Metadata Report for BODC Series Reference Number 1618209

Metadata Summary

Data Description

Data Category Currents -subsurface Eulerian
Instrument Type
Aanderaa RCM 11 Recording Current Meter  current meters
Instrument Mounting subsurface mooring
Originating Country United Kingdom
Originator Mr Povl Abrahamsen
Originating Organization British Antarctic Survey
Processing Status banked
Project(s) BAS Long Term Monitoring and Survey

Data Identifiers

Originator's Identifier OP2_1113_3_RCM11_521_2349M
BODC Series Reference 1618209

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2011-03-27 15:00
End Time (yyyy-mm-dd hh:mm) 2013-03-31 13:51
Nominal Cycle Interval 3600.0 seconds

Spatial Co-ordinates

Latitude 60.63835 S ( 60° 38.3' S )
Longitude 42.17268 W ( 42° 10.4' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth 2349.0 m
Maximum Sensor Depth 2349.0 m
Minimum Sensor Height 762.0 m
Maximum Sensor Height 762.0 m
Sea Floor Depth 3111.0 m
Sensor Distribution Fixed common depth - All sensors are grouped effectively at the same depth which is effectively fixed for the duration of the series
Sensor Depth Datum Approximate - Depth is only approximate
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface


BODC CODE Rank Units Short Title Title
AADYAA01 1 Days Date(Loch_Day) Date (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ01 1 Days Time(Day_Fract) Time (time between 00:00 UT and timestamp)
ACYCAA01 1 Dimensionless Record_No Sequence number
CNDCZZ01 1 Siemens per metre Cond Electrical conductivity of the water body
LCDAZZ01 1 Degrees True UnspCurrDir Current direction in the water body
LCEWZZ01 1 Centimetres per second CurrVelE Eastward current velocity in the water body
LCNSZZ01 1 Centimetres per second CurrVelN Northward current velocity in the water body
LCSAZZ01 1 Centimetres per second UnspCurrSpd Current speed (Eulerian) in the water body
TEMPPR01 1 Degrees Celsius Temp Temperature of the water body
ZNTHSS01 1 Degrees ISTilt Orientation (tilt) of measurement platform by inclinometer

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

Problem Reports

No Problem Report Found in the Database

Orkney Passage OP2 mooring Data Quality Report

Screening and Quality Control

During screening procedures it became apparent that data logging did not occur as expected. Several gaps were identified in one instrument in this mooring.

It was confirmed that these issues were also present in the raw files, excluding the possibility of a data processing issue. Given that it is not clear which timestamp was recorded correctly, it was decided to remove the duplicate times from the final file.

Anomalous data values were also flagged M. See below for more detailed information of affected periods:

Period Comment
Series Reference Number 1618154
12/03/2007 04:59:00 to 15/03/2007 04:59:00 PSALPR01
12/03/2007 04:59:00 to 14/03/2007 05:59:00 CNDCZZ01 (several cycles flagged)
06/01/2008 20:55:00 to 07/01/2008 05:55:00 CNDCZZ01 and PSALPR01
01/02/2008 14:54:00 to 15:54:00 CNDCZZ01 and PSALPR01
11/06/2008 08:52:00 to 12/06/2008 20:52:00 CNDCZZ01 and PSALPR01
21/06/2008 03:52:00 to 21/06/2008 05:52:00 CNDCZZ01 and PSALPR01
29/12/208 13:49:00 to 09/01/2009 18:49:00 CNDCZZ01 and PSALPR01
Series Reference Number 1618166
25/02/2007 18:59:00 to 01/03/2007 10:59:00 PSALPR01
25/02/2007 18:59:00 to 26/02/2007 00:59:00 CNDCZZ01
Series Reference Number 1618178
04/08/2009 16:57:48 CNDCZZ01 and TEMPPR01
14/12/2010 12:54:00 to 13:54:00 CNDCZZ01
27/01/2011 01:53:40 to 27/01/2011 08:53:40 CNDCZZ01
30/11/2010 00:54:07 ZNTHSS01
Series Reference Number 1618191
02/03/2009 23:00:03 to 04/03/2009 01:00:05 CNDCZZ01
01/11/2009 21:04:49 to 01/11/2009 23:04:49 CNDCZZ01
Series Reference Number 1618209
31/05/2011 06:59:14 CNDCZZ01
04/06/2012 04:54:52 to 04/06/2012 15:54:52 CNDCZZ01
21/01/2012 00:56:28 to end of series several gaps in data

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

Aanderaa Recording Current Meter Model 9/11

The RCM 9/11 is a family of single-point Doppler recording current meters with different casing options to allow working at depths of up to 300 (RCM 9 LW), 2000 (RCM 9 IW) or 6000 (RCM 11) metres. The recording unit is 51.3 cm or 59.5 cm high (RCM 9 and RCM 11, respectively) with a diameter of 12.8 cm.

The RCM is most commonly deployed in an in-line mooring configuration. As it operates under a tilt up to 35° from vertical, it has a variety of in-line mooring applications by use of surface buoy or sub surface buoy. The instrument is installed in a mooring frame that allows easy installation and removal of the instrument without disassembly of the mooring line. The instrument can also be used for direct reading of the various parameters. This is conveniently done due to its compact design, low drag force and easy handling. Data can be stored internally and read after retrieval or be read in real time on deck by use of the profiling cable.

Meter comprises:

A built-in quartz clock allows the time of the first measurement to be recorded in the DSU. The measuring system is made up of a self-balancing bridge with sequential measurement of 10 channels and solid state memory. Channel 1 is a fixed reference reading for control purposes and data identification. Channels 2 and 3 represent measurement of current speed and direction. The direction is found by the use of measurements along two orthogonal axis and linking them to true north by use of an internal compass reading. The instrument can operate continuously or in eight intervals from 1 to 120 minutes. At 60-minute recording interval the operating time is more than two years. The current speed and direction are averaged over the measuring interval. Channels 4, 5 and 6 represent temperature, conductivity and pressure respectively.

Further information can be found in the manufacturer's instrument specification .

BODC Data Processing

Data Processing

The data arrived at BODC as individual .mat files containing data collected on moorings OP1, OP2, OP3, OP4, OP5, OP6, CI1 and CI2. They were submitted as part of an accession including 5 different instruments - Aquadopp, RCM8, RCM11, SBE37 and SBE39.


Parameters in the originator's files were reformatted into an internal file format using BODC standard procedures.

Some variables included in the RCM11 files have not been reformatted into the internal format files, as they will be stored as metadata. These include - botdepth (meters), date, lat (degrees north), lon (degrees east), mooringname, nomdepth (meters), serial_no and type.

The following table lists all the parameters included in the internal format files, showing how the originator's variables as named in the matlab files were mapped to appropriate BODC parameter codes.

Originator's Variable Originator's Units Description BODC Parameter Code BODC Units Comments
speed cm s -1 Current speed (Eulerian) in the water body LCSAZZ01 cm s -1


dir degrees magnetic Current direction in the water body LCDAZZ01 degrees true


u cm s -1 Eastward current velocity in the water body LCEWZZ01 cm s -1


v cm s -1 Northward current velocity in the water body LCNSZZ01 cm s -1


tilt degrees Orientation (tilt) of measurement platform by inclinometer ZNTHSS01 degrees


temp deg. C Temperature of the water body TEMPPR01 degrees C


cond mS cm -1 Electrical conductivity of the water body CNDCZZ01 S m -1 1:0.1 conversion from mS cm -1 to S m -1
salt - Practical salinity of the water body by conductivity cell and computation using UNESCO 1983 algorithm PSALPR01 - Only present in certain files. See note below

No derived parameters were calculated by BODC. Please note that the Salt parameter was only present in the files with series reference number 1618129, 1618130, 1618142, 1618154, 1618166.


Quality control flags were automatically added to data outside the expected parameter specific range during the reformatting process. All parameters were then visualised and screened using in house software, and any improbable or missing data point was assigned a quality control flag. The signal return amplitude 'sigstr' was reformatted for screening purposes only; as it is not an environmental variable, this parameter is not included in the final reformatted files, however it can be retrieved upon request.


Fofonoff and Millard (1983). Algorithms for computations of fundamental properties of seawater. UNESCO Technical Papers in Marine Science No 44, 53pp.

Originator's Data Processing

Sampling Strategy

Sampling was carried out as part of the BAS LTMS (British Antarctic Survey Long Term Monitoring and Survey). The project involved the deployment of moorings CI1, CI2, OP1, OP2, OP3, OP4, OP5 and OP6 in the Southern Ocean, situated north of Coronation Island and the Orkney Passage in the Weddell and Scotia Sea.

Moorings OP2, OP4, CI1 and CI2 were first deployed in 2005, fitted with RCM11 instruments, and data have been collected at 60-minute intervals since then. Gaps in the series may be caused by either instruments not being recovered, or data not being collected due to instrument malfunction.

Data Processing

Little information is known with regards to the exact details of the calibrations carried out on the mooring data. Data processing, visualisation and calibration were carried out through the use of scripts for Matlab version R2014b produced and ran by the originator.

The originator reported that current direction and velocity components were not corrected for magnetic variation, as at the moorings' sites this is lower than the measurements' accuracy. The Originator also reported that under some conditions the RCM11s under-read current speeds compared with a mechanical Vector Measuring Current Meter (VMCM), as indicated by results from Watts et al. (2013, J Atmos. Oceanic Technol.). Due to continuing uncertainties regarding which correction would best resolve the different characteristics of these two instruments, the RCM11 measurements were left unmodified by the Originator.

Offsets were applied to RCM11 temperature data in two datasets:

Mooring Time period (UT) Depth Serial Number Offset Applied
OP2 2007-02-25 to 2009-02-28 2385 m 592 0.0500 deg. C
OP4 2011-03-27 to 2012-07-25 2194 m 532 0.0170 deg. C


Watts D.R. et al., 2013. Four current meter models compared in strong currents in the Drake Passage. Journal of Atmospheric and Oceanic Technology: 30, 2465-2477. DOI: 10.1175/JTECH-D-13-00032.1

Project Information

BAS Long Term Monitoring and Survey


The Long Term Monitoring and Survey project (LTMS) has been running since the British Antarctic Survey (BAS) was created. This project is one of the BAS core projects, with several groups of scientists collecting various types of data e.g biological, geological, atmospheric, among others.

Data collection is achievable through a wide scope of instruments and platforms, e.g. the Antarctic research stations, autonomous instrument platforms deployed on or from BAS research ships, BAS aircrafts, satellite remote sensing and others.

Scientific Objectives

This project was implemented in order to measure change and variability in the Earth system. Its long term duration allows for the monitoring of processes that could be missed in shorter term studies and experiments. The data collected is also used to check and improve the reliability of models used to stimulate and predict the behavior of the Earth system.

The main objectives are:

Data Availability

The data sets obtained through this project are available to the academic community.

Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2011-03-27
End Date (yyyy-mm-dd) 2013-04-30
Organization Undertaking ActivityBritish Antarctic Survey
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierOP2
Platform Categorysubsurface mooring

Orkney Passage mooring 2 (OP2)

The mooring was deployed at the following positions:

Organisation Undertaking Activity British Antarctic Survey, Cambridge
Country of Organisation United Kingdom
Originator's Data Activity Identifier OP2
Platform Category Subsurface mooring
Latitude (+ve N) -60.6384
Longitude (+ve E) -42.1727
Water Depth (m) 3094

The mooring was deployed on the Orkney Passage on cruise JR20110319 (JR252, JR254C) on 27 March 2011 and recovery was done on cruise JR20130317 (JR272B, JR273A, JR281, UKD-4) on 30 April 2013.

The table below lists the instruments deployed on this mooring:

Instrument type Serial Number Data start (UT) Data end (UT) Instrument depth (m)
Sea Bird SBE37 2956 2011-03-27 14:15:00 2013-03-31 14:30:00 1594
Aquadopp 6263 2011-03-27 14:15:00 2013-03-31 14:30:00 1700
Aanderaa RCM11 521 2011-03-27 14:59:59 2013-03-31 13:51:19 2349
Sea Bird SBE37 7381 - - -
Aquadopp 6112 2011-03-27 14:15:00 2013-03-31 14:30:00 3062
Sea Bird SBE37 7380 2011-03-27 14:15:01 2013-03-31 14:30:00 3090

Data issues upon recovery

The recovery for this mooring presented some difficulties due to the presence of ice. Several floatation buoys were dragged under floes. No data were recovered for SBE37 SN 7381 due to the start command not being sent to the instrument before deployment.

Other Series linked to this Data Activity - 1223428 1362791 1362778 1223416


Cruise Name JR20110319 (JR252, JR254C)
Departure Date 2011-03-19
Arrival Date 2011-04-06
Principal Scientist(s)Povl Abrahamsen (British Antarctic Survey)
Ship RRS James Clark Ross

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

Station NameOrkney Passage OP2
CategoryOffshore location
Latitude60° 39.64' S
Longitude42° 9.41' W
Water depth below MSL2815.0 m

Orkney Passage OP2 site

Site OP2 is part of the Orkney Passage mooring array which is an activity covered by the Long Term Monitoring and Survey British Antarctic Survey's (BAS) programme. The data collection is the result of an ongoing collaboration between BAS and the Lamont-Doherty Earth Observatory (LDEO).

This site has been occupied since 2007 but throughout the years it has been moved. The recovery/deployment history, including position details, is presented below:

Deployed Recovered
Year Cruise Year Cruise Latitude (+veN) Longitude (+ve E) Water Depth (m)
2007 ES20070116 (ES031, ES038, ES048) 2009 ES033a -60.6606 -42.1568 2815
2009 ES033a 2011 JR20110319 (JR252, JR254C) -60.6554 -42.1106 3388
2011 JR20110319 (JR252, JR254C) 2013 JR20130317 (JR272B, JR273A, JR281, UKD-4) -60.6384 -42.1727 3094
2013 JR20130317 (JR272B, JR273A, JR281, UKD-4) 2015 JR20150309 (JR272D, JR310) -60.6365 -42.1786 3023
2015 JR20150309 (JR272D, JR310)     -60.6362 -42.1786 3036

Detailed information for each deployment can be accessed from the OP2 Data Activity document.

Other Series linked to this Fixed Station for this cruise - 1223416 1223428 1362778 1362791

Other Cruises linked to this Fixed Station (with the number of series) - ES033a (7) ES20070116 (ES031, ES038, ES048) (7)

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