dept., UNH divers, members of the WHOI Applied Ocean Physics & Engineering Dept. and the Captain and crew of the FV Nobska. Ship support for the deployment was provided by the R/V Gulf Challenger and Galen J. (UNH) and the FV Nobska (a 100 foot fishing vessel based at Woods Hole, MA). The work was favored by light wind and sea conditions. The endeavor resulted in the successful placement of the North Cage and its complex mooring system with load cells and environmental sensors. Unexpected and unexplained tangling of the mooring system, in particular near its grid corner points, was encountered and corrected.
LOCOMOOR : a LOw-COst MOORing for the measurement of internal solitary waves

( 2000-05-09) Lord, Jeffrey ; Irish, James D. ; Duda, Timothy F. ; Kemp, John N.

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 temperature moorings (LOCOMOOR) has been developed. The basic concept is to provide spatial coverage as opposed to dense vertical resolution in temperature. Three temperature sensors on each mooring will adequately measure the time of passage of the internal solitary waves. A horizontal array of 20 of these moorings deployed for about three weeks will allow the internal solitary wave front geometry (curvature) and velocity to be measured as they propagate through the experiment region. The arrival time of each pulse within the packet of internal waves will be easily resolved, but the wave amplitude less exactly estimated. However, the amplitude will be very well measured by the velocity and density observations on the more heavily instrumented environmental moorings associated with the acoustic experiment.

Irish James D.

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