Metadata Report for BODC Series Reference Number 610062

• Metadata Summary

• Problem Reports

• Data Access Policy

• Narrative Documents

• Project Information

• Data Activity or Cruise Information

• Fixed Station Information

• BODC Quality Flags

• SeaDataNet Quality Flags

Metadata Summary

Problem Reports

No Problem Report Found in the Database

Data Access Policy

Open Data supplied by Natural Environment Research Council (NERC)

You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."

Narrative Documents

TRB-1 and TRB-2 Self-recording Transmissometers

The TRB-1 self-recording transmissometer was designed by the School of Ocean Sciences, University of Wales, Bangor and was sometimes known as the 'Mark III Transmissometer'. The instrument was developed commercially by W.S. Ocean Systems Limited and marketed with the designation TRB-2.

The instrument used a 660nm (red) source modulated at 400 Hz. The optical assembly incorporated a folded beam design to reduce instrument size to a minimum. The light beam was collimated using an achromatic lens, passed through a fixed length of the water column and reflected back to a photodiode receiver via a prism reflector. The optical path length could be fixed at either 5 cm, 10 cm or 25 cm.

Data were logged at the top of each minute as the average of 200 samples taken at 400 Hz. Timing was based on an accurate real-time clock emulated by the processor BIOS extension. Data were acquired by a multi-channel 12- bit data acquisition system resident on the motherboard resulting in a count between 0 and 4095.

Data were stored internally on a 2 MByte SRAM card giving storage for 120 days of data. After deployment, the data were downloaded in a simple ASCII format onto a PC.

TRB-2 instruments could be fitted with additional conductivity and temperature sensors.

Project Information

North Sea Project

The North Sea Project (NSP) was the first Marine Sciences Community Research project of the Natural Environment Research Council (NERC). It evolved from a NERC review of shelf sea research, which identified the need for a concerted multidisciplinary study of circulation, transport and production.

The ultimate aim of the NERC North Sea Project was the development of a suite of prognostic water quality models to aid management of the North Sea. To progress towards water quality models, three intermediate objectives were pursued in parallel:

• Production of a 3-D transport model for any conservative passive constituent, incorporating improved representations of the necessary physics - hydrodynamics and dispersion;
• Identifying and quantifying non-conservative processes - sources and sinks determining the cycling and fate of individual constituents;
• Defining a complete seasonal cycle as a database for all the observational studies needed to formulate, drive and test models.

Proudman Oceanographic Laboratory hosted the project, which involved over 200 scientists and support staff from NERC and other Government funded laboratories, as well as seven universities and polytechnics.

The project ran from 1987 to 1992, with marine field data collection between April 1988 and October 1989. One shakedown (CH28) and fifteen survey cruises (Table 1), each lasting 12 days and following the same track, were repeated monthly. The track selected covered the summer-stratified waters of the north and the homogeneous waters in the Southern Bight in about equal lengths together with their separating frontal band from Flamborough head to Dogger Bank, the Friesian Islands and the German Bight. Mooring stations were maintained at six sites for the duration of the project.

Alternating with the survey cruises were process study cruises (Table 2), which investigated some particular aspect of the science of the North Sea. These included fronts (nearshore, circulation and mixing), sandwaves and sandbanks, plumes (Humber, Wash, Thames and Rhine), resuspension, air-sea exchange, primary productivity and blooms/chemistry.

In addition to the main data collection period, a series of cruises took place between October 1989 and October 1990 that followed up work done on previous cruises (Table 3). Process studies relating to blooms, plumes (Humber, Wash and Rhine), sandwaves and the flux of contaminants through the Dover Strait were carried out as well as two `survey' cruises.

The data collected during the observational phase of the North Sea Project comprised one of the most detailed sets of observations ever undertaken in any shallow shelf sea at that time.

North Sea Project Resuspension Process Study

The ratio of particulate to dissolved material which is so important to water quality is affected by resuspension which, in turn, depends on the character of the sea bed, biological influences, tidal currents, wind, wave and seasonal stratification. The objectives of the three resuspension cruises were to make time series observations of physical, sedimentological and biological properties of the sediment, suspended particle material and water at two sites in the North Sea, using a variety of moored instruments, CTD/water bottle casts, pumped sampling and sediment grabs and box cores.

The two sites were:

1. • Northern Site
   • 54° 35'N, 004° 50'E
   • 45m depth
   • muddy sand
   • seasonally stratified water column
2. • Southern Site
   • 52° 40'N, 003° 40'E
   • 27m depth
   • sand
   • permanently well-mixed water column

Data Activity or Cruise Information

Data Activity

North Sea Project POLRIG#60420

Deployment

This rig was deployed as part of the Resuspension experiments at the Southern site

Rig Description

The U-shaped mooring consisted of three Aanderaa current meters (RCM7) and three transmissometers (TR). A marker buoy was attached to the anchor, a ground line attached the anchor to a further anchor, and this was attached to a sub-surface buoy (0.8 m diameter steel sphere). The current meters and transmissometers were attached to this wire.

Related Data Activity activities are detailed in Appendix 1

Fixed Station Information

Fixed Station Information

North Sea Project Resuspension Experiment Southern Site

This site was one of two contrasting North Sea sites occupied during the North Sea Project Resuspension Experiment.

The southern site was located in 27m of water and was characterised by a sandy bed and a permanently well-mixed water column.

The rigs deployed here lie within a box bounded by co-ordinates 52.652N 3.653E at the southwest corner and 52.670N 3.680E the northeast corner. Magnetic variation at this site was 3.0 degrees west.

Southern site deployment history is summarised below:

ADCP = Acoustic Doppler Current Profiler
CM = Current Meter
PR = Pressure Recorder
TR = Transmissometer
TG = Tide Gauge
WV = Wave Rider
MET = Met. Buoy

Related Fixed Station activities are detailed in Appendix 2

BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Appendix 1: RIG#60420

Related series for this Data Activity are presented in the table below. Further information can be found by following the appropriate links.

If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.

Appendix 2: NSP Resusp. S

Related series for this Fixed Station are presented in the table below. Further information can be found by following the appropriate links.

If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.