Metadata Report for BODC Series Reference Number 907291

• 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

D320 DMS (atmos) Data Quality Report

As part of the originator's QC procedures, erroneous values and contaminated measurements were replaced by absent data values. Contamination events occurred when winds coming from the stern sector of the ship blew exhaust into the sampling system and chemically interfered with the measurements. The data were inspected visually at BODC and no further action was taken

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

D320 DMS (atmos) BODC Data Processing

The data were provided to BODC in tab delimited text file format representing the one minute resolution atmospheric dimethyl sulphide concentration data collected during the UK SOLAS DOGEE-II cruise D320. TThese were reformatted to the BODC internal QXF (NetCDF) format with time as the single dimension using BODC transfer function 410. The following table shows how the DMS variables were mapped to the appropriate BODC parameter codes:

The reformatted data were visualised using the in-house EDSERPLO screening software.

D320 DMS (atmos) External Data Processing

Sampling and Analytical Methodology

Atmospheric DMS concentrations were measured using an atmospheric pressure ionisation mass spectrometer with an isotopically labeled internal standard (APIMS-ILS). The inlet for the atmospheric samples was located at 22.2 m above the sea surface on the foremast of the RRS Discovery. An isotopically labeled standard (d3-DMS) was continuously added to the sample air at the inlet. The spiked ambient air was delivered to the APIMS via a 5/8'' internal diameter tube at a rate of 120 L min^-1 where 4 L min^-1 were sub-sampled by the APIMS. Protonated molecular ions at mass 63 (DMS-H+) and mass 66 (d3-DMS-H+) were monitored sequentially. Signal intensities were recorded as total ion counts in a 20 millisecond interval at each mass. The ambient DMS concentration was calculated from the signal ratio (mass63/mass66), the flow rate and concentration of the labeled standard, and the total sample air flow rate. DMS concentrations were condensed to minute-averages. Instrument backgrounds (blanks) were obtained by passing zero air instead of sample air to the system and were subsequently subtracted from total counts before calculating the DMS concentration. The time lag of the transport of the sample air through the tubing to the APIMS was also taken into consideration during calculations. Including the uncertainties from flow rate, standard concentration and blanks, precision of the mean DMS concentration is about 10~15%.

Project Information

UK SOLAS, Deep Ocean Gas Exchange Experiment (DOGEE)

This project was led by Newcastle University, in collaboration with: University of Southampton; Plymouth Marine Laboratory; National Oceanography Centre, Southampton; University of East Anglia. The multidisciplinary team aimed to provide a holistic study of the exchange rates of gases important in biogeochemical cycles.

Fieldwork comprised of two dedicated open ocean research cruises in the North Atlantic Ocean: D313 and D320. During D320 an artifical surfactant patch was successfully deployed and sampled. The observational data include:

• sea state, whitecapping and wave breaking
• bubble properties
• surfactants
• air-sea gas fluxes

Complimentary measurements were made by US-based research groups who participated in both cruises.

More detailed information on this project may be found in the official cruise reports for the DOGEE cruises, D313 andD320.

Weblink: http://www.nerc.ac.uk/research/programmes/solas/

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: