Metadata Report for BODC Series Reference Number 887706

• 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

AML Conductivity Temperature Depth profiler CTD-12

A self-contained CTD with platinized 4-electrode glass conductivity cell, pressure-protected thermistor temperature sensor and a semiconductor strain gauge pressure sensor plus integral data logger. The instrument package was superseded by the AML CTD-12 plus.

FV An Cappall Ban CAPB1 CTD Data Documentation

Instrumentation

The CTD profiles were taken with an Applied Microsystems STD 12 plus CTD system incorporating a Keller stainless steel pressure transducer, a precision thermistor and a four platinised electrode conductivity cell.

Prior to use, a check of the sensors was done by running the instrument in a water bath. A single Niskin bottle was sometimes clamped to the wire above the CTD to take calibration samples. On other SEFOS cruises the package was mounted in a CTD rosette frame allowing a more thorough calibration to be undertaken.

Data Acquisition and UCG Processing

The instrument included an internal data logger that sampled at up to 8 Hz. However, internal memory restrictions (7,500 record capacity at the time of this cruise) dictated that lower sampling rates be used. Data from the CTD were downloaded onto a PC, binned to 1db and converted into engineering units in ASCII format using software supplied with the instrument.

A calibration offset of -0.015 has been applied to the salinity data by UCG based upon an extensive calibration against bottle data during SEFOS cruise Heinke 71 in May 1995.

BODC Data Processing and Quality Control

Reformatting

The data were converted into the BODC internal format (PXF) to allow the use of in-house software tools, notably the graphics editor.

Editing

Using a custom in-house graphics editor, the limits of the downcasts were manually flagged. In addition, spikes on all the downcast channels were manually flagged 'suspect' by modification of the associated quality control flag. In this way none of the original data values were edited or deleted during quality control.

Once screened on the workstation, the CTD downcasts were loaded into a database under the Oracle relational database management system.

Calibration

No additional calibrations have been applied to the data by BODC.

Data Reduction

Once all screening and calibration procedures were completed, the data set was binned to 2 db (casts deeper than 100 m) or 1 db (casts shallower than 100 m). 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.

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: