Metadata Report for BODC Series Reference Number 700068


Metadata Summary

Data Description

Data Category Hydrography time series at depth
Instrument Type
NameCategories
Sea-Bird SBE 37-SMP MicroCAT C-T Sensor  water temperature sensor; salinity sensor
Instrument Mounting subsurface mooring
Originating Country United Kingdom
Originator Dr Stuart Cunningham
Originating Organization Southampton Oceanography Centre (now National Oceanography Centre, Southampton)
Processing Status banked
Project(s) Rapid Climate Change Programme
RAPIDMOC
 

Data Identifiers

Originator's Identifier 2MAR1/3272
BODC Series Reference 700068
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2005-04-23 19:15
End Time (yyyy-mm-dd hh:mm) 2006-05-24 14:00
Nominal Cycle Interval 900.0 seconds
 

Spatial Co-ordinates

Latitude 25.62583 N ( 25° 37.5' N )
Longitude 50.41867 W ( 50° 25.1' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth 2097.0 m
Maximum Sensor Depth 2097.0 m
Minimum Sensor Height 2773.0 m
Maximum Sensor Height 2773.0 m
Sea Floor Depth 4870.0 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
CNDCPR01 1 Siemens per metre InSituCond Electrical conductivity of the water body by in-situ conductivity cell
PREXMCAT 1 Decibars Pres_MCat Pressure (measured variable) exerted by the water body by semi-fixed moored SBE MicroCAT
PSALPR01 1 Dimensionless P_sal Practical salinity of the water body by conductivity cell and computation using UNESCO 1983 algorithm
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


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

Sea-Bird SBE 37-SMP MicroCAT

The SBE 37-SMP MicroCAT is a high accuracy conductivity and temperature recorder (pressure optional) with Serial interface, internal battery, non-volatile FLASH Memory and integral Pump. The Integral Pump runs for 1 second each time the MicroCAT samples, improving the conductivity response and giving improved anti-foul protection.

Designed for moorings and other long-duration, fixed-site deployments, MicroCATs have non-corroding titanium housings rated for operation to 7000 meters or pressure sensor full scale-range. Communication with the MicroCAT is over an internal, 3-wire, RS-232C link. The MicroCAT's aged and pressure-protected thermistor has a long history of exceptional accuracy and stability (typical drift is less than 0.002°C per year). Electrical isolation of the conductivity electronics eliminates any possibility of ground-loop noise.

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: 20 / 100 / 350 / 600 / 1000 / 2000 / 3500 / 7000 metres
Initial accuracy 0.002 0.0003 0.1% of full scale range
Typical Stability 0.0002 per month 0.0003 per month 0.05% of full scale range per year
Resolution 0.0001 0.00001 0.002% of full scale range
Data Storage Temperature and conductivity: 6 bytes per sample
Time: 4 bytes per sample
Pressure (optional): 5 bytes per sample
Clock stability 5 seconds per month
Standard Internal Batteries Nominal 10.6 Ampere-hour pack consisting of twelve AA lithium batteries. Provides sufficient capacity for more than 100,000 samples for a typical sampling scheme
Housing Titanium pressure case rated at 7000 metres
Weight (without pressure) In water: 3kg
In air: 5kg

Further information can be found via the following link: Sea-Bird SBE 37-SMP MicroCAT Datasheet

RAPIDMOC Calibration Coefficients: Series 700068

BODC Series identifier 700068
Instrument Serial number 3272
Deployment cruise CD170
Recovery cruise D304

Processing Log

Variable pre-cruise post-cruise
Conductivity [mS/cm] NaN -0.0042
Temperature [°C] NaN -0.0001
Pressure [dbar] NaN -0.7000

Post cruise coefficients were applied as constant offsets.
Pressure drift removal? n
Conductivity pressure correction redone? n
Skipped conductivity intervals: [0]
Skipped temperature intervals : [0]
Skipped pressure intervals : [0]
Number of additional C points skipped interactively: [4]
Number of additional C points skipped automatically: [21]

RAPIDMOC/MOCHA Sea-Bird MicroCAT data processing document

This document outlines the procedures undertaken to process and quality assure the MicroCAT data collected under the RAPIDMOC and MOCHA projects.

Originator's processing

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

Calculating calibration coefficients

Prior to deployment and on recovery, a CTD dip is performed with the MicroCATs strapped onto the CTD frame. This allows calibration of the MicroCAT data by comparing the MicroCAT data with the CTD data. As the MicroCATs 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 MicroCAT clock and the CTD clock is calculated and corrected if necessary.

An average offset (MicroCAT - 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 near mooring locations on previous cruises are used as a reference and are visually compared with the MicroCAT data.

Quality control

All variables in specified time intervals can be set to dummy values if the data are suspect and it is also possible to apply an offset to a subsection of a particular channel, if required. Interactive despiking can be carried out on the temperature and conductivity data, if present, by selecting data based on a T-S plot. Automatic despiking can also be performed using the option to exclude data outside the 6σ 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. On occasion, comparison of the time series with historical data and series from nearby instruments highlights the need for removal of a drift from one or more data channels. This is accomplished by removing a linear trend from the appropriate channel(s) and may affect the entire series or a subsection thereof. If a trend has been removed it will be noted in the 'RAPIDMOC Calibration Coefficients' section of the documentation.

BODC processing

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.

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

Parameter mapping

The following describes the parameters contained in the originator's files and their mapping to BODC parameter codes:

Identifier Unit Definition BODC parameter code Units Unit conversion Comments
YY year Year AADYAA01 days - Combined with MM and DD to form a date and transferred
MM month Month AADYAA01 days - Combined with MM and DD to form a date and transferred
DD day Day AADYAA01 days - Combined with MM and DD to form a date and transferred
HH hour Decimal hours AAFDZZ01 days /24 Transferred
P decibar Pressure PREXMCAT decibars - Transferred
T °C Temperature (IPTS-90) TEMPPR01 °C - Transferred
C mS/cm Conductivity CNDCPR01 S/m /10 Transferred

Parameter derivation

The following describes the parameters derived by BODC and their mapping to BODC parameter codes:

BODC parameter code Units Variables Definition Units Equation Comments
PSALPR01 dimensionless PREXMCAT
TEMPPR01
CNDCPR01
Pressure
Temperature
Conductivity
decibars
°C
S/m
UNESCO 1983 polynomial for salinity -

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) 2005-04-23
End Date (yyyy-mm-dd) 2006-05-24
Organization Undertaking ActivitySouthampton Oceanography Centre (now National Oceanography Centre, Southampton)
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierMAR1#2
Platform Categorysubsurface mooring

RAPID Moored Instrument Rig MAR1#2

This rig was deployed as part of the Mid Atlantic Ridge (MAR) array of the RAPIDMOC project .

Deployment cruise RRS Charles Darwin cruise CD170
Recovery cruise RRS Discovery cruise D304

The instruments were anchored by 1360kg of chain and kept erect by 17" diameter buoyancy spheres attached at a range of depths. A Billings 4 marker float with Novatech light was attached to the top of the mooring.

Instruments deployed on the rig

Depth Instrument
140m Sea-Bird SBE37 SMP MicroCAT (#3224)
185m Sea-Bird SBE37 SMP MicroCAT (#3234)
335m Sea-Bird SBE37 SMP MicroCAT (#3225)
695m Sea-Bird SBE37 SMP MicroCAT (#3266)
1101m Sea-Bird SBE37 SMP MicroCAT (#3265)
1695m Sea-Bird SBE37 SMP MicroCAT (#3268)
2097m Sea-Bird SBE37 SMP MicroCAT (#3272)
2606m Sea-Bird SBE37 SMP MicroCAT (#3269)
3114m Sea-Bird SBE37 SMP MicroCAT (#3483)
3624m Sea-Bird SBE37 SMP MicroCAT (#3484)
4127m Sea-Bird SBE37 SMP MicroCAT (#3486)
4760m InterOcean S4AD current meter (#35612566)
4860m InterOcean S4AD current meter (#35612576)

Other Series linked to this Data Activity - 700019 700044 700056 700112 700007 700020 700093 700100 700032 700081

Cruise

Cruise Name CD170
Departure Date 2005-04-02
Arrival Date 2005-04-27
Principal Scientist(s)Stuart A Cunningham (Southampton Oceanography Centre)
Ship RRS Charles Darwin

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameMid-Atlantic Ridge Array
CategoryOffshore area
Latitude24° 45.00' N
Longitude45° 30.00' W
Water depth below MSL

RAPIDMOC Mid-Atlantic Ridge (MAR) Array

The Mid-Atlantic Ridge Array defines a box in which moorings are deployed either side of the Mid-Atlantic Ridge in the North Atlantic as part of the RAPIDMOC project. The box region has latitudinal limits of 23° N to 26.5° N and longitudinal limits of 40° W to 52.1° W. Moorings have occupied this region since 2004 and are typically deployed for 12 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 4 BPR (4), CM (5), MCTD (20), MMP (1)
2005 CD170 6 BPR (4), CM (6), MCTD (24)
2006 D304 5 BPR (3), CM (3), MCTD (32)
2007 D324 6 BPR (4), CM (3), MCTD (33)
2008 D334 6 BPR (4), CM (3), MCTD (39)
2009 D344 6 BPR (6), CM (3), MCTD (40)
2010 D359 6 BPR (6), CM (5), MCTD (40)
2011 JC064 6 BPR (6), CM (5), MCTD (40)
2012 D382 6 BPR (6), CM (5), MCTD (34)
2014 JC103 6 BPR (6), CM (1), MCTD (34)

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 DIS, MET, NAV, SADCP, SURF -
D279 Hydrographic section CTD, DIS, LADCP, MET, NAV, SADCP, SURF 19
CD170 Array service CTD, DIS, MET, NAV, SADCP, SURF 5
D304 Array service CTD, DIS, MET, NAV, SADCP, SURF 1
D324 Array service CTD, DIS, MET, NAV, SADCP, SURF 3
D334 Array service CTD, DIS, MET, NAV, SADCP, SURF 5
D344 Array service CTD, DIS, MET, NAV, SADCP, SURF 5
D346 Hydrographic section CTD, DIS, LADCP, MET, NAV, SADCP, SURF 21
D359 Array service CTD, DIS, MET, NAV, SADCP, SURF 5
JC064 Array service CTD, DIS, MET, NAV, SADCP, SURF 6
D382 Array service CTD, DIS, MET, NAV, SADCP, SURF 3
JC103 Array service CTD, DIS, MET, NAV, SADCP, SURF 4

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
MMP McLane Moored Profiler - profiling CTD and current meter
NAV Navigation
SADCP Shipborne Acoustic Doppler Current Profiler
SURF Sea surface data

Other Series linked to this Fixed Station for this cruise - 700007 700019 700020 700032 700044 700056 700081 700093 700100 700112 700124 700136 700148 700161 700173 700185 700197 700204 700216 700228 700241 700253 701545 945981 945993 946020 946032 1066414 1066426 1066438 1066451 1066463

Other Cruises linked to this Fixed Station (with the number of series) - D277 (24) D304 (31) D324 (40) D334 (32) D344 (42) D346 (21) D359 (49) D382 (35) JC064 (45) JC103 (4)


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