Metadata Report for BODC Series Reference Number 915788

• 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

Zullig Hydropolytester profiler

Zullig Hydropolytester profiler

The Zullig probe is a low resolution probe, specifically designed for data collection in estuaries and coastal areas. Due to its characteristics it allows for the identification of water masses with different characteristics, like coastal and estuarine water masses, but it is not effective when trying distinguish between water masses with similar characteristics, e.g. Atlantic and Mediterranean water masses.

Below is a table with the sensors specifications:

RV Auriga PLUTUR2 CTD Data Documentation

Instrumentation and Shipboard Protocols

The CTD profiles were taken with a Hydropolytester/Nephelometer ZULLIG probe, including pressure, temperature, salinity, dissolved oxygen, pH and optical backscatter sensors. No water bottle rosette was included in the package.

BODC Data Processing and Quality Control

Reformatting

ASCII files were supplied to BODC and contained temperature (°C), depth (m), pH (pH units), conductivity (mmho/cm), oxygen (units unknown), turbidity (standard turbidity units (ftu)) and salinity (PSU). The data were converted into the BODC internal format (PXF). In addition to reformatting, the transfer program computed a sigma-theta channel (using the standard UNESCO subroutines POTEMP and SVAN) and converted depths to pressures (using the inverse of UNESCO function PTODEP).

Editing and Quality Control

Using a custom in-house graphics editor, the limits of the downcast were manually flagged and any obvious spikes identified were flagged 'suspect'.

Once screened, the CTD downcasts (between the flagged limits) were loaded into a database under the Oracle relational database management system.

The pH and dissolved oxygen channels contained values that were either all zero or obviously erroneous. After consultation with the data originator, these channels were deleted. The salinity data were very noisy in parts, particularly on temperature gradients, and sometimes required heavy flagging. The temperature and nephelometer data were much cleaner.

Calibrations

No sample data were available to calibrate any of the channels. All data are therefore the result of originator's calibrations of unknown date and no guarantee can be given as to the accuracy of the data.

Data Reduction

Once all screening and calibration procedures were completed, the data set was binned to 2 db (casts deeper than 100 db) or 1 db (casts shallower than 100 db). The binning algorithm excluded any data points flagged suspect and attempted linear interpolation over gaps up to 3 bins wide. If any gaps larger than this were encountered, the data in the gaps were set null.

Data Warnings

No independent checks, such as reversing thermometer data or salinity bottle data, were available for the verification of the temperature and salinity data. The absolute accuracy of these channels is therefore unknown.

The temperature and salinity data were supplied to 2 decimal places, implying low accuracy. Visual inspection of the salinity channel supported this impression. Users are advised not to use the salinity data from this cruise for applications requiring high (>0.05 PSU) accuracy.

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

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: