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Metadata Report for BODC Series Reference Number 1643329

Metadata Summary

Data Description

Data Category Multiple data types -ship
Instrument Type
Sea-Bird SBE 45 MicroTSG thermosalinograph  thermosalinographs; water temperature sensor; salinity sensor
Pico-Technology PT-100 Temperature Sensor Model SE012  water body temperature sensor
LI-COR LI-840A CO2/H2O gas analyser  atmospheric gas analysers
GE Druck UNIK 5000 Pressure Sensing Platform  water pressure sensors
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Dr Naomi Greenwood
Originating Organization Centre for Environment, Fisheries and Aquaculture Science Lowestoft Laboratory
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) UKOARP_ThemeA

Data Identifiers

Originator's Identifier CEND_20_12_B_DATA_CO2
BODC Series Reference 1643329

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2012-12-03 13:05
End Time (yyyy-mm-dd hh:mm) 2012-12-04 22:28
Nominal Cycle Interval 300.0 seconds

Spatial Co-ordinates

Southernmost Latitude 51.97888 N ( 51° 58.7' N )
Northernmost Latitude 52.88479 N ( 52° 53.1' N )
Westernmost Longitude 1.79287 E ( 1° 47.6' E )
Easternmost Longitude 2.90954 E ( 2° 54.6' E )
Positional Uncertainty Unspecified
Minimum Sensor or Sampling Depth -16.0 m
Maximum Sensor or Sampling Depth 4.0 m
Minimum Sensor or Sampling Height -
Maximum Sensor or Sampling Height -
Sea Floor Depth -
Sea Floor Depth Source -
Sensor or Sampling Distribution Scattered at fixed depths - The sensors are scattered with respect to depth but each remains effectively at the same depth for the duration of the series
Sensor or Sampling Depth Datum Approximate - Depth is only approximate
Sea Floor Depth Datum -


BODC CODERankUnitsTitle
AADYAA011DaysDate (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ011DaysTime (time between 00:00 UT and timestamp)
ACFLPCO21Not applicableData quality flag (pCO2 IOCCP)
ACO2XXXX1MicroatmospheresPartial pressure of carbon dioxide {CO2 CAS 124-38-9} {pCO2} in the atmosphere
ACYCAA011DimensionlessSequence number
ALATZZ011DegreesLatitude north
ALONZZ011DegreesLongitude east
CAPHZZ011MillibarsPressure (measured variable) exerted by the atmosphere
FCO2WTAT1MicroatmospheresFugacity of carbon dioxide (at 100% humidity) {CAS 124-38-9} in the atmosphere
FCO2XXXX1MicroatmospheresFugacity of carbon dioxide (at 100% humidity) {fCO2 CAS 124-38-9} in the water body
PCO2XXXX1MicroatmospheresPartial pressure of carbon dioxide {CO2 CAS 124-38-9} {pCO2} in the water body
PRES00EQ1MillibarsPressure (in measurement loop for equilibrated marine sample)
PSALZZXX1DimensionlessPractical salinity of the water body by computation using UNESCO 1983 algorithm
TEMPEQMN1Degrees CelsiusTemperature of equilibration
TEMPP9011Degrees CelsiusTemperature (ITS-90) of the water body
WMXRZZ011Millimoles per moleMixing ratio (equilibrated marine sample) of water vapour
XCO2DRAT1Micromoles per moleMole fraction in dry air of carbon dioxide {CO2 CAS 124-38-9} {xCO2} in the atmosphere
XCO2WBDY1Micromoles per moleMole fraction in dry air of carbon dioxide {CO2 CAS 124-38-9} {xCO2} for 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

CEFAS Endeavour pCO2 Underway 2012 - Data Quality report

Data were screened post transfer and data that exceeded the minimum and maximum permissable values were flagged accordingly.

Parameters PCO2XXXX, LPRES0EQ, TEMPP901 and PCO2XXXX had some values flagged as 'N' that were considered to be extreme values and beyond the realms of possibility. This occurred at the end of the file for series' 1207281, 1207348, 1207373, 1207416. Series 1207416 had cycles at the the start flagged as did middle cycles of series' 1207404 and 1207441. This coincided with the Hull PRT not being deployed each time. The raw data file can be made available upon request.

A few spikes exist in the data with all significant spikes being flagged as suspect such as extreme drops in salinity.

Parameter WMXRZZ01 cycle number one was flagged for series 1207324 and 1207428 stributed to high values linked to instrument deployment.

Parameter CAPHZZ01 the end cycle numbers were flagged M in series 1207324 and 1207428 for increases or decreases in pressure at the end of the series

Parameter PSALZZXX series 1207300 has 3 M flags applied to cycles 185, 186 and 1739 respectively. Series 1207428 has cycle numbers 141, 716, 1003, 2154 and 2441 had M flags applied. A lot of these were for salinity appearing to recover from a significant trough which had already been flagged L.

Parameter XCO2WBDY had cycle number one flagged M in series 1207293, 1207324, 1207373 and 1207385. In addition to this series 1207300 has cycle number 215 flagged M and series 1207336 had cycle number 335 flagged M.

Originator flags meant that all data for series 1207312 were flagged as suspect 'L'.

Data Access Policy

Public domain 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.

The recommended acknowledgment is

"This study uses data from the data source/organisation/programme, provided by the British Oceanographic Data Centre and funded by the funding body."

Narrative Documents

LI-COR 840 and LI-COR 840A CO2/H2O Gas Analysers

General Information

The LI-840 and 840A CO2/H2O analysers are simple, low maintenance gas analysers designed for continuous monitoring applications. They are absolute, non-dispersive infrared (NDIR) gas analysers based upon a field proven single path, dual wavelength and thermostatically controlled infrared detection system. They can be used in a wide range of environmental conditions.

Key Features

  • Easy integration into monitoring systems.
  • Wide Measurement Range: 0-20,000 ppm (0-2%) for CO2 and 0-60 mmol/mol for H2O (dry air to 36°C dew point).
  • Wide Operating Temperature: -20° to +45°C.
  • Low Power Consumption: Less than 4W after power-up.
  • Low Noise: Less than 1 ppm at 370 ppm for CO2, less than 0.01 mmol/mol at 10 mmol/mol for H2O with 1 second signal averaging.
  • Flow Rate: Maximum of 1 liter/minute.
  • Real-Time, Corrected Readings: On-board sensors measure and correct for changes in cell temperature and pressure.
  • CO2 concentrations are corrected for band-broadening due to water vapor.
  • User-Cleanable Optics: The optical bench can be easily cleaned by the user. This reduces down-time from contamination and eliminates the need for factory recalibration.
  • Estimated 2+ year source life in continuous operation. The source is field-replaceable without factory calibration.



  LI-COR 840 LI-COR 840A
Measurement Range 0 - 3,000 ppm 0 - 20,000 ppm
Accuracy <1.5% of reading <1% of reading
Calibration Drift
Zero Drift(1) <0.15 ppm/°C <0.15 ppm/°C
Span Drift(2) <0.03%/°C <0.03%/°C
Total Drift(3) at 370 ppm <0.4 ppm/°C <0.4 ppm/°C
RMS Noise at 370 ppm with
1 sec signal filtering <1 ppm <1 ppm
Sensitivity to water vapour <0.1 ppm CO2/ppt H2O N/A


  LI-COR 840 LI-COR 840A
Measurement Range 0 - 80 ppt 0 - 60 ppt
Accuracy <1.5% of reading <1.5% of reading
Calibration Drift
Zero Drift(1) < 0.003 ppt/°C <0.003 ppt/°C
Span Drift(2) <0.06%/°C <0.03%/°C
Total Drift(3) at 370 ppm <0.009 ppt/°C <0.009 ppt/°C
RMS Noise at 10 ppt (LI-840) 370 ppm (LI-840A) with
1 sec signal filtering <0.01 ppt <0.07 ppt
Sensitivity to CO2 <0.0001 ppt <0.0001 ppt H2O/ppm CO2

(1)Zero Drift is the change with temperature at 0 concentration.

(2)Span Drift is the residual error after re-zeroing following a temperature change.

(3)Total Drift is the change with temperature without re-zeroing or re-spanning.

Other Specifications

  LI-COR840 LI-COR840A
Measurement Principle Non-Dispersive Infrared
Traceability Traceable gases to WMO standards for CO2. NIST traceable LI-610 Portable Dew Point Generator for H2O. Traceable gases to WMO standards from 0 to 3,000 ppm. Traceable gases to EPA protocol gases from 3,000 to 20,000 ppm
Pressure Compensation Range 15 kPa - 115 kPa
Maximum Gas Flow Rate 1 liter/min
Output Signals Two Analog Voltage (0-2.5V or 0-5V) and Two Current (4-20mA) Digital: TTL (0-5V) or Open Collector
DAC Resolution 14-bits across user-specified range
Source Life 18,000 Hours (~2 years continuous use)
Power Requirements Input Voltage 12-30 VDC; 1.2A @ 12V (14W) maximum during warmup with heaters on; 0.3A @ 12V (3.6W) average after warmup with heaters on
Operating Temperature Range -20 to 45°C
Relative Humidity Range 0 to 95% RH, Non-Condensing
Dimensions 8.75" x 6" x 3" (22.23 x 15.25 x 7.62 cm)
Weight 2.2 lbs. (1 kg)

More information may be found in the LI-840 manufacturer's manual or the LI-840A manufacturer's brochure.

CEFAS Endeavour pCO2 Underway 2012 - Instrumentation

Instrumentation Used

The followiung table shows the instrumentation used during each of the pCO2 cruises in 2012.

Instrument Serial Number Parameter Measured
Li-COR 840A N/A pCO2
Picotech PT100 SE012 N/A Temperature of equilibration
PT100* N/A Hull Temperature Sensor
GE/Druck UNIK 5000 N/A Atmospheric and equilibrator pressure
Seabird SBE45** N/A Salinity

* N.B. This sensor does no have a Manufacturer name as it cannot be confirmed by CEFAS.

** N.B. Discrete samples collected and analysed using autsalinometer (Guildline) calibrated using standard seawater. Offset for SBE45 from results of discrete samples.

SeaBird MicroTSG Thermosalinograph SBE 45

The SBE45 MicroTSG is an externally powered instrument designed for shipboard measurement of temperature and conductivity of pumped near-surface water samples. The instrument can also compute salinity and sound velocity internally.

The MicroTSG comprises a platinum-electrode glass conductivity cell and a stable, pressure-protected thermistor temperature sensor. It also contains an RS-232 port for appending the output of a remote temperature sensor, allowing for direct measurement of sea surface temperature.

The instrument can operate in Polled, Autonomous and Serial Line Sync sampling modes:

  • Polled sampling: the instrument takes one sample on command
  • Autonomous sampling: the instrument samples at preprogrammed intervals and does not enter quiescence (sleep) state between samples
  • Serial Line Sync: a pulse on the serial line causes the instrument to wake up, sample and re-enter quiescent state automatically


  Conductivity Temperature Salinity
Range 0 to 7 Sm-1 -5 to 35°C  
Initial accuracy 0.0003 Sm-1 0.002°C 0.005 (typical)
Resolution 0.00001 Sm-1 0.0001°C 0.0002 (typical)
Typical stability (per month) 0.0003 Sm-1 0.0002°C 0.003 (typical)

Further details can be found in the manufacturer's specification sheet.

CEFAS Endeavour pCO2 Underway 2012 - Processing Document

Originator's Processing

Measurements and Methods

The data originate from the autonmous underway system on the CEFAS Endeavour taken from 18/02/2012 to 04/12/2012. The underway system consists of a combined glass-bead and showerhead equilibrator. Seawater is supplied by the non-toxic seawater supply and marine air from forward on the vessel. The air streams are dried and measured using a non-dispersive infrared analyser. Data from the equilibrator were calibrated against three standard known gas concentrations. Other measurements taken include pressure, temperature and salinity.


The data were processed and analysed by CEFAS. Data were put through quality control applied by CEFAS and submitted using the WOCE flagging system with additional sub-flags.


Data were submitted as 15 Excel cruise files containing data and metadata. These were accompanied by additional .xml files containing more detailed metadata.


Hardman-Mountford, N. J., Moore, G., Bakker, D. C. E., Watson, A. J., Schuster, U., Barciela, R., Hines, A., Moncoiffé, G., Brown, J., Dye, S., Blackford, J., Somerfield, P. J., Holt, J., Hydes, D. J., and Aiken, J. 2008. An operational monitoring system to provide indicators of CO2-related variables in the ocean. ICES Journal of Marine Science, 65, 1498 - 1503

Kitidis, V., Hardman-Mountford, N. J., Litt, E., Brown, I., Cummings, D., Hartman, S., Hydes, D., Fishwick, J. R., Harris, C., Martinez-Vicente, V., Woodward E. M. S., and Smyth, T. J. 2012. Seasonal dynamics of the carbonate system in the Western English Channel. Continental Shelf Research, 42, 30 - 40. doi:10.1016/j.csr.2012.04.012

BODC Processing

The data were received as 15 Excel files alongside 15 corresponding .xml files. These were archived according to BODC procedure. The data were then transferred to the BODC format and loaded to the database. During transfer the WOCE flags in the original Excel data files were mapped accordingly. Parameter codes defined in the BODC parameter dictionary were assigned to the originator's variable as shown in the table below:

Originator's Parameter Originator's Units Description BODC Parameter BODC Units Description
Lat decimal degrees Latitude (decimal degrees, N positive) ALATZZ01 degrees Latitude north
Lon decimal degrees Longitude (decimal degrees, E positive) ALONZZ01 degrees Longitude east
xCO2_equ µmol mol-1 Mole fraction CO2 measured for equilibrator sample (µmol/mol) XCO2WBDY Micromoles per mole Mole fraction (equilibrated marine sample) of : carbon dioxide (dry air)
xCO2_atm µmol mol-1 Mole fraction CO2 measured for marine air sample (µmol/mol) XCO2DRAT Micromoles per mole Mole fraction of carbon dioxide (dry air) in the atmosphere
xH2O_equ mmol mol-1 Mole fraction H2O in air from equilibrator (mmol/mol) WMXRZZ01 Millimoles per mole Mixing ratio (equilibrated marine sample) of water vapour
P_atm hPa Atmospheric pressure measured by Li-Cor at time of marine air measurement (hPa) CAPHZZ01 Milibars Pressure (measured variable) exerted by the atmosphere
P_equilib hPa Pressure of equilibration (hPa) PRES00EQ Milibars Pressure (in measurement loop for equilibrated marine sample)
T_equ deg C Equilibrator water temperature (deg C, average of the two eqilibrator PRTs used) TEMPEQMN Degrees Celsius Temperature (of equilibration)
T_sea deg C Sea surface temperature (deg C, from Ferrybox) TEMPP901 Degrees Celsius Temperature (ITS-90) of the water body
S_sea unitless Sea surface salinity (from Ferrybox) PSALZZXX Dimensionless Practical salinity of the water body by computation using UNESCO 1983 algorithm
pCO2_sw µatm Partial pressure CO2 in seawater (µatm) PCO2XXXX Microatmospheres Partial pressure of carbon dioxide {pCO2} in the water body
pCO2_atm µatm Partial pressure CO2 in marine air (µatm) ACO2XXXX Microatmospheres Partial pressure of carbon dioxide {pCO2} in the atmosphere
fCO2_sw µatm fugacity CO2 in seawater (µatm) FCO2XXXX Microatmospheres Fugacity of carbon dioxide (at 100% humidity) {fCO2} in the water body
fCO2_atm µatm fugacity CO2 in marine air (µatm) FCO2WTAT Microatmospheres Fugacity of carbon dioxide (at 100% humidity) in the atmosphere
Sub-flag   Only for use with WOCE flag 3. See table below for more information ACFLPCO2 Dimensionless Data quality flag (pCO2 IOCCP)

Originator's Flags

Only used with WOCE flag 3

Flag value Sub-flag description BODC Flag
1 Outside of standard range N/A
2 Questionable/interpolated T_sea N/A
3 Questionable T_equ L
4 Anomalous T_equ - T_sea (±1.0°C) L
5 Questionable S_sea N/A
6 Questionable P_atm N/A
7 Low equilibrator gas flow N/A
8 Questionable air value N/A
9 interpolated standard * N/A
10 Other: See QC Comments N/A

* NB: 9 = interpolated standard, so is only used if consecutive measures of the same standard are missing i.e. each standard is measured every third cycle so if 1st and 4th cycle are missing then this is counted as an extra interpolation so flagged

Project Information

UKOARP Theme A: Observations and synthesis to establish variability and trends of oceanic pH

This theme covers a programme of observations, combined with analysis of past and ongoing time series, to determine the magnitude of surface pH variations at seasonal-up-to-decadal time scales. Locations addressed will be the North Atlantic, UK shelf and slope waters, and selected locations in the Southern Ocean and Nordic Seas, using data from time series stations and volunteer observing ships (VOS), measuring three parameters of the marine carbonate system. The observations will be integrated with previous and ongoing international efforts, contributing to the SOCAT dataset, and to the internationally quality-controlled data relevant to ocean pH.


  • To quantify the rate of progression of ocean acidification in the Atlantic (including European shelf and slope), Southern and Arctic Ocenas, including identification of when/where CaCO3 undersaturation will occur first.
  • To quantify spatial and/or seasonal variability of carbonate system parameters in these areas.
  • To improve quantification of the rate of oceanic CO2 uptake in these areas.

This theme will maintain/upgrade the following existing pCO2 observations with discrete Total Alkalinity (TA) and Dissolved Inorganic Carbon (DIC) sampling for:

  • The UK/Caribbean "Geest" line
  • The Pride of Bilbao ferry line
  • The Western Channel Observatory (WCO) and Irish Sea Coastal Observatory (ISCO)
  • The RRS James Clark Ross (previously funded under CARBON-OPS)

New observations will be established covering:

  • Weekly sampling for TA and DIC in Ryder Bay at Rothera base by the British Antarctic Survey. This will expand the Rothera Oceanographic and Biological Time Series (RaTS) to include carbonate chemistry.
  • RV CEFAS Endeavour to be equipped with an underway pCO2 measurement system to improve coverage in the shelf seas around England and Wales.
  • RV CEFAS Endeavour to sample TA and DIC during scheduled work to build up a dataset for UK coastal waters.
  • CEFAS "Smartbuoy" sites to be sampled for TA and DIC upto eight times per year on regular service visits to build up time series for each site.


Data Activity or Cruise Information


Cruise Name 20/12 Part B
Departure Date 2012-12-03
Arrival Date 2012-12-05
Principal Scientist(s)David Brian Sivyer (Centre for Environment, Fisheries and Aquaculture Science Lowestoft Laboratory)
Ship RV Cefas Endeavour

Complete Cruise Metadata Report is available here

Fixed Station Information

No Fixed Station Information held for the Series

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