Metadata Report for BODC Series Reference Number 1623562

Metadata Summary

Data Description

Data Category Multiple data types
Instrument Type
Vaisala PTB100 barometric pressure sensor  meteorological packages
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-840 CO2 and H2O gas analyser  atmospheric gas analysers
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Dr Vassilis Kitidis
Originating Organization Plymouth Marine Laboratory
Processing Status QC in progress
Project(s) UKOARP_ThemeB

Data Identifiers

Originator's Identifier BODC_PCO2_PML_D366_UKOA_20131212_DATAI
BODC Series Reference 1623562

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2011-06-06 14:27
End Time (yyyy-mm-dd hh:mm) 2011-07-09 07:41
Nominal Cycle Interval 300.0 seconds

Spatial Co-ordinates

Southernmost Latitude 45.38071 N ( 45° 22.8' N )
Northernmost Latitude 60.00274 N ( 60° 0.2' N )
Westernmost Longitude 12.01167 W ( 12° 0.7' W )
Easternmost Longitude 10.01248 E ( 10° 0.7' E )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth -15.0 m
Maximum Sensor Depth 6.0 m
Minimum Sensor Height -
Maximum Sensor Height -
Sea Floor Depth -
Sensor 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 Depth Datum Approximate - Depth is only approximate
Sea Floor Depth Datum -


No Parameters for BODC Reference Number = 1623562


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

UK Ocean Acidification Underway Atmospheric and Seawater pCO2, Cruise D366,PML pCO2 Data Quality Report

There are no known issues with these 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

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

General Information

The LI-840 and 840A CO 2 /H 2 O 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


CO 2

  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 CO 2 /ppt H 2 O N/A

H 2 O

  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 CO 2 <0.0001 ppt <0.0001 ppt H 2 O/ppm CO 2

(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 .

Vaisala Analog Barometers Models PTB100 (A), (B) and PTB101 (B), (C)

The PTB 100 series analog barometers are designed both for accurate barometric measurements at room temperature and for general environmental pressure monitoring over a wide temperature range. The long-term stability of the barometer minimizes the need for field adjustment in many applications.

Physical Specifications

Size 97 x 60 x 22 mm
Weight 85g

The barometers use the BAROCAP * silicon capacitive absolute pressure sensor developed by Vaisala for barometric pressure measurements. The BAROCAP * sensor combines the elasticity characteristics and mechanical stability of a single-crystal silicon with the proven capacitive detection principle.

Sensor Specifications

Model Number Pressure Range
Temperature Range
Humidity Range Total Accuracy
PTB100A 800 to 1060 -40 to +60 non-condensing +20 °C ± 0.3 mbar
0 to +40 °C ± 1.0 mbar
-20 to +45 °C ± 1.5 mbar
-40 to +60 °C ± 2.5 mbar
PTB100B 600 to 1060 -40 to +60 non-condensing +20 °C ± 0.5 mbar
0 to +40 °C ± 1.5 mbar
-20 to +45 °C ± 2.0 mbar
-40 to +60 °C ± 3.0 mbar
PTB101B 600 to 1060 -40 to +60 non-condensing +20 °C ± 0.5 mbar
0 to +40 °C ± 1.5 mbar
-20 to +45 °C ± 2.0 mbar
-40 to +60 °C ± 3.0 mbar
PTB101C 900 to 1100 -40 to +60 non-condensing +20 °C ± 0.3 mbar
0 to +40 °C ± 1.0 mbar
-20 to +45 °C ± 1.5 mbar
-40 to +60 °C ± 2.5 mbar

* BAROCAP is a registered trademark of Vaisala

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:


  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 .

UK Ocean Acidification Underway Atmospheric and Seawater pCO2, Cruise D366,PML pCO2 Processing Document

Originator's Processing Notes


An automated pCO2 measurement system (Live pCO2) (Hardman-Mountford et al., 2008) was installed on the UK NERC research vessels (RRS Discovery). The system used a vented-shower-head equilibrator and an infrared detection (LI-COR, LI-840). In order to maintain atmospheric pressure in the equilibrator headspace, the latter was vented to a second equilibrator, which in turn was vented to the atmosphere via a 2 m coil of stainless steel tubing (1.5 mm internal diameter). The equilibrator was fitted with 2 platinum resistance thermometers and a water-jacket supplied with seawater from the underway system. The average warming between the ship's underway seawater intake and the equilibrator was 0.45±0.05°C. Atmospheric measurements were taken from an intake located on the foremast. Both the equilibrator and atmospheric gas streams were dried in a Peltier cooler (-20°C). Measurements were referenced against standard CO 2 in synthetic air mixtures (0, 251.3 and 446.9 µmol CO2?mol-1) which were referenced against certified US National Oceanic and Atmospheric Administration (NOAA) standards (244.94 ppmv and 444.37 ppmv CO 2 in air) in the laboratory prior to deployment.

Data Processing - Equations

The LivepCO 2 instrument measures CO 2 dry mole fraction (xCO 2 dry ). This is used to compute pCO 2 (pCO 2 equ ) at the equilibrator temperature (T equ ) and pressure (P equ ):

pCO 2 equ = xCO 2 dry * (P equ - pH 2 O)

pH 2 O is the water vapour pressure at T equ (Weiss and Price, 1980):

pH 2 O = exp(24.5443 - 67.4509 * (100/T equ ) - 4.8489 * ln(T equ /100) -0.000544 * Salinity)

Finally, pCO 2 at sea surface temperature is calculated according to the following equation (Takahashi et al., 1993):

pCO 2 SST = pCO 2 equ * exp(0.0423 * (SST - T equ ))

Corresponding atmospheric pCO 2 measurements are interpolated from measurements immediately before and after xCO 2 dry measurements (circa 10 minutes).

BODC Processing Notes

Data were submitted to BODC as an Excel .xlsx file containing metadata and data on one sheet. This was subsequently archived alongside two .csv files containing the data and metadata resepctively. The data were then transferred to the BODC format and loaded to the database. Parameter codes defined in the BODC dictionary were assigned to the variables as shown in the table below:

Originator's Parameter Originator's Units Comments BODC Parameter BODC Units Description
LAT +ve N   ALATZZ01 Degrees Latitude north
LON +ve E   ALONZZ01 Degrees Longitude east
SST °C   TEMPP901 Degrees Celsius Temperature (ITS-90) of the water body
Salinity dimensionless   PSALZZXX Dimensionless Practical salinity of the water body by computation using UNESCO 1983 algorithm
xCO2dry micromole CO2/mole dry air   XCO2WBDY Micromoles per mole Mole fraction (equilibrated marine sample) of carbon dioxide (dry air)
Tequ °C   TEMPEQMN Degrees Celsius Temperature (of equilibration)
Pequ hecta-Pascal   PRES00EQ Millibars Pressure (in measurement loop for equilibrated marine sample)
pCO2 SST micromole   PCO2XXXX Microatmospheres Partial pressure of carbon dioxide {pCO2} in the water body
pCO2atm micromole   ACO2XXXX Microatmospheres Partial pressure of carbon dioxide {pCO2} in the atmosphere
Patm hecta-Pascal   CAPHZZ01 Millibars Pressure (measured variable) exerted by the atmosphere


The data were visualised using the bespoke BODC software EDSERPLO with suspicious values flagged where appropriate.

There was a period of time where the latitude and longitude appeared to be stationary for a large period of time, from 26/06/2011 10:50:00 to 26/06/2011 20:09:00. These position values were all flagged as suspect, 'M'. The cruise underway data is available upon request.

A spike was flagged suspect, 'M', in the pressure channels CAPHZZ01 and PRES00EQ. In addition to this flag a few values were flagged as suspect, 'M', in the salinity channel, PSALZZXX.

In the pCO 2 channels, XCO2WBDY and PCO2XXXX, a few data were flagged suspect, 'M', where it looked like the instrument was adjusting to being turned and/or cleaned.


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

Takahashi, T., J. Olafsson, J.G. Goddard, D.W. Chipman, S.C. Sutherland (1993) Seasonal variation of CO2 and nutrients in the high-latitude surface oceans: a comparative study. Global Biogeochemical Cycles 7, 843-878.

Weiss, R.F., Price, B.A., 1980. Nitrous-Oxide Solubility in Water and Seawater. Marine Chemistry 8, 347-359.

UK Ocean Acidification Underway Atmospheric and Seawater pCO2, Cruise D366,PML pCO2 Instrumentation Document

The following instruments and the parameters they measured are given below:

Instrument Serial Number Parameter Description BODC Parameter
SBE45 0230 Sea Surface Temperature, Sea Surface Salinity TEMPP901, PSALZZXX
Pico-Technology platinum resistance thermometers in equilibrator. Model PT100 B Class   Equilibrated temperature TEMPEQMN
LICOR LI-840   Equilibrator Pressure PRES00EQ
Vaisala PTB100A Barometer. Model PTB100A S3440012 Atmospheric Pressure CAPHZZ01
LI-COR LI-840   Partial pressure of carbon dioxide in the water body, partial pressure of carbon dioxide in the atmosphere PCO2XXXX, ACO2XXXX

Project Information

UKOARP Theme B: Ocean acidification impacts on sea surface biology, biogeochemistry and climate

The overall aim of this theme is to obtain a quantitative understanding of the impact of ocean acidification (OA) on the surface ocean biology and ecosystem and on the role of the surface ocean within the overall Earth System.

The aims of the theme are:

The main consortium activities will consist of in-situ measurements on three dedicated cruises, as well as on-deck bioassay experiments probing the response of the in-situ community to elevated CO2. Most of the planned work will be carried out on the three cruises to locations with strong gradients in seawater carbon chemistry and pH; the Arctic Ocean, around the British Isles and the Southern Ocean.


Data Activity or Cruise Information


Cruise Name D366 (D367)
Departure Date 2011-06-06
Arrival Date 2011-07-09
Principal Scientist(s)Eric Pieter Achterberg (University of Southampton School of Ocean and Earth Science)
Ship RRS Discovery

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