Metadata Report for BODC Series Reference Number 745978


Metadata Summary

Data Description

Data Category Hydrography time series at depth
Instrument Type
NameCategories
RBR XR-420 CTD Marine  water temperature sensor; salinity sensor
Instrument Mounting subsurface mooring
Originating Country United Kingdom
Originator Dr Stuart Cunningham
Originating Organization National Oceanography Centre, Southampton
Processing Status banked
Project(s) Rapid Climate Change Programme
RAPIDMOC
 

Data Identifiers

Originator's Identifier 5EB2/9656
BODC Series Reference 745978
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2006-06-01 13:30
End Time (yyyy-mm-dd hh:mm) 2006-12-02 12:00
Nominal Cycle Interval 600.0 seconds
 

Spatial Co-ordinates

Latitude 23.89750 N ( 23° 53.8' N )
Longitude 24.04633 W ( 24° 2.8' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth 4505.0 m
Maximum Sensor Depth 4505.0 m
Minimum Sensor Height 587.0 m
Maximum Sensor Height 587.0 m
Sea Floor Depth 5092.0 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 Approximate - Depth is only approximate
 

Parameters

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
PREXISPS 1 Decibars Pres Pressure (measured variable) exerted by the water body by semi-fixed in-situ pressure sensor
TEMPPR01 1 Degrees Celsius Temp Temperature of the water body
 

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

RAPIDMOC Data Quality Report

The pressure data includes that exerted by the atmosphere.


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

RBR XR-420 CTD

The XR-420 CTD Marine is a small, autonomous conductivity, temperature and depth recorder, from which high accuracy speed of sound and salinity can be derived. Its titanium housing provides a depth rating for the cell of 6,600m which can be axial to the logger, whilst also providing shielding and stable cell geometry. The normal marine conductivity range of 0 to 70 mS/cm is measured by an inductive cell to an accuracy of ±0.003 mS/cm and with a response time of less than 95 milliseconds when profiling. It uses a three-coil system with a closed loop feedback for superior temperature compensation. 8MB of nonvolatile flash memory allows for 2, 400, 000 readings which can be logged on one set of high-powered 3V lithium batteries

Specifications

  Temperature (°C) Conductivity (S/m) Optional Pressure
Measurement Range -5 to +35 0 to 7 (0 to 70 mS/cm) 0 to full scale range: 10/25/60/150/250/740/1000/2000/ 3000/4000/6600 metres (dBar)
Accuracy ± 0.002 °C ± 0.003 mS/cm ± 0.05% full scale
Resolution <0.00005 °C <0.0001 mS/cm <0.001% full scale
Communications RS-232/485; logged, cable, or telemetry
Download Speed ~115,000 samples/minute
Memory 8Mbyte nonvolatile flash (2,400,000 samples)
Sample Rate 1Hz* to 24 hours (programmable)
Clock Accuracy ± 32 seconds/year
Power QTY 4, 3V CR123A cells.
Housing Depth rating of the cell of up to 6,600m
Size 400mm x 64mm
Weight of plastic (without pressure) In water: 0.389Kg
In air: 1.259Kg
Calibration NIST traceable standards

Further information can be found on the Official RBR Website or in the manufacturer's specification sheet .

RAPIDMOC Calibration Coefficients: Series 745978

BODC Series identifier 745978
Instrument Serial number 9656
Deployment cruise RRS Discovery cruise D304
Recovery cruise FS Poseidon cruise PO345

Processing Log

Variable pre-cruise post-cruise
Conductivity [mS/cm] NaN NaN
Temperature [°C] NaN NaN
Pressure [dbar] NaN NaN


No CTD dip calibration data available.
Pressure drift removal? n
Conductivity pressure correction redone? n
Skipped conductivity intervals: [0 200]
Skipped temperature intervals : [0]
Skipped pressure intervals : [0]
Number of additional C points skipped interactively: [0]
Number of additional C points skipped automatically: [0]

RAPIDMOC RBR data processing document

This document outlines the procedures undertaken to process and quality assure the RBR data collected under the RAPIDMOC project.

The raw data are downloaded from the instrument and converted to ASCII format. All processing is performed in Matlab.

Parameter identifiers

The originators use the following parameter identifiers in their output file:

Indentifier Definition
P Pressure
T Temperature (IPTS-90)
C Conductivity (mS/cm)

Calculating calibration coefficients

Prior to deployment and on recovery, a CTD dip is performed with the RBRs strapped onto the CTD frame. This allows calibration of the RBR data by comparing the RBR data with the CTD data. As the RBRs adjustment is much slower than the CTD, data are only compared during bottle stops and after the sensors have adjusted. Bottle stops on these calibration dips last no less than 5 minutes.

Any discrepancy between the RBR clock and the CTD clock is calculated and corrected if necessary.

An average offset (RBR - CTD) is calculated for temperature, conductivity and pressure during the stable period of each bottle stop and interpolated onto the instrument deployment depths. For temperature and conductivity, an average of the offsets derived during the bottle stops is calculated for a specified pressure range where the data are stable (deep water). For pressure, the average offset interpolated to the deployment depth is used. If the calibration dip is shallower than the deployment depth, the offset is extrapolated to the deployment depth.

All the offsets are visually checked and adjusted if necessary.

Applying calibrations

The data are calibrated using the pre and post deployment calibration coefficients. The calibration can be applied as either

If required, a conductivity pressure correction can be applied. This is used if the pressure channel shows spurious data in a particular time interval. A drift in the pressure data can also be removed.

To aid the quality of the calibration, data from CTD casts performed on cruise D279 are used as a reference and are visually compared with the RBR data.

Quality control

All variables in specified time intervals can be set to dummy values if the data are suspicious. Interactive despiking is carried out on the temperature and conductivity data by selecting data based on a T-S plot. Automatic despiking can also be performed using the option to exclude data outside the 6sigma area.

The last stage of the processing is to grid the data onto a pressure field and visually check against historical data. This enables the calibrations to be checked and adjusted if necessary.

RAPIDMOC BODC Data Processing

This document outlines the procedures that take place at BODC for banking RAPIDMOC mooring data.

Data are received after quality checks have been made and calibrations have been applied. The data files are submitted in ASCII format as one file per instrument, with the exception of ADCP data which are submitted as one file per bin.

Once the submitted data files are safely archived, the data undergo standard reformatting and banking procedures:


Project Information

Rapid Climate Change (RAPID) Programme

Rapid Climate Change (RAPID) is a £20 million, six-year (2001-2007) programme of the Natural Environment Research Council (NERC). The programme aims to improve our ability to quantify the probability and magnitude of future rapid change in climate, with a main (but not exclusive) focus on the role of the Atlantic Ocean's Thermohaline Circulation.

Scientific Objectives

Projects

Overall 38 projects have been funded by the RAPID programme. These include 4 which focus on Monitoring the Meridional Overturning Circulation (MOC), and 5 international projects jointly funded by the Netherlands Organisation for Scientific Research, the Research Council of Norway and NERC.

The RAPID effort to design a system to continuously monitor the strength and structure of the North Atlantic Meridional Overturning Circulation is being matched by comparative funding from the US National Science Foundation (NSF) for collaborative projects reviewed jointly with the NERC proposals. Three projects were funded by NSF.

A proportion of RAPID funding as been made available for Small and Medium Sized Enterprises (SMEs) as part of NERC's Small Business Research Initiative (SBRI). The SBRI aims to stimulate innovation in the economy by encouraging more high-tech small firms to start up or to develop new research capacities. As a result 4 projects have been funded.


Monitoring the Meridional Overturning Circulation at 26.5N (RAPIDMOC)

Scientific Rationale

There is a northward transport of heat throughout the Atlantic, reaching a maximum of 1.3PW (25% of the global heat flux) around 24.5°N. The heat transport is a balance of the northward flux of a warm Gulf Stream, and a southward flux of cooler thermocline and cold North Atlantic Deep Water that is known as the meridional overturning circulation (MOC). As a consequence of the MOC northwest Europe enjoys a mild climate for its latitude: however abrupt rearrangement of the Atlantic Circulation has been shown in climate models and in palaeoclimate records to be responsible for a cooling of European climate of between 5-10°C. A principal objective of the RAPID programme is the development of a pre-operational prototype system that will continuously observe the strength and structure of the MOC. An initiative has been formed to fulfill this objective and consists of three interlinked projects:

The entire monitoring array system created by the three projects will be recovered and redeployed annually until 2008 under RAPID funding. From 2008 until 2014 the array will continue to be serviced annually under RAPID-WATCH funding.

The array will be focussed on three regions, the Eastern Boundary (EB), the Mid Atlantic Ridge (MAR) and the Western Boundary (WB). The geographical extent of these regions are as follows:

References

Baehr, J., Hirschi, J., Beismann, J.O. and Marotzke, J. (2004) Monitoring the meridional overturning circulation in the North Atlantic: A model-based array design study. Journal of Marine Research, Volume 62, No 3, pp 283-312.

Baringer, M.O'N. and Larsen, J.C. (2001) Sixteen years of Florida Current transport at 27N Geophysical Research Letters, Volume 28, No 16, pp3179-3182

Bryden, H.L., Johns, W.E. and Saunders, P.M. (2005) Deep Western Boundary Current East of Abaco: Mean structure and transport. Journal of Marine Research, Volume 63, No 1, pp 35-57.

Hirschi, J., Baehr, J., Marotzke J., Stark J., Cunningham S.A. and Beismann J.O. (2003) A monitoring design for the Atlantic meridional overturning circulation. Geophysical Research Letters, Volume 30, No 7, article number 1413 (DOI 10.1029/2002GL016776)


Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2006-06-01
End Date (yyyy-mm-dd) 2006-12-02
Organization Undertaking ActivityNational Oceanography Centre, Southampton
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierEB2#5
Platform Categorysubsurface mooring

RAPID Moored Instrument Rig EB2#5

This rig was deployed as part of the Eastern Boundary (EB) array of the RAPIDMOC project.

Deployment cruise RRS Discovery cruise D304
Recovery cruise FS Poseidon cruise PO345

The rig was anchored by 1600kg of chain and was kept erect by a 48" steel sub-surface float supplemented by groups of smaller buoyancy attached along the mooring.

Instruments deployed on the rig

Depth Instrument
126m Sea-Bird SBE37 IMP MicroCAT (#4465)
127m-2662m McLane Moored Profiler (#11794-01)
2663m Sea-Bird SBE37 IMP MicroCAT (#4471)
2957m Sea-Bird SBE37 IMP MicroCAT (#3283)
3463m Sea-Bird SBE37 IMP MicroCAT (#4467)
3966m Sea-Bird SBE37 IMP MicroCAT (#4460)
4495m Sea-Bird SBE37 IMP MicroCAT (#3281)
4505m RBR XR420 CTD (#9656)
5060m Sea-Bird SBE37 IMP MicroCAT (#4463)

Other Series linked to this Data Activity - 745801 745837 745849 745813 745850 745794 745825

Cruise

Cruise Name D304
Departure Date 2006-05-12
Arrival Date 2006-06-06
Principal Scientist(s)Torsten Kanzow (National Oceanography Centre, Southampton)
Ship RRS Discovery

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameEastern Boundary Array
CategoryOffshore area
Latitude25° 51.60' N
Longitude18° 43.98' W
Water depth below MSL

RAPIDMOC Eastern Boundary (EB) Array

The Eastern Boundary Array defines a box in which moorings are deployed at the eastern side of the North Atlantic as part of the RAPIDMOC project. The box region has latitudinal limits of 23.5° N to 29° N and longitudinal limits of 12° W to 25.5° W. Moorings have occupied this region since 2004 and are typically deployed for 6 to 18 months.

Moored data summary

A description of the data types can be found at the bottom of this document.

Year Cruise ID Number of moorings Data types (number of instruments)
2004 D277, PO319 11 BPR (7), CM (10), MCTD (32)
2005 CD170,CD177 15 ADCP (1), BPR (4), CM (4), MCTD (71), IES (2), MMP (1)
2006 D304, PO343, PO345 24 BPR (6), CM (4), MCTD (78), MMP (1)
2007 D324 13 BPR (3), MCTD (53), IES (2)
2008 D334 14 BPR (3), CM (2), MCTD (44), IES (1)
2009 D344 14 BPR (4), CM (2), MCTD (44)
2011 D359, JC064 22 BPR (12), CM (18), MCTD (80), IES (1)
2012 D382 9 BPR (6), CM (10), MCTD (50)
2014 JC103 9 BPR (6), CM (10), MCTD (50)
2015 DY039 9 BPR (6), CM (9), MCTD (50), MCTDO (5), pCO2 (1), RAS (1), SeapHOx (1)

Cruise data summary

During the cruises to service the moored array, a variety of data types are collected. The table below is a summary of these data. The number of CTD profiles performed on these cruises within the box region defined above is also included. Trans-Atlantic hydrographic CTD sections have also been performed since 2004 and are included in the table.

Cruise ID Cruise description Data types Number of CTD profiles performed within the box region
D277 Initial array deployment MET, NAV, SADCP, SURF -
D279 Hydrographic section CTD, DIS, LADCP, MET, NAV, SADCP, SURF 21
CD170 Array service BATH, CTD, DIS, MET, NAV, SADCP, SURF 4
CD177 Array service BATH, CTD, DIS, MET, NAV, SADCP, SURF 6
D304 Array service CTD, DIS, MET, NAV, SADCP, SURF 8
PO343 Array service CTD, DIS, MET, NAV, SADCP, SURF 5
PO345 Array service CTD, DIS, MET, NAV, SADCP, SURF 4
D324 Array service CTD, DIS, MET, NAV, SADCP, SURF 5
D334 Array service CTD, DIS, MET, NAV, SADCP, SURF 15
D344 Array service CTD, DIS, MET, NAV, SADCP, SURF 5
D346 Hydrographic section CTD, DIS, LADCP, MET, NAV, SADCP, SURF 22
D359 Array service CTD, DIS, MET, NAV, SADCP, SURF 4
JC064 Array service CTD, DIS, MET, NAV, SADCP, SURF 5
D382 Array service CTD, DIS, MET, NAV, SADCP, SURF 5
JC103 Array service CTD, DIS, MET, NAV, SADCP, SURF 11
DY039 Array service CTD, DIS, MET, NAV, SADCP, SURF 6

Data type ID and description

Data type ID Description
ADCP Acoustic Doppler Current Profiler
BATH Bathymetry
BPR Bottom Pressure Recorder
CM Current Meter
CTD Conductivity-Temperature-Depth profiler
DIS Discrete water bottle samples
IES Inverted Echo Sounder
LADCP Lowered Acoustic Doppler Current Profiler
MET Meteorology
MCTD Moored Conductivity-Temperature-Depth sensor
MCTDO Moored Conductivity-Temperature-Depth-Oxygen sensor
MMP McLane Moored Profiler - profiling CTD and current meter
NAV Navigation
pCO2 Moored pCO2 sensor
RAS Remote Access Sampler
SADCP Shipborne Acoustic Doppler Current Profiler
SeapHOx Moored pH-Conductivity-Temperature-Depth-Oxygen sensor
SURF Sea surface data

Other Series linked to this Fixed Station for this cruise - 745524 745536 745548 745561 745573 745585 745597 745604 745616 745628 745641 745653 745665 745677 745689 745690 745708 745721 745733 745745 745757 745769 745770 745782 745794 745801 745813 745825 745837 745849 745850 745862 745874 745886 745898 745905 745917 745929 745930 745942 745954 745966 745991 770275 770287 770299 770306 770318 770331 770343 770355 770367 770379 770380 946148 946185

Other Cruises linked to this Fixed Station (with the number of series) - CD170 (52) CD177 (31) D277 (39) D324 (61) D334 (44) D344 (48) D346 (22) D359 (49) D382 (59) JC064 (54) JC103 (11) PO343 (10) PO345 (30)


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