Metadata Report for BODC Series Reference Number 1804056
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
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Problem Reports
No Problem Report Found in the Database
Data Access Policy
Open 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.
If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:
"Contains public sector information licensed under the Open Government Licence v1.0."
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 specificationsDML Aanderaa RCM current meter data: Originator's data processing
Summary of DML (formerly SMBA) Standard Procedures for Current Meter Data
Mooring System for Water Depths up to 200m
U shaped mooring i.e. pellet float to pellet line to sub-surface buoy to meter mooring line (with either in-line or A-frame mounting of meters) to anchor weight to ground line to anchor weight to marker buoy tow chain, then line to surface spar marker buoy and to pellet line and floats. The mooring is deployed in the order given and recovered in reverse order. Usually lengths of main wires are: buoy tow line D-15m, buoy tow chain 55m, sometimes buoy line is all chain, (prior to 1977 buoy tow line 2D used without chain), ground wire 2D (but never less than 150m), meter rope (excluding sub-surface buoy bridles and anchor bridles) D-X-3m where D is the depth of water and X is the depth of the sub-surface buoy. Generally X=30m but this may vary depending on the application of the mooring and the requirement for near surface current measurements. The mooring site is chosen by echo sounding to accord with the preset length of instrument line; however occasionally the length of the instrument line is adjusted on station. The site is positioned to an accuracy of 0.5nm using either Decca main chain, Loran or Satellite Navigation (GPS), depending on reception etc.
Data Processing
Speed is integrated over the sampling interval. Direction and, where measured, temperature and pressure, are taken as spot measurements at the end of the sampling interval. Direction is corrected for magnetic variation. Pressure measurements are not corrected for atmospheric pressure.
Parameter values i.e. speed, temperature and pressure are given at times incremented by the sample interval. The time assigned to each parameter is that of the end of the sampling interval. Time values are corrected for clock error should this occur.
Sea floor depths are relative to the instantaneous sea surface i.e. obtained from corrected echo soundings at the time of rig deployment (Matthew's corrections are applied).
Calibrations
Each meter is calibrated against the manufacturer's formulae for direction and Plessey meters are calibrated for temperature; Aanderaa meters use the manufacturer's temperature calibrations. The manufacturer's velocity and pressure calibrations are used.
DML Aanderaa RCM current meters: BODC data processing
Data from 7 Aanderaa RCM current meters arrived at BODC in ASCII format.
Data were reformatted to a standard BODC format. The following table shows how the variables within the data files were mapped to appropriate standard BODC parameter codes:
Originator's Variable | Units | Description | BODC Parameter Code | Units | Comment |
---|---|---|---|---|---|
Northward current velocity | Centimetres per second | Northward current velocity (Eulerian) in the water body by in-situ current meter | LCNSEL01 | Centimetres per second | - |
Eastward current velocity | Centimetres per second | Eastward current velocity (Eulerian) in the water body by in-situ current meter | LCEWEL01 | Centimetres per second | - |
Temperature | Degrees Celsius | Temperature of the water body | TEMPPR01 | Degrees Celsius | - |
Pressure | Decibars | Pressure (measured variable) exerted by the water body by semi-fixed in-situ pressure sensor and corrected to read zero at sea level | PREXPR01 | Decibars | - |
Salinity | psu | Practical salinity of the water body by conductivity cell and computation using UNESCO 1983 algorithm | PSALPR01 | dimensionless | Only applies to serial/rig - 8217/240, 8580/243 and 8217/246 |
The reformatted data were visualised using BODC's in-house visualisation software. Suspect data were marked by adding an appropriate quality control flag, missing data by both setting the data to an appropriate value and setting the quality control flag.
Project Information
No Project Information held for the Series
Data Activity or Cruise Information
Data Activity
Start Date (yyyy-mm-dd) | 1989-08-04 |
End Date (yyyy-mm-dd) | 1989-11-20 |
Organization Undertaking Activity | Dunstaffnage Marine Laboratory (now Scottish Association for Marine Science) |
Country of Organization | United Kingdom |
Originator's Data Activity Identifier | Tiree#246 |
Platform Category | subsurface mooring |
Dunstaffnage Marine Laboratory Moored Instrument Rig#246
This rig was deployed in the Tiree Passage at site Y. The deployment forms part of the moored current meter series in the Tiree Passage, from 1981 to present.
Rig Position | 56° 37.1' N, 06° 24.3' W |
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Time Series Start/Deployment Vessel | 4 Aug 1989 14:00 from cruise RV Lough Foyle LF2/89 |
Time Series End /Recovery Vessel | 20 Nov 1989 09:29 |
The instruments formed a U-shaped mooring anchored by two 450kg weights, connected by a 100 metre ground wire. A spar marker buoy was attached to one of the weights, with a recovery line. The instruments, attached to the second weight, were held erect by a sub-surface buoy.
Instruments deployed on the rig
Height above Sea Bed | Instrument |
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11m | Aanderaa current meter (#8217) |
22m | Aanderaa current meter (#9177) |
Both instruments were fitted with temperature and salinity sensors.
Related Data Activity activities are detailed in Appendix 1
Cruise
Cruise Name | LF2/89 |
Departure Date | 1989-08-04 |
Arrival Date | 1989-08-10 |
Principal Scientist(s) | David J Ellett (Dunstaffnage Marine Laboratory) |
Ship | RV Lough Foyle |
Complete Cruise Metadata Report is available here
Fixed Station Information
Fixed Station Information
Station Name | DML Tiree Passage Mooring |
Category | Offshore location |
Latitude | 56° 37.20' N |
Longitude | 6° 24.00' W |
Water depth below MSL | 50.0 m |
Tiree Passage Mooring
The Tiree Passage Mooring (also referred to as Y Mooring) is a current meter mooring at 56° 37.2' N, 6° 24.0' W. It has been maintained by the Dunstaffnage Marine Laboratory (DML)/ Scottish Association for Marine Science (SAMS) since 1981. The mooring is serviced approximately 3 times a year. The Tiree Passage Mooring is the longest moored time series of flow and temperature on the NW European continental shelf.
Between 21/05/1993 and 17/09/1997 the mooring included two Aanderaa current meters located 11 m and 22 m above the sea floor except for the period between 09/05/1994 and 15/08/1994 when there was no top current meter. The proportion of good data returned was exceptionally high.
Gaps in the time series are caused by fluctuations in funding, mooring losses and instrument failures (additional gaps in the current time series, usually due to fouling of mechanical current meters).
Although conductivity sensors were fitted to the Aanderaa current meters from 1994 to 1997, the reliability of these sensors over long periods is questionable, and more work needs to be done in cross calibrating the calculated salinity against the salinity of coincident 'Ellett Line/Extended Ellett Line' CTD casts.
It should be noted that some data were submitted to BODC from PML and not DML. This was due the relocation of the Principal Investigator responsible for the data. He subsequently returned to DML.
Summary of Key Activities
Date | Activity |
---|---|
1981 | Tiree mooring is first deployed |
June 1981 | Hourly current and temperature measurements using Aanderaa recording current meters (RCMs) recorded at the bottom of the mooring (11 m above the bed) |
November 1987 | Addition of Aanderaa recording current meters (RCMs) at 22 m above the bed |
September 1993 | Hourly salinity measurements started to be taken at both depths using Aanderaa conductivity sensors |
September 1997 | Collection of data at both depths stops |
Between June 1999 and February 2000 | The mooring was re-deployed |
May 2002 until the present | Mooring is fitted with RCMs at both 20 m and 45 m above the bed. |
August 2002 | A Seabird MicroCAT salinity sensor was added at 20 m above bed. |
Figure 1: Map showing the locations of the Tiree mooring data time series.
Figure 2: The typcial set up of the Tiree mooring.
References
Inall, M. and Griffiths, C., 2003 The Tiree Passage Time Series: 1981-2003 DEFRA MECN: Tiree Passage
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:
Flag | Description |
---|---|
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 |
---|---|
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 |
Appendix 1: Tiree#246
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.
Series Identifier | Data Category | Start date/time | Start position | Cruise |
---|---|---|---|---|
1804044 | Currents -subsurface Eulerian | 1989-08-04 14:00:00 | 56.61833 N, 6.405 W | RV Lough Foyle LF2/89 |
Appendix 2: DML Tiree Passage Mooring
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.
Series Identifier | Data Category | Start date/time | Start position | Cruise |
---|---|---|---|---|
46857 | Currents -subsurface Eulerian | 1983-02-19 11:15:00 | 56.6179 N, 6.3983 W | Not applicable |
46869 | Currents -subsurface Eulerian | 1983-05-30 04:15:00 | 56.6266 N, 6.3964 W | Not applicable |
60666 | Currents -subsurface Eulerian | 1984-06-26 17:15:00 | 56.6217 N, 6.3967 W | RRS Challenger CH2/84 |
249384 | Currents -subsurface Eulerian | 1985-01-28 18:45:06 | 56.63 N, 6.4017 W | RRS Challenger CH1/85 |
249396 | Currents -subsurface Eulerian | 1985-05-07 22:00:00 | 56.62 N, 6.4 W | RRS Challenger CH4/85 |
60863 | Currents -subsurface Eulerian | 1985-08-19 09:00:00 | 56.625 N, 6.4 W | RRS Challenger CH8/85 |
60967 | Currents -subsurface Eulerian | 1985-12-15 17:00:00 | 56.6167 N, 6.4 W | RRS Frederick Russell FR13/85 |
61018 | Currents -subsurface Eulerian | 1986-03-21 21:00:00 | 56.619 N, 6.4065 W | RRS Charles Darwin CD10B |
61092 | Currents -subsurface Eulerian | 1986-06-14 19:00:00 | 56.6233 N, 6.4033 W | MV Dawn Sky DSK1/86 |
249403 | Currents -subsurface Eulerian | 1987-01-09 16:00:06 | 56.6267 N, 6.3867 W | RRS Challenger CH9 |
249102 | Currents -subsurface Eulerian | 1987-05-01 13:00:00 | 56.6183 N, 6.4167 W | RRS Challenger CH14 |
249187 | Currents -subsurface Eulerian | 1987-09-01 09:00:00 | 56.625 N, 6.405 W | RRS Frederick Russell FR18/87 |
249280 | Currents -subsurface Eulerian | 1987-11-29 14:30:06 | 56.63 N, 6.41 W | RRS Challenger CH22 |
249292 | Currents -subsurface Eulerian | 1987-11-29 14:30:06 | 56.63 N, 6.41 W | RRS Challenger CH22 |
249323 | Currents -subsurface Eulerian | 1988-03-07 12:00:00 | 56.625 N, 6.415 W | RRS Challenger CH25 |
249311 | Currents -subsurface Eulerian | 1988-03-07 12:00:06 | 56.625 N, 6.415 W | RRS Challenger CH25 |
1803993 | Currents -subsurface Eulerian | 1988-06-08 15:00:00 | 56.62833 N, 6.40333 W | RRS Challenger CH30 |
1804007 | Currents -subsurface Eulerian | 1988-06-08 15:00:00 | 56.62833 N, 6.40333 W | RRS Challenger CH30 |
1804019 | Currents -subsurface Eulerian | 1989-01-23 16:30:06 | 56.62667 N, 6.39167 W | RRS Discovery D180 |
1804020 | Currents -subsurface Eulerian | 1989-01-23 16:30:06 | 56.62667 N, 6.39167 W | RRS Discovery D180 |
1804032 | Currents -subsurface Eulerian | 1989-05-05 11:30:06 | 56.61667 N, 6.40333 W | RV Lough Foyle LF1/89 |
1804044 | Currents -subsurface Eulerian | 1989-08-04 14:00:00 | 56.61833 N, 6.405 W | RV Lough Foyle LF2/89 |
508056 | Currents -subsurface Eulerian | 1993-05-21 08:45:00 | 56.6283 N, 6.3967 W | RRS Challenger CH103 |
508308 | Currents -subsurface Eulerian | 1993-05-21 08:45:06 | 56.6283 N, 6.3967 W | RRS Challenger CH103 |
508068 | Currents -subsurface Eulerian | 1993-09-10 14:30:06 | 56.6255 N, 6.4018 W | RRS Challenger CH105 |
508136 | Currents -subsurface Eulerian | 1993-09-10 14:30:06 | 56.6255 N, 6.4018 W | RRS Challenger CH105 |
508044 | Currents -subsurface Eulerian | 1994-03-14 19:30:06 | 56.6267 N, 6.4033 W | RRS Challenger CH110 |
508081 | Currents -subsurface Eulerian | 1994-05-09 14:45:06 | 56.6283 N, 6.3983 W | RRS Challenger CH112 |
508148 | Currents -subsurface Eulerian | 1994-05-09 14:45:06 | 56.6283 N, 6.3983 W | RRS Challenger CH112 |
508032 | Currents -subsurface Eulerian | 1994-08-15 21:15:00 | 56.62 N, 6.4017 W | RRS Challenger CH114 |
508204 | Currents -subsurface Eulerian | 1994-08-15 21:15:06 | 56.62 N, 6.4017 W | RRS Challenger CH114 |
508093 | Currents -subsurface Eulerian | 1994-11-28 13:45:17 | 56.62 N, 6.4 W | RRS Challenger CH116 |
508161 | Currents -subsurface Eulerian | 1994-11-28 14:15:05 | 56.62 N, 6.4 W | RRS Challenger CH116 |
508228 | Currents -subsurface Eulerian | 1995-04-14 14:45:06 | 56.6183 N, 6.3933 W | RRS Charles Darwin CD92B |
508277 | Currents -subsurface Eulerian | 1995-04-14 14:45:06 | 56.6183 N, 6.3933 W | RRS Charles Darwin CD92B |
508100 | Currents -subsurface Eulerian | 1995-07-29 14:45:00 | 56.6177 N, 6.4062 W | RRS Challenger CH120 |
508173 | Currents -subsurface Eulerian | 1995-07-29 14:45:00 | 56.6177 N, 6.4062 W | RRS Challenger CH120 |
508241 | Currents -subsurface Eulerian | 1996-01-19 18:15:06 | 56.6217 N, 6.3883 W | RRS Challenger CH124 |
508289 | Currents -subsurface Eulerian | 1996-01-19 18:15:06 | 56.6217 N, 6.3883 W | RRS Challenger CH124 |
508112 | Currents -subsurface Eulerian | 1996-05-16 19:15:06 | 56.622 N, 6.4042 W | Not applicable |
508185 | Currents -subsurface Eulerian | 1996-05-16 19:15:06 | 56.622 N, 6.4042 W | Not applicable |
508290 | Currents -subsurface Eulerian | 1996-09-16 15:15:00 | 56.6217 N, 6.4083 W | Not applicable |
508253 | Currents -subsurface Eulerian | 1996-10-07 07:15:00 | 56.6217 N, 6.4083 W | Not applicable |
508197 | Currents -subsurface Eulerian | 1997-04-30 13:15:06 | 56.625 N, 6.4 W | Not applicable |
508265 | Currents -subsurface Eulerian | 1997-04-30 13:15:06 | 56.625 N, 6.4 W | Not applicable |
508124 | Currents -subsurface Eulerian | 1997-07-16 12:15:06 | 56.625 N, 6.3967 W | Not applicable |
508216 | Currents -subsurface Eulerian | 1997-07-16 12:15:06 | 56.625 N, 6.3967 W | Not applicable |
1805084 | Currents -subsurface Eulerian | 2002-05-09 22:00:00 | 56.6283 N, 6.396 W | Not applicable |
1805096 | Currents -subsurface Eulerian | 2002-08-20 22:00:00 | 56.6283 N, 6.396 W | Not applicable |
1805047 | Currents -subsurface Eulerian | 2002-12-10 16:00:00 | 56.6283 N, 6.396 W | Not applicable |
1805072 | Currents -subsurface Eulerian | 2003-03-12 21:00:00 | 56.6283 N, 6.396 W | Not applicable |
1805059 | Currents -subsurface Eulerian | 2003-05-01 16:00:00 | 56.6283 N, 6.396 W | Not applicable |
1805035 | Currents -subsurface Eulerian | 2003-06-27 12:00:00 | 56.6283 N, 6.396 W | Not applicable |
1805060 | Currents -subsurface Eulerian | 2003-08-22 13:00:00 | 56.6283 N, 6.396 W | Not applicable |
1804855 | Currents -subsurface Eulerian | 2004-01-15 19:00:00 | 56.6283 N, 6.396 W | Not applicable |
1804867 | Currents -subsurface Eulerian | 2004-05-26 15:00:00 | 56.6283 N, 6.396 W | Not applicable |
1804879 | Currents -subsurface Eulerian | 2004-12-07 18:00:00 | 56.6283 N, 6.396 W | Not applicable |
1804880 | Currents -subsurface Eulerian | 2005-02-25 15:00:00 | 56.6283 N, 6.396 W | Not applicable |
1804892 | Currents -subsurface Eulerian | 2005-05-03 17:00:00 | 56.6283 N, 6.396 W | Not applicable |
1805023 | Currents -subsurface Eulerian | 2005-06-23 23:00:00 | 56.6283 N, 6.396 W | Not applicable |
1805103 | Currents -subsurface Eulerian | 2005-11-22 16:00:00 | 56.6283 N, 6.396 W | Not applicable |
1805115 | Currents -subsurface Eulerian | 2006-04-27 22:00:00 | 56.6283 N, 6.396 W | Not applicable |
1804911 | Currents -subsurface Eulerian | 2007-05-09 16:00:00 | 56.6283 N, 6.396 W | Not applicable |
1804923 | Currents -subsurface Eulerian | 2007-09-28 13:00:00 | 56.6283 N, 6.396 W | Not applicable |
1804984 | Currents -subsurface Eulerian | 2008-02-13 15:00:00 | 56.6283 N, 6.396 W | Not applicable |
1804935 | Currents -subsurface Eulerian | 2008-09-24 19:00:00 | 56.6283 N, 6.396 W | Not applicable |
1804996 | Currents -subsurface Eulerian | 2009-02-24 20:00:00 | 56.6283 N, 6.396 W | Not applicable |
1804947 | Currents -subsurface Eulerian | 2009-06-03 15:00:00 | 56.6283 N, 6.396 W | Not applicable |
1804959 | Currents -subsurface Eulerian | 2010-01-07 17:00:00 | 56.6283 N, 6.396 W | Not applicable |
1804960 | Currents -subsurface Eulerian | 2010-09-20 17:00:00 | 56.6283 N, 6.396 W | Not applicable |
1804972 | Currents -subsurface Eulerian | 2011-02-16 20:00:00 | 56.6283 N, 6.396 W | Not applicable |
1805011 | Currents -subsurface Eulerian | 2011-07-21 20:00:00 | 56.6283 N, 6.396 W | Not applicable |