Metadata Report for BODC Series Reference Number 1868614

• 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

Non-toxic (underway) sea water supply

A source of uncontaminated near-surface (commonly 3 to 7 m) seawater pumped continuously to shipboard laboratories on research vessels. There is typically a temperature sensor near the intake (known as the hull temperature) to provide measurements that are as close as possible to the ambient water temperature. The flow from the supply is typically directed through continuously logged sensors such as a thermosalinograph and a fluorometer. Water samples are often collected from the non-toxic supply. The system is also referred to as the underway supply.

Dissolved Organic Carbon and Total Nitrogen for cruises Belgica BG9919B, Charles Darwin CD110B, Meteor M43_2 and Professor Shtokman ST0898

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 non-toxic supply and filtered through GF/F filters. The filtrates were acidified, transferred to flame-sealed, pre-ashed glass ampoules and stored in a refrigerator until analysed. Ultra-clean handling techniques were used throughout.

The analytical technique involves the direct injection of acidified and decarbonated seawater onto a platinised alumina catalyst at high temperature (680-900 °C) under an atmosphere of oxygen or high purity air. Quantitative production of CO₂ gas allows DOC concentrations to be determined using a CO₂-specific infrared gas analyser (IRGA).

A Shimadzu TOC-5000 HTCO analyser was used. This was fitted with a LiCor Li6252 IRGA for DOC determination and Antek 705-D chemiluminescence detector for TDN determination. The combustion products travelled through a Drierite trap (97% CaSO₄, 3% CoCl₃) and a membrane (permeation tube) drier to remove any trace of water. 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. A more detailed description of the protocols followed may be found in Miller et al. (1993).

Comments on data quality

Some of the TDN values from CD110 and ST0898 were up to 5 µM lower than the corresponding nitrate+nitrite values from the nutrient data set.

A significant proportion of the TDN data from M43_2 was flagged as suspect by the data originator, with very good reason. Users are therefore advised not to ignore the quality control flags when using the data.

References

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) II - II

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 II - II (1997-2000)

The second phase of OMEX concentrated exclusively on the Iberian Margin, although RV Belgica did make some measurements on La Chapelle Bank whilst on passage to Zeebrugge. This is a narrow-shelf environment, which contrasts sharply with the broad shelf adjacent to the Goban Spur. This phase of the project was also strongly multidisciplinary in approach, covering physics, chemistry, biology and geology.

There were a total of 33 OMEX II - II research cruises, plus 23 CPR tows, most of which were instrumented. Some of these cruises took place before the official project start date of June 1997.

Data Availability

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

• OMEX II Project Data Set (three 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

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: