Metadata Report for BODC Series Reference Number 604610
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
Data Description |
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Data Identifiers |
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Time Co-ordinates(UT) |
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Parameters |
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Problem Reports
No current speed or direction data are available for this series due to entanglement of the current meter.
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 :
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Paddle wheel rotor magnetically coupled to an electronic counter
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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.
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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.
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Quartz clock, accuracy better than 2 sec/day within temperature range 0 to 20°C.
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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.
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Inductive cell conductivity sensor (optional), range 0 to 70mmho/cm standard resolution 0.1 per cent of range.
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Silicon piezoresistive bridge, standard range 0 to 3000 psi (RCM8 to 9000 psi), resolution 0.1% of range.
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Self balancing potentiometer which converts the output from each sensor into a 10 bit binary number for storage on magnetic tape.
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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:
Manufacturer specificationsBODC Processing
Data were received by BODC in ASCII format files. This series was reformatted to the internal QXF format using BODC transfer function 325. The following table shows how the variables within the file were mapped to the appropriate BODC parameter codes.
Original parameter name | Original Units | Description | BODC Parameter Code | BODC Units | Comments |
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Time | DD/MM/YYYY HH:MI | date and time | AADYAA01 and AAFDZZ01 | day number and day fraction GMT | Conversion by transfer |
T | degrees Celsius | Temperature | TEMPPR01 | degrees Celsius | |
S | dimensionless | Salinity | PSALPR01 | dimensionless |
Following transfer to QXF, the data were screened using BODC's in-house visualisation software, EDSERPLO. Any data considered as suspect were flagged 'M'. Flags from the originator marking suspect data were retained during transfer and flagged 'L'.
Originator's Data Processing
Sampling Strategy
The Aanderaa RCM7 current meter deployed at Loch Sunart had a sampling frequency of 1 reading per hour. The instrument included temperature and conductivity sensors.
Data Processing
No current data were available for this instrument due to entanglement of the meter. DAF applied the standard manufacturers' calibrations to all temperature and salinity data. The salinity data underwent further processing to remove a 'jump' in the data at 03:00 hours on 28 December 2001, which was probably the result of material becoming attached to the conductivity sensor. Using a constant rate of change from the previous two salinity samples at 01:00 hours and 02:00 hours on 28 December 2001, an offset of 1.5193 was calculated. This offset was subtracted from all salinites from 03:00 hours on 28 December 2001 to the end of the record, producing a corrected salinity series, SALcorr. In addition, CTD profiles collected at various times throughout the deployment were used to derive a linear regression (least squares fit) that was subtracted from the entire series as follows:
SALdetr = SALcorr-(-0.00069*SALtime)
where SALtime is the time in hours from the beginning of the series. SALdetr and temperature data were submitted to BODC in ASCII files named according to the mooring code (671) and the instrument number (1). Temperature and salinity were supplied in separate files (append t and append s, respectively).
Project Information
No Project Information held for the Series
Data Activity or Cruise Information
Data Activity
Start Date (yyyy-mm-dd) | 2001-06-27 |
End Date (yyyy-mm-dd) | 2002-06-18 |
Organization Undertaking Activity | Fisheries Research Services Aberdeen Marine Laboratory (now Marine Scotland Aberdeen Marine Laboratory) |
Country of Organization | United Kingdom |
Originator's Data Activity Identifier | 671 |
Platform Category | subsurface mooring |
DAF Current Meter mooring, Loch Sunart
The mooring was located at 56° 41.17' N, 005° 37.00' W in a nominal water depth of 40 m.
The mooring was deployed on 27 June 2001 by the Department of Agriculture and Fisheries (DAF, now known as Marine Scotland Aberdeen Marine Laboratory) using a small boat, recovered on 18 June 2002, and consisted of the following instruments.
Instrument type | Serial Number | Deployment start | Deployment end | Instrument depth (m) | Comments |
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Aanderaa RCM 7 | 7596 | 2001-06-27 | 2002-06-18 | 37 | No current data due to meter entanglement. Temperature and salinity data available. |
Cruise
Cruise Name | Sunart2001 |
Departure Date | 2001-06-26 |
Arrival Date | 2001-06-29 |
Principal Scientist(s) | |
Ship | Unknown self-propelled boat |
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:
Flag | Description |
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Blank | Unqualified |
< | Below detection limit |
> | In excess of quoted value |
A | Taxonomic flag for affinis (aff.) |
B | Beginning of CTD Down/Up Cast |
C | Taxonomic flag for confer (cf.) |
D | Thermometric depth |
E | End of CTD Down/Up Cast |
G | Non-taxonomic biological characteristic uncertainty |
H | Extrapolated value |
I | Taxonomic flag for single species (sp.) |
K | Improbable value - unknown quality control source |
L | Improbable value - originator's quality control |
M | Improbable value - BODC quality control |
N | Null value |
O | Improbable value - user quality control |
P | Trace/calm |
Q | Indeterminate |
R | Replacement value |
S | Estimated value |
T | Interpolated value |
U | Uncalibrated |
W | Control value |
X | Excessive difference |
SeaDataNet Quality Control Flags
The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:
Flag | Description |
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0 | no quality control |
1 | good value |
2 | probably good value |
3 | probably bad value |
4 | bad value |
5 | changed value |
6 | value below detection |
7 | value in excess |
8 | interpolated value |
9 | missing value |
A | value phenomenon uncertain |
B | nominal value |
Q | value below limit of quantification |