GoMOOS Ocean Observation Technology: Present and Future Neal R Pettigrew GoMOOS Chief Scientist Phys

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GoMOOS Ocean Observation TechnologyPresent and
FutureNeal R Pettigrew GoMOOS Chief
ScientistPhysical Oceanography GroupUniversity
of Maine
N
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Outline

• The Gulf of Maine Ocean Observing System (GoMOOS)
  Multiple purposes of Ocean Observing systems.
• Technology in GoMOOS. What does it do? How is it
  done? How will it expand and improve in the near
  future?
• Educational Challenges What knowledge and skills
  are needed for those who will operate the OOS?
  What knowledge and skills are needed by those who
  will use GoMOOS in the classroom?

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Multiple Purposes of the Observing System

• Scientific, Practical, and Educational Missions
• Advance scientific understanding of how the Gulf
  of Maine operates as a physical and ecological
  system. Reveal the seasonal, interannual, and
  decadal variability of the oceanography of the
  Gulf of Maine and its major bays and estuaries,
  and the impact of this variability on fisheries
  and environmental quality.
• Provide hourly real-time data to National Weather
  service (forecasting, winds and waves) USCG
  (search and rescue, oil spill response), shipping
  industry, fishing industry, and recreational
  boaters. Provide archived data, model output,
  data interpretations to environmental regulators
  and planners to facilitate the formulation of
  marine public policy.
• Provide a window on the Gulf to educators and
  students in order to stimulate interest in the
  marine environment and to facilitate training for
  future scientists, engineers, technicians,
  managers and ocean educators.

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Technical Program
Real-time monitoring of meteorological and
Oceanographic Conditions Weather --
surface winds, air temperature, visibility (fog),
incident light, barometric pressure Oceanic
conditions -- currents, waves, temperature,
salinity Environmental quality dissolved
oxygen, inorganic nutrients Ocean optics
Chlorophyll fluorescence , water-column light
field, ocean color, multi-wavelength attenuation,
water clarity Modeling circulation
waves Web delivery of data and data
products Hourly data delivery www.GoMOOS.org
gyre_at_umeoce.maine.edu coming soon
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GoMOOS Shelf Buoy

• Unsinkable combination of hard and soft
  flotation.
• Dual telemetry system cellular/irridium phone
  and GOES satellite links.
• Stable enough to support technician topsides and
  build-up of sea ice on superstructure.
• Artificially intelligent -position, leak, and
  power alarms.

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Built in wave accelerometer
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Buoy Electronic in the well
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Buoy Electronics
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GoMOOS Shelf BuoyCurrent measurements are made
using acoustic Doppler technology. Surface
current meter 2.5 megahertz makes near-surface in
situ measurements.Subsurface current
measurements made using a 300 kHz acoustic
Doppler profiler. Range 150 m, 4 m vertical
resolution of the profile.
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Current Measurement and the Piezoelectric effect

• A voltage difference is generated between
  surfaces of solid dielectric materials (poor
  conductors, efficient supporters of electric
  fields) when a mechanical stress or compression
  is applied. Conversely, when a voltage is
  applied, a mechanical distortion occurs. Most
  commonly used piezoelectric materials are
  ceramics.
• If an oscillating voltage is applied to the
  surfaces of a ceramic cylinder, it oscillates at
  the same frequency as the voltage fluctuations
  applied.and generates compression waves in air
  or liquid that we refer to as sound. Conversely,
  if a ceramic cylinder is exposed to compression
  waves it will generate fluctuating voltages in
  response... We refer to these measured
  fluctuations as data. This reciprocal
  relationship between voltage and compression is
  the basis of acoustic transducer operation.
• Ceramics, quartz are two common piezoelectric
  material. Deep sea pressure sensors are made of
  quartz crystals. Acoustic transducers are made
  of ceramics, and hydrophones.

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Remote-sensing acoustic Doppler current
measurement technology

• Sound is emitted by ceramic transducers and
  scattered by plankton embedded in the flow.
  Sound backscattered to the transducers is
  Doppler-shifted in frequency. The shift in
  frequency is proportional to the speed of the
  scatterers, and thus to the speed of the water.
• Advantages of Acoustic Doppler technology
• No moving parts
• Immune to bio-fouling
• Can avoid self-wake contamination
• Profiler can act as the equivalent of 128
  individual current meters.

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GoMOOS Currents Meters
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Near-Surface Current Measurements

• Use of Doppler Profilers for near-surface current
  measurement is problematic due to contamination
  in the near field from reverberations and
  side-lobe reflections from the sea surface.
• Aanderaa in situ Doppler current meter emits
  sound pulses that propagate horizontally from
  four transducers . Only up Doppler returns are
  used to eliminate the two channels potentially
  affected by instrument wake. Measurements are
  made between 0.5 m and 1.5 m from the instrument.
  The instrument is deployed at 2m depth so side
  lobes dont reflect from the surface and cause
  contamination until the measurement is done and
  the instrument stops listening.

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GoMOOS Shelf BuoyInductive modem
systemtelemeters subsurface data up the mooring
cable.Up to 100 subsurface sensors addressable
by the inductive modem system.Modular
DesignServiceable at Sea
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Buoy Architecture The inductive modem

• Inductive modem technology based on transformer
  design.
• The mooring cable in used as the secondary
  winding.
• Voltage fluctuations (data) are induced in the
  mooring cable itself.

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How the system works

• Sensor mounted on Cable with primary winding
  attached.
• Induces Voltage fluctuations (data) in cable
  (secondary winding)
• Cable in turn induces voltage fluctuations in the
  inductive cable coupler, which is electrically
  connected to surface inductive modem in the buoy.
  

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Inductive cable coupler

• ICC attached on mooring cable above shallowest
  instrument.
• Electrical Cable attached to surface inductive
  modem inside the buoy

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Induction Modem Instruments
Temperature/Conductivyy sensor with built in IM
(right)
Diagram of Temperature/ Conductivity/ Dissolved
Oxygen Sesnor (far right)
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External Inductive Modem
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Flexibility of the Inductive Modem Technology

• Up to 100 instruments can telemeter data up the
  mooring cable without direct electrical
  connection to the buoy! (avoids electrical trunk
  line)
• Instruments can be mounted at any depth, and
  their positions changed without requiring
  redesign or remanufacture of the cable.
• Relative positions of sensors may be switched
  with only a software change.
• Instruments can be removed or replaced by divers
  without requiring recovery of the buoy itself
  (MAJOR OPERATION).

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Buoy Deployment

• Buoy deployment and recovery are major
  operations.
• GoMOOS has built 21 buoys for 10 monitoring
  locations. Each buoy pair rotated on 6 month
  rotation schedule. The extra buoy is for
  emergency response.
• A smaller nearshore version of the GoMOOS buoy is
  being designed. The nearshore buoy will be
  deployable from Lobster Boats. Mini buoy
  designed for estuarine envronments.

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Measurement of Surface Currents using radio waves

• Surface currents, averaged over several square
  kilometers, can be measured out to a range of
  100-200 kilometers from shore using a radio wave
  system called Coastal Ocean Dynamics Applications
  Radar (CODAR). It is not a microwave radar it
  has a wavelength of 10s of meters and is in a
  frequency band between AM and FM radio.
• It is a remote sensing system, immune to cloud
  cover and fog. However its use depends upon
  presence of short surface water waves, and the
  long-range CODAR is susceptible to ionospheric
  interference.
• Requires multiple shore stations and large
  antennas.

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Pettigrew, 1996
Uses of CODAR Current Data in the GOM
Schematic of the Summer Circulation of the Gulf
of Maine

• The monitoring the surface circulation
  independent of fog and cloud cover.
• Pollutant and larval transport.
• Search and rescue.

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CODAR Operating Principals

• Radio ground wave propagates well along the
  air-sea interface, but dies out rapidly over
  land.
• Bragg scattering Radio waves propagating over
  the wavy sea surface will be scattered by sea
  surface waves. The scattering by water waves of
  precisely half the radio wavelength is directly
  back toward the radio source rather than in all
  directions. This phenomenon causes the
  scattering from one surface wave to dominate the
  returns from all other surface waves.
• The back-scattered radio signal will be Doppler
  shifted because 1) waves are moving, and 2)
  surface currents.
• Wave speed can be compensated since it is a
  function of its known wavelength in deep water.
• The remaining Doppler shift is caused by, and
  proportional to, surface currents (and noise)!

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Long Range CODAR

• New Long range systems operate in the 4 -5
  megahertz shortwave band. Between AM and FM
  bands.
• Bragg scattering occurs from waves of
  approximately 30 m wavelength.4.5 sec periods.
  These waves are nearly always present and are
  generated by light transient winds.
• Range of the systems are 100 -200 km depending on
  background radio noise and ionospheric
  interference.

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CODAR Installation (Greens Island)
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Theoretical coverage of long-range CODAR in the
Gulf of Maine

• Areas of overlapping coverage provide
  two-dimensional surface current measurements.
• CODAR-derived surface currents have been shown to
  correlate well with GoMOOS Doppler currents at
  2m.
• Long-range CODAR offers an opportunity for early
  connections of regional observing systems

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CODAR Current Vector Fields

• First panel shows vectors from the Greens Island
  and Cape Saint Mary installations.
• The second panel shows results from Nantucket,
  Block Island, Long Island, and New Jersey
  installations.

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Greens Island CODAR-Buoy M Surface Current
Comparison
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Future GoMOOS Developments

• Moored real-time nutrient sensors.
• Smaller, cheaper, more easily deployed near-shore
  buoys to monitor estuary-shelf and
  estuary-estuary coupling.
• Additional buoys farther offshore to monitor the
  inflows and outflows to the Gulf of Maine and
  conditions in the basins.
• Short range high speed wireless connections
  between ships and buoys so that buoys can be
  checked after deployment and sensors reprogrammed
  etc. without the necessity of pulling the buoy on
  deck and physically plugging into it.
• Other forms of satellite telemetry short message
  service, direct internet connection. Cheaper,
  but one way communication. Just receive data,
  cant send commands.
• Replace in situ optical, hydrographic, and DO
  sensors with vertically profiling packages.
• Coupled physical and ecological models on line
  to fill in the gaps between observations and to
  predict changes.
• Development buoy for testing and integrating
  new sensors, data systems, telemetry etc.,
  allowing the evolution of the GoMOOS system
  without jeopardizing the sustained real-time
  monitoring mission of the observing system.
• Buoy-mounted CODAR systems for expanded coverage,
  reduced error, and long-range ship tracking.

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GoMOOS/NOAA Monitoring Array

• Large unlabeled red dots indicate the locations
  of potential GoMOOS real-time data buoys for the
  interior of the Gulf. Georges Bank and the
  Scotian shelf are areas that would tie GoMOOS to
  a larger regional system.
• Small unlabeled red dots indicate potential
  locations of nearshore and harbor buoys.

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44018
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Future GoMOOS Developments

• Moored real-time nutrient sensors.
• Smaller, cheaper, more easily deployed near-shore
  buoys to monitor estuary-shelf and
  estuary-estuary coupling.
• Additional buoys farther offshore to monitor the
  inflows and outflows to the Gulf of Maine.
• Short range high speed wireless connections
  between ship and buoys so that buoys can be
  checked after deployment and sensors reprogrammed
  etc. without the necessity of pulling the buoy on
  deck and physically plugging into it.
• Other forms of telemetry short message service,
  direct internet connection. Cheaper, but one way
  communication. Just receive data.
• Replace in situ optical, hydrographic, and DO
  sensors with vertically profiling packages.
• Coupled physical and ecological models on line
  to fill in the gaps between observations and to
  predict changes.
• Development buoy for testing and integrating
  new sensors, data systems, telemetry etc.,
  allowing the evolution of the GoMOOS system
  without jeopardizing the sustained real-time
  monitoring mission of the observing system.
• Buoy-mounted CODAR systems for expanded coverage,
  reduced error, and long-range ship tracking.

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Future GoMOOS Developments

• Moored real-time nutrient sensors.
• Smaller, cheaper, more easily deployed near-shore
  buoys to monitor estuary-shelf and
  estuary-estuary coupling.
• Additional buoys farther offshore to monitor the
  inflows and outflows to the Gulf of Maine.
• Short range high speed wireless connections
  between ship and buoys so that buoys can be
  checked after deployment and sensors reprogrammed
  etc. without the necessity of pulling the buoy on
  deck and physically plugging into it.
• Other forms of telemetry short message service,
  direct internet connection. Cheaper, but one way
  communication. Just receive data.
• Replace in situ optical, hydrographic, and DO
  sensors with vertically profiling packages.
• Coupled physical and ecological models on line
  to fill in the gaps between observations and to
  predict changes.
• Development buoy for testing and integrating
  new sensors, data systems, telemetry etc.,
  allowing the evolution of the GoMOOS system
  without jeopardizing the sustained real-time
  monitoring mission of the observing system.
• Buoy-mounted CODAR systems for expanded coverage,
  reduced error, and long-range ship tracking.

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Gulf of Maine Ecosystem Modeling
Fei CHAI Huijie Xue School of Marine
Sciences University of Maine
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Carbon, Silicate, Nitrogen Ecosystem
Model CoSiNE, Chai et al. 2002 Dugdale et al.
2002
Air-Sea Exchange
Small Phytoplankton P1
Micro- Zooplankton Z1
Biological Uptake
Total CO2 TCO2
Grazing
NO3 Uptake
NH4 Uptake
Predation
Nitrate NO3
Excretion
Ammonium NH4
Meso- zooplankton Z2
N-Uptake
Fecal Pellet
Advaction Mixing
Grazing
Fecal Pellet
Diatoms P2
Lost
Detritus-N DN
Detritus-Si DSi
Si-Uptake
Sinking
Physical Model
Silicate Si(OH)4
Dissolution
Sinking
Sinking
Chai et al., 2003 Jiang and Chai, 2004
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Welcome to the Gulf of Maine Ecosystem Modeling
Website (internal use only for now)
An ecosystem model embedded in the GoMOOS
circulation forecast model Physical-biological
model results need to be analyzed Ecosystem
model performance needs to be improved Daily
Nutrient and plankton forecast for the Gulf of
Maine
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On the horizon

• New instrument platforms Gliders, AUVs, SAVs,
  intelligent profiling floats.
• DNA probes to detect red tides and other harmful
  algal blooms, coliform bacteria. Dr. Laurie
  Connell, SMS University of Maine.
• Seamless observational and data base system
  integration of GoMOOS with other regional
  observing systems into a North American Observing
  system.

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• Slocum coastal glider
• 2-3 week mission duration in shallow water.
• Sensors CTD, Oxygen optode, fluorometer.

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Solar Auv

• 2 knot cruising speed
• extended missions on the order several days.
• Aprox 4-5 times the spatial coverage per unit
  time as compared with the glider.

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