Metadata Report for BODC Series Reference Number 1207428

• Metadata Summary

• Problem Reports

• Data Access Policy

• Narrative Documents

• Project Information

• Data Activity or Cruise Information

• Fixed Station Information

• BODC Quality Flags

• SeaDataNet Quality Flags

Metadata Summary

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.

Specification

CO₂

H₂O

⁽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

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.

^* 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

Specifications

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.

Processing

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.

Submission

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

References

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 Flags

Only used with WOCE flag 3

^* 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.

Aims:

• 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.

Weblink: http://www.oceanacidification.org.uk/research_programme/co2_uptake.aspx

Data Activity or Cruise Information

Cruise

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:

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle: