Metadata Report for BODC Series Reference Number 580697

• 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 quality

The temperature channel becomes noiser throught this dataset and there is a gradual increase in values from start to finish. This data should be used with caution.

Data Access Policy

Public domain data

These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.

The recommended acknowledgment is

"This study uses data from the data source/organisation/programme, provided by the British Oceanographic Data Centre and funded by the funding body."

Narrative Documents

Aanderaa Recording Current Meter Model 7/8

Manufacturer's specifications: recording unit height 49.5cm (RCM8 52.0cm), diameter 12.8cm, vane size 48.5x50.0cm. Meter is designed for depths down to 2000m (RCM8 6000m). It incorporates a spindle which is shackled to the mooring line. The meter is attached to the spindle through a gimbal mounting which permits a maximum 27° deviation of the spindle from the vertical, the meter still remaining horizontal.

Meter comprises :

1. Paddle wheel rotor magnetically coupled to an electronic counter

2. Vane, which aligns instrument with current flow, has a balance weight ensuring static balance and tail fins to ensure dynamic balance in flows up to 250cm/s.

3. Magnetic compass (needle is clamped to potentiometer ring) - direction recorded with 0.35° resolution, 5° accuracy for speeds 5 to 100cm/s, 7.5° accuracy for remaining speeds within 2.5 to 200cm/s range.

4. Quartz clock, accuracy better than 2 sec/day within temperature range 0 to 20°C.

5. Thermistor (temperature sensor), standard range -2.46 to 21.48°C (max on high range 36.04°C), accuracy 0.05°C, resolution 0.1 per cent of range, 63 per cent response time 12sec.

6. Inductive cell conductivity sensor (optional), range 0 to 70mmho/cm standard resolution 0.1 per cent of range.

7. Silicon piezoresistive bridge, standard range 0 to 3000 psi (RCM8 to 9000 psi), resolution 0.1% of range.

8. Self balancing potentiometer which converts the output from each sensor into a 10 bit binary number for storage on magnetic tape.

9. Associated electronics.

A built-in clock triggers the instrument at preset intervals and up to six channels are sampled in sequence. Channel 1 is a fixed reference reading for control purposes and data identification. Channels 2, 3 and 4 represent measurement of temperature, conductivity and pressure. Channels 5 and 6 represent the VECTOR AVERAGED current speed and direction since the previous triggering of the instrument. The number of rotor revolutions and the direction is sampled every 12 seconds and broken into North and East components. Successive components are added and recorded as speed and direction. For recording intervals longer than 10 minutes, speed and direction are sampled 1/50th of recording interval.

It has become common practice in some laboratories to deploy these meters as temperature and conductivity loggers without current measuring capabilities.

The following link will provide the manufacturer specifications:

BODC processing

The data were provided to BODC in ascii format and were transferred to qxf format by BODC produced Matlab transfer 136. The full dataset was made up from two files. One file contained velocity vectors in both the North/South direction and the East/West direction and temperature readings. The second file contained Salinity readings. The transfer converted the velocities to current speed and direction.

There were no headings included in the files to point to which channel refered to which variable. The files had suffixes of t or s to denote whether the last column was for temperature or salinity. The temperature file contained the current vectors. The vectors were resolved during transfer so no user activity is required for this conversion. The variables were then mapped to the appropriate BODC parameter code which can be seen below:

Following the transfer the data was screened using the BODC in-house visualisation software, EDSERPLO. Any suspect data points were flagged with the appropriate BODC flag code.

Originator's data processing

The data from the Vemco Miniloggers were merged to form "pseudo" thermistor chain records prior to being supplied to BODC.

FRS applied the standard manufaturers' calibrations to all data, and produced ascii files for submission to BODC.

Project Information

No Project Information held for the Series

Data Activity or Cruise Information

Data Activity

FRS moored Aanderaa recording current meter (RCM7) from off Loch Torridon

A moored Aanderaa Recording Current Meter (RCM7) was deployed by Fisheries Research Services (FRS) off Loch Torridon (57.63933° N, 5.94167° W) on 05/04/01 as part of the Clupea 0501c cruise, and recovered on 17/07/01 by the Clupea 0901c cruise. The station had a nominal water depth of 105 m. The RCM7 had a sampling period of 30 minutes. The data were supplied as current meter records at two discrete depths: series 6581 at 30 m and series 6582 at 95 m.

The mooring consisted of the following instruments.

Related Data Activity activities are detailed in Appendix 1

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

No Fixed Station Information held for the Series

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: 658

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.