Metadata Report for BODC Series Reference Number 2296330

• 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

Dissolved Total Nitrogen and Phosphorus

Document History

Converted from CDROM documentation.

Content of data series

Data Originator

Dr Axel Miller, Plymouth Marine Laboratory, UK.

Sampling strategy and methodology

Samples were taken from the CTD rosette or surface sea water supply and filtered through GF/F filters. Ultra-clean handling techniques were used throughout.

The analytical technique involves the direct injection of acidified and decarbonated sea water onto a platinised alumina catalyst at high temperature (680-900 °C) under an atmosphere of oxygen or high purity air. Quantitative production of the nitric oxide radical allows total dissolved nitrogen concentrations to be determined using a nitrogen-specific chemiluminescence detector.

Analyses were undertaken at sea using a Shimadzu TOC-5000 HTCO analyser fitted with an Antek 705-D chemiluminescence detector. The combustion products travelled through a Drierite trap (97% CaSO₄, 3% CoCl₃) and a membrane (permeation tube) drier to remove any trace of water. The dried nitric acid radical was then reacted with ozone to produce the excited chemiluminescent nitrogen species and passed to the detector. Each sample was injected four times with each injection cycle taking 5.5 minutes.

Great care was taken to quantify blank signals generated at all stages of the analytical procedure and to correct the data for them.

References

Eberlein, K. and Kattner, G. 1987. Automatic method for the determination of ortho-phosphate and total dissolved phosphorus in the marine environment. Fresenius Z. anal. Chem., 326, 354-357.

Dissolved and Colloidal Organic Carbon for cruises Meteor M27_1 and M30_1 and Valdivia VLD137

Document History

Converted from CDROM documentation.

Content of data series

Data Originator

Mr Thomas Raabe, Hamburg University, Germany.

Sampling strategy and methodology

Water samples were taken from the CTD rosette and filtered through Whatman GF/C filters. The filtrate was poisoned with mercuric chloride and stored in glass and polythene bottles in a cooling chamber until analysed. Samples were analysed by high temperature catalytic oxidation using a nickel catalyst.

Comments on data quality

Meteor 27_1 and 30_1

The bulk of the water samples was analysed for DOC by both Bremen and Hamburg universities. The Hamburg data are systematically 2-3 times higher than the Bremen data. The cause of this is unknown. The Bremen data exhibit excellent agreement with the PML data collected on cruise Charles Darwin 84 which went to sea the day after Meteor 27_1 docked.

The Hamburg data set included 6 samples from Meteor 27_1, usually from rosette position 1, which showed exceptionally high DOC values. These have been flagged suspect. Three unusually high values (5-10 times the Bremen value) from Meteor 30_1 have also been flagged suspect.

Valdivia 137

The DOC values from this cruise are systematically higher than those obtained by other groups working in the OMEX project. On the two Meteor cruises, Hamburg and Bremen determined DOC on the same samples. The Hamburg results were consistently 2-3 times higher than the Bremen data.

A small number of data points from VLD137 are extremely high, with the odd sample exceeding 2000 M. Values in excess of 400 M have been flagged suspect.

References

Cauwet, G. 1994. HTCO method for dissolved organic carbon analysis in seawater: influence of catalyst on blank estimation, Marine Chemistry, 47, 55 64.

Miller, A.E.J, Mantoura, R.F.C., Preston, M.R. and Suzuki, Y, 1993. Preliminary study of DOC in the Tamar Estuary, UK, using UV-persulphate and HTCO techniques. Mar. Chem., 41, 223-228.

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_049401

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

Fixed Station Information

OMEX I Moored Instrument and CTD site OMEX2

OMEX2 was one of four fixed stations for the OMEX I project. It was visited by twelve cruises and collected a variety of data during the period June 1993 to October 1995. These include:

• Mooring deployments - Aandeera current meters with transmissometers
• CTD casts
• Net trawls
• Plankton recorders
• Cores
• Water samples

The data collected a site OMEX2 lay within a box bounded by co-ordinates 49° 6.72'N, 013° 16.03'W at the southwest corner and 49° 17.2'N, 012° 44.4'W at the northeast corner, with an approximate depth of 1500 metres.

Related Fixed Station activities are detailed in Appendix 2

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_049401

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.

Appendix 2: OMEX I site OMEX2

Related series for this Fixed Station 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.