about boon

About BOON




sensor platforms

Shoreline Observations

Offshore Mooring and Buoy Observations

High Frequency Radar

Vessel Based Observations

Resident Platforms

Products + Tools

All Real Time Observations

Sea Surface Currents

Research Products

Resource Managers

Recreation and Coastal Conditions


Summary of Data Sets

Data Access

Data Disclaimer & Terms of Use

Offshore Mooring and Buoy Observations > Cordell Bank Mooring

  • Description
  • Instruments/Sensors
  • Data Access

Cordell Bank Buoy cordell bank buoy axys platform

The Cordell Bank mooring was a collaboration between Bodega Marine Laboratory and Cordell Bank National Marine Sanctuary.

The mooring was in 85m, on the crest of Cordell Bank and about 20 nautical miles west of Point Reyes. Data are used by Cordell Bank National Marine Sanctuary staff, research oceanographers, and local communities to better understand offshore ocean conditions. Time series data from this mooring may provide a valuable record of fluctuations and change in the ocean environment that supports the highly productive marine ecosystem in this region.

Deployed: May 8, 2007 to May 27, 2008
Location: 38° 03.008’, 123° 27.374’

Instrument array: Seabird Electronics SBE-37 Microcat CT Recorder, Wetlabs ECO-FLNTUSB, Nortek Aquadopp, RM Young 05103 Wind Monitor
Measurements: salinity, conductivity, temperature, fluorescence, turbidity, water velocity, wind velocity
Site elevation: sea level
Array depth: 2.5m below site elevation
Water depth: 85m

Also see Cordell Bank buoy platform (deployed April 21, 2009 to August 19, 2013) >

Project Background

cordell bank

Cordell Bank provides productive habitat for many birds, mammals and fish, rising to within 35 meters of the surface of the ocean from the surrounding deeper waters (image, left). The bank is situated downstream from a major and persistent upwelling center at Point Arena to the north, but is occasionally impacted by outflows that arrive from San Francisco Bay to the south (image, below). Inter-annual and intra-annual variability in the various oceanographic influences can be expected to lead to variability in the productivity of the ecosystem associated with Cordell Bank.


cordell bank in contextResearchers at the Bodega Marine Laboratory (BML) and the Cordell Bank National Marine Sanctuary collaborated in the design and purchase of the Cordell Bank mooring. The project was funded through the Joint Institute of Marine Observations, now called Cooperative Institute on Marine Ecosystems and Climate (CIMEC), a collaborative institute between NOAA and the University of California. The project goals were: (1) to monitor and document physical and biological conditions on the Bank, (2) to increase understanding of the relationship between upwelling / productivity at the Bank and the physical forcing, and (3) to educate the public about oceanic processes, and this valuable Sanctuary in particular. The mooring sensors provided a record of chlorophyll fluorescence, turbidity, water temperature, salinity, and ocean current velocity over the Bank. In combination with the Cordell Bank Oceanographic Monitoring Program (CBOMP) monthly surveys, and the Bodega Ocean Observing Node (BOON) data, including HF radar mapping of surface currents, the mooring measurements will allow for much improved assessment, monitoring and understanding of the essential characteristics of this pelagic habitat. This effort is a component of the Central and Northern California Ocean Observing System (CeNCOOS).

Wind Speed and Direction

axys buoyInstrument Type: RM Young 05103 Wind Monitor

Description: The wind speed sensor is a four blade helicoid propeller. Propeller rotation produces an AC sine wave voltage signal with frequency directly proportional to wind speed.  The wind direction sensor is a rugged yet lightweight vane.  Vane angle is sensed by a precision potentiometer housed in a sealed chamber. With a known excitation voltage applied to the potentiometer, the output voltage is directly proportional to vane angle.

Location: Atop buoy mast at Northwest end of Cordell Bank
Latitude 38° 02' 55.8" N
Longitude 123° 27' 24.0" W

Installed:  May 8, 2007 - May 27, 2008

Specifications: Wind Speed
Range: 0 to 224 mph (0 to 100 m/s)
Accuracy: 0.6 mph ( 0.3 m/s) or 1% of reading
Propeller Distance Constant: 2.7 m (8.9 ft)
Starting Threshold: 2.2 mph (1 m/s)

Specifications: Wind Direction
Range: 0 to 355 degrees
Accuracy: ± 3 degrees
Dead Band: 5 degrees (355 to 360 degrees)
Starting Threshold: 2.4 mph (1.1 m/s)

Acquisition Settings:
Sample Rate: 1 Hz
10 minute vector average of speed and direction (magnetic) recorded once per hour
Peak wind speed (gust) recorded during 10 minute sample

Seawater Fluorescence & Turbidity CBNMS flourometer

Instrument Type:  WETLabs ECO FLTUS Fluorometer & Turbidity Sensor

Description:  Fluorescence data provide an approximation of phytoplankton abundance, which is an important component in the food chain.  Turbidity is a measure of water clarity.  The Environmental Characterization Optics, or ECO, FLNTUS is a dual-wavelength, single-angle sensor for simultaneously determining both chlorophyll fluorescence and turbidity.  This allows for assessment of fluorescence and turbidity variability and interactions.  This model also has an integrated anti-fouling bio-wiper™.

Location: Inside moon pool on buoy at Northwest end of Cordell Bank
Latitude 38° 02' 55.8" N
Longitude 123° 27' 24.0" W

Installed: May 8, 2007 - May 27, 2008

Specifications: Fluorescence
Excitation Wavelength:  470 nm
Emission Wavelength:  695 nm
Sensitivity:  0.01 µg/l
Linearity:  99% R2
Range:  0.01 – 50 µg/l

Specifications: Turbidity
Wavelength:  700 nm
Sensitivity:  0.01 NTU
Range:  0.01 – 25 NTU

Acquisition Settings:
10 minute average collected once per hour
Biowiper opens for sample

Seawater Temperature, Conductivity & Salinity

CBNMS ctdInstrument Type:  Sea-Bird Electronics SBE 37SIP MicroCAT

Description:  The SBE 37-SIP MicroCAT is a high-accuracy conductivity and temperature monitor with Serial Interface and integral Pump.  The MicroCAT uses a unique internal-field conductivity cell and an aged and pressure-protected thermistor that has a long history of exceptional accuracy and stability.  Salinity values are calculated from the 1978 Practical Salinity Scale Equations.  The integral pump typically runs for 0.5 seconds each time the MicroCAT samples. 

Location: Inside moon pool on buoy at Northwest end of Cordell Bank
Latitude 38° 02' 55.8" N
Longitude 123° 27' 24.0" W

Installed: May 8, 2007 - May 27, 2008

Specifications: Temperature
Range:  -5 to +35 °C
Resolution:  0.0001 °C
Accuracy:  0.002 °C

Specifications: Conductivity
Range:  0 to 7 S/m
Resolution:  0.00001 S/m
Accuracy:  0.0003 S/m

Acquisition Settings:
10 minute average collected once per hour

Acoustic Doppler Current Profiler - Current Velocity and Direction

CBNMS adcpInstrument Type: Nortek 400-kHz Aquadopp Profiler

Description: The Aquadopp® profiler measures the current profile in water using acoustic Doppler technology.  Three acoustic beams slanted at 25° accurately measure the current profile.  The instrument also houses internal tilt and compass sensors tell the current direction, as well as a temperature sensor and high-resolution pressure sensor.

Location: Inside moon pool on buoy at Northwest end of Cordell Bank
Latitude 38° 02' 55.8" N
Longitude 123° 27' 24.0" W

Installed: May 8, 2007 - May 27, 2008

Frequency:  400 kHz
Beam Width:  3.7°
Velocity range: ± 10 m/s
Accuracy: 1% of value, ± 0.5 cm/s
Echo intensity: 0.45 dB resolution
Profiling Range:  60 – 90 m

Acquisition Settings:
5 minute average collected once per hour
Sampling Rate:  1 Hz
Blanking Distance:  5 m
Bin Size:  4 m
Number of Bins:  20

Please contact bmldata@ucdavis.edu for data access information.