Metadata Report for BODC Series Reference Number 1224444


Metadata Summary

Data Description

Data Category Multiple data types -ship
Instrument Type
NameCategories
Sea-Bird SBE 45 MicroTSG thermosalinograph  thermosalinographs; water temperature sensor; salinity sensor
Vaisala PTB 210 digital barometer  meteorological packages
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_JR271_UKOA_DATAIV
BODC Series Reference 1224444
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2012-06-02 21:33
End Time (yyyy-mm-dd hh:mm) 2012-07-02 14:44
Nominal Cycle Interval 7200.0 seconds
 

Spatial Co-ordinates

Start Latitude 55.85850 N ( 55° 51.5' N )
End Latitude 64.28100 N ( 64° 16.9' N )
Start Longitude 2.26490 E ( 2° 15.9' E )
End Longitude 22.38780 W ( 22° 23.3' W )
Positional Uncertainty Unspecified
Minimum Sensor Depth 0.0 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 -
 

Parameters

No Parameters for BODC Reference Number = 1224444

 

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

UKOA Underway Atmospheric and Seawater pCO2 Data Quality Report - JR271 (JR20120601)

The quality controlled data received by BODC has no known data quality issues.


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 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

Specification

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 PTB210 Digital Barometer

The basic specifications for this pressure sensor are as follows:

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

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:

Specifications

  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 .

UKOA Underway Atmospheric and Seawater pCO2 Instrumentation Document - JR271 (JR20120601)

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

Instrument Serial Number Parameter Description BODC Parameter
SBE45 4524698-0016 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 PTB210 Barometer. Model PB100   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

UKOA Underway Atmospheric and Seawater pCO2 Processing Document - JR271 (JR20120601)

Originator's Processing Notes

Methodology

Continuous measurements of the partial pressure of CO 2 (pCO 2 ) in surface water and marine air were made throughout the cruise by infrared detection on a LI-COR LI-840. The ship's seawater supply provided water for underway sampling from 5 m depth at the bow to the main lab. Temperature and salinity of the intake water were determined by the ship's sensors.

Seawater flowed through an equilibrator. Part of the water went to waste via a bypass. The equilibrator was operated at a flow rate of 0.8 to 1.8 l min -1 . The water flow rate was recorded twice a day.

The system, comprising a shower-head equilibrator, infrared gas analyzer (LICOR, LI-840), processing and communication hardware, allows regular (20 min) sampling of seawater pCO 2 and atmospheric CO 2 , referenced against standard gases (Hardman-Mountford et al., 2008). Standard gases used for the calibration, nominally 250 ppmv, 380 ppmv and 450 ppmv CO 2 in air (BOC Ltd.), were separately 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.

The equilibrator headspace is vented to a second equilibrator, thereby allowing the former to draw seawater-equilibrated headspace from the latter if the pressure decreases ('vented system' configuration). The second equilibrator is vented to the atmosphere thereby maintaining pressure equilibrium. Inter-calibration tests showed agreement within 0.5 µatm between the new equilibrator Live pCO2 and similar systems.

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 separately. 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 variable 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

Screening

The data were screened using BODC in-house software, Edserplo.

One spike was flagged as suspect at cycle number 72 for parameter ACO2XXXX.

References

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.


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.

Weblink: http://www.oceanacidification.org.uk/research_programme/surface_ocean.aspx


Data Activity or Cruise Information

Cruise

Cruise Name JR20120601 (JR271)
Departure Date 2012-06-01
Arrival Date 2012-07-02
Principal Scientist(s)Ray Leakey (Scottish Association for Marine Science)
Ship RRS James Clark Ross

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