Metadata Report for BODC Series Reference Number 813049


Metadata Summary

Data Description

Data Category Hydrography time series at depth
Instrument Type
NameCategories
Sea-Bird SBE 37-IM MicroCAT C-T Sensor  water temperature sensor; salinity sensor
Instrument Mounting subsurface mooring
Originating Country United States
Originator Prof Bill Johns
Originating Organization Rosenstiel School of Marine and Atmospheric Science
Processing Status banked
Project(s) MOCHA
 

Data Identifiers

Originator's Identifier M368/3866
BODC Series Reference 813049
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2005-05-17 21:30
End Time (yyyy-mm-dd hh:mm) 2006-10-02 11:30
Nominal Cycle Interval 1800.0 seconds
 

Spatial Co-ordinates

Latitude 26.50167 N ( 26° 30.1' N )
Longitude 71.97133 W ( 71° 58.3' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor Depth 252.0 m
Maximum Sensor Depth 252.0 m
Minimum Sensor Height 5046.0 m
Maximum Sensor Height 5046.0 m
Sea Floor Depth 5298.0 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 SBE37-IM MicroCAT

The SBE 37-IM MicroCAT is a high accuracy conductivity and temperature recorder (pressure optional) with a built in Inductive Modem, which provides reliable, low-cost, real-time data transmission. Designed for moorings and other long-duration, fixed-site deployments, MicroCATs have non-corroding titanium housings rated for operation to 7000 metres or pressure sensor full scale-range.

Communication with the MicroCAT is via a Surface Inductive Modem (SIM) to a computer or data logger. Commands and data are transmitted half-duplex between the SIM and the MicroCAT using DPSK (differential-phase-shift-keyed) telemetry. As a safe guard, the MicroCAT simultaneously backs up the data in its non-volatile internal memory as well as transmitting the data via telemetry.

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 -1 ) Optional Pressure
Measurement Range -5 to +35 0 to 7 (0 to 70 mS cm -1 ) 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
Sensor Calibration +1 to +32 0 to 6; physical calibration over range 2.6 to 6 S m -1 , plus zero conductivity (air) Ambient pressure to full scale range in 5 steps
Memory 8 Mbyte non-volatile FLASH memory
Data Storage Converted temperature and conductivity: 5 bytes per sample (2.5 bytes each)
Time: 4 bytes per sample
Pressure (optional): 2 bytes per sample
Real-Time Clock 32,768 Hz TCXO accurate to ±1 minutes year -1
Standard Internal Batteries 10.6 Ampere-hour pack consisting of 12 AA lithium batteries. Provides sufficient capacity for more than 200,000 samples for a typical sampling scheme
Housing Titanium pressure case rated at 7000 metres
Weight (without pressure) In water: 2.4 kg
In air: 4.0 kg

Further information can be found via the following link: Sea-Bird SBE37-IM MicroCAT Datasheet

RAPIDMOC Calibration Coefficients: Series 813049

BODC Series identifier 813049
Instrument Serial number 3866
Deployment Cruise RV Knorr (KN182-2)
Recovery Cruise RV Seward Johnson (SJ14-06)

Processing Log

Variable Pre-cruise Post-cruise
Conductivity [mS/cm] -0.0028 -0.0005
Temperature [ o C] -0.0016 -0.0002
Pressure [dbar] -4.3000 0.1000

Pre and post cruise coefficients were averaged and applied as constant offsets to all three channels
Pressure drift removal? n
Conductivity pressure correction redone? n
Skipped conductivity intervals: [32.78 36.41 71.09 71.999 77.63 80.352 154.022 159.896 336.9 348.4375 375.793 376.354 423.668 469.1 476.23 477.43]
Skipped temperature intervals : [0]
Skipped pressure intervals : [0]
Number of additional C points skipped interactively: [1040]
Number of additional C points skipped automatically: [0]

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

Meridional Overturning Circulation and Heatflux Array (MOCHA) Project

Introduction

Users of these data are referred to the Meridional Overturning Circulation and Heatflux Array (MOCHA) Project Website for more information. The following text has been taken from the website.

Scientific Rationale

To set in place a system for continuous observation of the meridional heat transport in the subtropical Atlantic, with which to document its variability and its relationship to oberved climate fluctuations, and to assess climate model predictions

Overview

MOCHA is a collaborative project, partnered with the UK RAPID Program, to measure the heat and freshwater transports of the North Atlantic Ocean. These transports are called the Thermohaline or Overturning Circulation. Simply put, warm waters move poleward at the surface of the ocean, where they cool and sink, to return equatorward in the deep ocean.


Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2005-05-17
End Date (yyyy-mm-dd) 2006-10-02
Organization Undertaking ActivityRosenstiel School of Marine and Atmospheric Science
Country of OrganizationUnited States
Originator's Data Activity IdentifierWB5#2
Platform Categorysubsurface mooring

RAPID Moored Instrument Rig WB5#2

This rig was deployed as part of the Western Boundary (WB) array of the MOCHA/RAPIDMOC project.

Instruments deployed on the rig

Deployment cruise RV Knorr cruise KN182_2
Recovery cruise RV Seward Johnson cruise SJ14-06

The rig was anchored by approximately 2404kg of weight and was kept erect by a large sub-surface float supplemented by groups of smaller buoyancy all attached on titanium swivels. A telemetry buoy was attached to the top of the mooring to sit on the surface and transmit near real time data.

Instruments deployed on the rig

Depth Instrument
49m Sea-Bird SBE37 IMP MicroCAT (#3867)
103m Sea-Bird SBE37 IMP MicroCAT (#3868)
252m Sea-Bird SBE37 IMP MicroCAT (#3866)
402m Sea-Bird SBE37 IMP MicroCAT (#3870)
603m Sea-Bird SBE37 IMP MicroCAT (#3869)
804m Sea-Bird SBE37 IMP MicroCAT (#3872)
1000m Sea-Bird SBE37 IMP MicroCAT (#3871)
1198m Sea-Bird SBE37 IMP MicroCAT (#3150)
1600m Sea-Bird SBE37 IMP MicroCAT (#3152)
2000m Sea-Bird SBE37 IMP MicroCAT (#3153)
2496m Sea-Bird SBE37 IMP MicroCAT (#3154)
2993m Sea-Bird SBE37 IMP MicroCAT (#3155)
3488m Sea-Bird SBE37 IMP MicroCAT (#3156)
3986m Sea-Bird SBE37 IMP MicroCAT (#3158)
4479m Sea-Bird SBE37 IMP MicroCAT (#3159)
4979m Sea-Bird SBE37 IMP MicroCAT (#3161)

Other Series linked to this Data Activity - 813074 813037 813025 813105 813130 813154 813178 813050 813062 813098 813086 813142 813129 813166 813117

Cruise

Cruise Name KN182_2
Departure Date 2005-05-02
Arrival Date 2005-05-26
Principal Scientist(s)William E Johns (Rosenstiel School of Marine and Atmospheric Science)
Ship RV Knorr

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameWestern Boundary Array
CategoryOffshore area
Latitude26° 37.50' N
Longitude73° 37.50' W
Water depth below MSL

RAPIDMOC/MOCHA Western Boundary (WB) Array

The Western Boundary Array defines a box in which moorings were deployed at the western side of the North Atlantic as part of the RAPIDMOC project and the collaborative project Meridional Overturning Circulation and Heatflux Array (MOCHA). The box region has latitudinal limits of 26° N to 27.5° N and longitudinal limits of 69.5° W to 77.5° W. Moorings have occupied this region since 2004 and are typically deployed for 6 to 18 months.

Moored data summary

Year Cruise ID Number of moorings Data types (number of instruments)
2004 D278 9 (6 RAPIDMOC, 3 MOCHA) ADCP (2), BPR (8), CM (29), MCTD (52), MMP (1)
2005 KN182_2 11 (6 RAPIDMOC, 5 MOCHA) ADCP (2), BPR (6), CM (27), MCTD (56)
2006 RB06-02, SJ14-06 11 (6 RAPIDMOC, 5 MOCHA) ADCP (1), BPR (3), CM (22), IES (7), MCTD (60)
2007 RB07-01 7 (7 RAPIDMOC) ADCP (1), BPR (4), CM (16), MCTD (47)
2008 SJ08-03 11 (8 RAPIDMOC, 3 MOCHA) ADCP (2), BPR (3), CM (40), MCTD (80)
2009 RB0901, D344, D345 16 (11 RAPIDMOC, 5 MOCHA) ADCP (2), BPR (5), CM (39), MCTD (91), DVS (1)
2010 OC459-1, RB1009 9 (8 RAPIDMOC, 1 MOCHA) ADCP (1), BPR (7), CM (23), MCTD (54)
2011 KN200-4 7 (7 RAPIDMOC, 6 MOCHA) ADCP (2), BPR (7), CM (43), MCTD (86), DVS (1), IES (1)
2012 RB1201, EN517, D382 24 (19 RAPIDMOC, 5 MOCHA) ADCP (3), BPR (19), CM (74), MCTD (130), IES(1)
2014 JC103 24 (9 RAPIDMOC) BPR (8), CM (22), MCTD (36)

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 1
D278 Initial array deployment DIS, MET, NAV, SADCP, SURF 16
D279 Hydrographic section CTD, DIS, LADCP, MET, NAV, SADCP, SURF 31
KN182_2 Array service CTD, DIS, MET, NAV, SADCP, SURF 64
RB0601 Array service CTD, DIS, LADCP, MET, NAV, SADCP, SURF 39
SJ14-06 Array service CTD, DIS, LADCP, MET, NAV, SADCP, SURF 33
RB07-01 Array service CTD, DIS, LADCP, MET, NAV, SADCP, SURF 36
SJ08-03 Array service CTD, DIS, LADCP, MET, NAV, SADCP, SURF 33
RB0901 Array service CTD, DIS, LADCP, MET, NAV, SADCP, SURF 35
D344 Array service CTD, DIS, MET, NAV, SADCP, SURF 3
D345 Array service CTD, DIS, LADCP, MET, NAV, SADCP, SURF 24
OC459-1 Array service CTD, DIS, MET, NAV, SADCP, SURF 9
OC459-2 Western Boundary Hydrographic section CTD, DIS, LADCP, MET, NAV, SADCP, SURF 27
D346 Hydrographic section CTD, DIS, LADCP, MET, NAV, SADCP, SURF 31
RB1009 WB4 service CTD, MET, SURF, NAV 2
KN200-4 Array service CTD, DIS, MET, NAV, SURF 34
RB1201 Array service CTD, DIS, MET, NAV, SURF 10
EN517 Array service CTD, DIS, LADCP, MET, NAV, SURF 31
D382 Array service CTD, DIS, MET, NAV, SURF 8
JC103 Array service CTD, DIS, MET, NAV, SURF 7

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
DVS Doppler Volume sampler
IES Inverted Echo Sounder
LADCP Lowered Acoustic Doppler Current Profiler
MET Meteorology
MCTD Moored Conductivity-Temperature-Depth sensor
MOCTD Moored Conductivity-Temperature-Depth Oxygen 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 - 738828 738841 738853 738865 738877 738889 738890 738908 738921 738933 738945 738957 738969 738970 738982 738994 739008 739021 739033 739045 739057 739069 739070 739082 739094 739101 739113 739125 739137 739149 774528 774541 774553 774565 774577 774589 774590 774608 774621 774633 774645 774657 774669 774670 774682 774694 774701 774713 774725 774737 774749 812882 812894 812901 812913 812925 812937 812949 812950 812962 812974 812986 812998 813001 813013 813025 813037 813050 813062 813074 813086 813098 813105 813117 813129 813130 813142 813154 813166 813178 946204 946216 946253 946265 1137318 1137331

Other Cruises linked to this Fixed Station (with the number of series) - D278 (90) D344 (10) D345 (43) D346 (31) D382 (85) EN517 (11) JC103 (9) KN200-4 (135) OC459-1 (64) RB0602 (42) RB0701 (58) RB0901 (78) RB1009 (24) RB1201 (91) SJ-08-03 Leg 1 (39) SJ-08-03 Leg 2 (76) SJ-14-06 (62)


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