Metadata Report for BODC Series Reference Number 2296305

• 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

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

Niskin Bottle

The Niskin bottle is a device used by oceanographers to collect subsurface seawater samples. It is a plastic bottle with caps and rubber seals at each end and is deployed with the caps held open, allowing free-flushing of the bottle as it moves through the water column.

Standard Niskin

The standard version of the bottle includes a plastic-coated metal spring or elastic cord running through the interior of the bottle that joins the two caps, and the caps are held open against the spring by plastic lanyards. When the bottle reaches the desired depth the lanyards are released by a pressure-actuated switch, command signal or messenger weight and the caps are forced shut and sealed, trapping the seawater sample.

Lever Action Niskin

The Lever Action Niskin Bottle differs from the standard version, in that the caps are held open during deployment by externally mounted stainless steel springs rather than an internal spring or cord. Lever Action Niskins are recommended for applications where a completely clear sample chamber is critical or for use in deep cold water.

Clean Sampling

A modified version of the standard Niskin bottle has been developed for clean sampling. This is teflon-coated and uses a latex cord to close the caps rather than a metal spring. The clean version of the Levered Action Niskin bottle is also teflon-coated and uses epoxy covered springs in place of the stainless steel springs. These bottles are specifically designed to minimise metal contamination when sampling trace metals.

Deployment

Bottles may be deployed singly clamped to a wire or in groups of up to 48 on a rosette. Standard bottles and Lever Action bottles have a capacity between 1.7 and 30 L. Reversing thermometers may be attached to a spring-loaded disk that rotates through 180° on bottle closure.

Carbonate System Parameters for Meteor M27_1 and M30_1, Valdivia VLD137 and RRS Discovery DI217 cruises

Document History

Converted from CDROM documentation.

Content of data series

Data Originator

Meteor cruise

Mr Thomas Raabe, Hamburg University, Germany.

Sampling strategy and methodology

pH values were determined using a WTW pH meter. Note that these are not high precision measurements.

Comments on data quality

Meteor 27_1

The manometric TCO₂ measurements are systematically lower than results obtained coulometrically on the same samples by non-OMEX participants on the cruise and literature values from the same area, again determined coulometrically. The difference is approximately 1-2 per cent with the higher differences observed in samples collected from below 1000m depth. This has been attributed to uncertainty in the calibration volume and the data originator cites the coulometric values as more reliable.

There were a number of low value spikes reported in the data set which have been attributed to loss of gas volume during transfer operations on the line. These were removed from the data set prior to submission to BODC.

References

Dickson, A.G. 1990. Thermodynamics of the dissolciation of boric acid in synthetic seawater from 273.15 to 298.15 K . Deep Sea Research 37, 755 766.

Dickson, A.G., 1993. PH buffers for sea-water media based on the the total hydrogen-ion concentration scale. Deep-Sea Research, 40, 107-118.

Frankignoulle, M., Bourge, I., Canon, C., Dauby, P., 1986. Distribution of surface seawater partial CO₂ pressure in the English Channel and in the Southern Bight of the North Sea. Continental Shelf Research, 16, 381-395.

Frankignoulle, M., Elskens, M., Biondo R., Bourge, I., Canon, C., Desgain S. and P. Dauby, 1996. Distribution of inorganic carbon and related parameters in surface seawater of the English Channel during Spring 1994. Journal of Marine Systems, 7, 427-434.

Goyet, C., Poisson, A., 1989. New determination of carbonic-acid dissociation constants in sea-water as a function of temperature and salinity. Deep-Sea Research 36, 163-165.

Hansson, I., 1973. A new set of acidity constants for carbonic acid and boric acid in sea water. Deep Sea-Research 20, 461-478.

Roy, R.N., Roy, L.N., Vogel, K.M., Moore,C.P., Pearson,T., Good,C.E., Millero,F.J. and Cambell, 1993. Determination of the ionization constants of carbonic acid in seawater Marine Chemistry 44, 249 268.

Weiss, R.F., 1974. Carbon dioxide in seawater: the solubility of a non-ideal gas. Marine Chemistry 2, 203-215.

Project Information

Ocean Margin EXchange (OMEX) I

Introduction

OMEX was a European multidisciplinary oceanographic research project that studied and quantified the exchange processes of carbon and associated elements between the continental shelf of western Europe and the open Atlantic Ocean. The project ran in two phases known as OMEX I (1993-1996) and OMEX II - II (1997-2000), with a bridging phase OMEX II - I (1996-1997). The project was supported by the European Union under the second and third phases of its MArine Science and Technology Programme (MAST) through contracts MAS2-CT93-0069 and MAS3-CT97-0076. It was led by Professor Roland Wollast from Université Libre de Bruxelles, Belgium and involved more than 100 scientists from 10 European countries.

Scientific Objectives

The aim of the Ocean Margin EXchange (OMEX) project was to gain a better understanding of the physical, chemical and biological processes occurring at the ocean margins in order to quantify fluxes of energy and matter (carbon, nutrients and other trace elements) across this boundary. The research culminated in the development of quantitative budgets for the areas studied using an approach based on both field measurements and modeling.

OMEX I (1993-1996)

The first phase of OMEX was divided into sub-projects by discipline:

• Physics
• Biogeochemical Cycles
• Biological Processes
• Benthic Processes
• Carbon Cycling and Biogases

This emphasises the multidisciplinary nature of the research.

The project fieldwork focussed on the region of the European Margin adjacent to the Goban Spur (off the coast of Brittany) and the shelf break off Tromsø, Norway. However, there was also data collected off the Iberian Margin and to the west of Ireland. In all a total of 57 research cruises (excluding 295 Continuous Plankton Recorder tows) were involved in the collection of OMEX I data.

Data Availability

Field data collected during OMEX I have been published by BODC as a CD-ROM product, entitled:

• OMEX I Project Data Set (two discs)

Further descriptions of this product and order forms may be found on the BODC web site.

The data are also held in BODC's databases and subsets may be obtained by request from BODC.

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for M27_1_CTD_159401

Please note:the supplied parameters may not have been sampled from all the bottle firings described in the table above. Cross-match the Sample Reference Number above against the SAMPRFNM value in the data file to identify the relevant metadata.

Related Data Activity activities are detailed in Appendix 1

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:

Appendix 1: M27_1_CTD_159401

Related series for this Data Activity are presented in the table below. Further information can be found by following the appropriate links.

If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.