Metadata Report for BODC Series Reference Number 1266023

• 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

Technicap NOEX bottle

The Technicap NOEX water bottle was designed for oceanographic sampling. The bottle comprises a plastic tube with caps at each end and is deployed with the caps held open, then closed at the target depth. Multiple bottles can be deployed on a CTD frame rosette. Bottle capacity is variable, but normally several litres. The bottle was developed by Technicap in the 1990s but has been superseded by more recent models. There is no known source of support available for this sampler.

Nutrients for cruises Belgica BG9309, Charles Darwin CD86 and Pelagia PLG93 and PLG95B

Document History

Converted from CDROM documentation.

Content of data series

Data Originator

Dr Wim Helder, NIOZ, Texel, the Netherlands.

Sampling strategy and methodology

Samples were taken from water bottles deployed on a CTD rosette and analysed at sea using a TRAACS 80 autoanalyser, usually within 4 hours of collection. Samples were stored in cool and dark conditions between collection and analysis.

On cruise Pelagia 93, the samples from the CTD rosette were analysed unfiltered. On Charles Darwin 86 and Pelagia 95, the samples were filtered through a 0.45 micron acrodisc filter to improve the quality of the ammonium results.

The following chemistries were used:

Samples were always analysed from the surface to the bottom to minimise the risk of cross-sample contamination.

Working standards were freshly prepared daily by diluting stock standards to the required concentration with natural, aged, low-nutrient seawater. The nutrient concentrations in this were determined by manual colorometric analysis. The low-nutrient seawater was also used as a wash between samples. A second mixed nutrient stock, poisoned with 0.2% chloroform or 20 mg/l HgCl₂, was used as an independent check. Pipettes and volumetric flasks were calibrated before each cruise and standard batches were intercalibrated.

Accuracy of analyses is reported as about 1% of the full scale value for nitrate, nitrite and silicate and 2% of the full scale for phosphate and ammonium.

The data were reported as nitrate and nitrite, the nitrate values having been computed by subtracting nitrite from nitrate plus nitrite. BODC practice is to store nitrate plus nitrite and the values in the database have been determined by summing the nitrate and nitrite values supplied. In cases where multiple bottles were fired at a single depth, nutrient values were reported from each bottle. These have been averaged, excluding any bottles flagged as leaking, to give a single nutrient value for each depth.

Comments on data quality

Belgica BG9309

The SKALAR autoanalyser phosphate data were supplied with a warning that there may be problems. On a number of stations all three laboratories provided phosphates and for a number of stations there were also manually analysed phosphates from ULB. Comparing these data it can be clearly seen that the SKALAR values are frequently way too high. Consequently, the SKALAR phosphate data set has been flagged 'L'.

For the stations where inter-comparison of NO₃+NO₂ data is possible, the ULB data are generally higher than the VUB data which are, in turn, generally higher than the CSIC data. None of the data have been flagged. Users are advised to retrieve all three data sets and reach their own conclusions about which data to use.

References

Armstrong, F.A.J., Stearns, C.R. and Strickland, J.D.H., 1967. The measurement of upwelling and subsequent biological processes by means of the Technicon Autoanalyser and associated equipment. Deep Sea Res. 14, 381-389.

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.

Elskens, I. and Elskens, M., 1989. Handleing voor de bepaling van nutrienten in zeewater met an Autoanalyser IITM systeem. Vrije Universiteit Brussel, 50pp..

Føyn, L., Magnussen, M. and Seglem, K., 1981. Automatisk analyse av naeringsalter med "on-line" databehandling. En presentasjon av oppbyggning og virkemåte av systemet i bruk på Havforskningsinstituttets båter og i laboratoriet. Fisken Hav., Ser. B., 4, 1-40.

Goeyens, L,. Kindermans, N., Yusuf, M.A. and Elskens, M. (submitted 1996). A room temperature procedure for the manual determination of urea in seawater. Submitted to Marine Chemistry.

Grasshoff, K., Ehrhardt, M. and Kremling, K. eds. 1983. Methods of seawater analysis. Verlag Chemie.

Koroleff, F., 1969. Direct determination of ammonia in natural waters as indophenol blue. Int. Counc. Explor. Sea, CM., 9, 19-22.

Mourino, C. and Fraga, F., 1985. Determinacion de nitratos en aqua de mar. Investigacion Pesquera, 49, 81-96.

Mulvena, P. and Savidge, G., 1992. A modified manual method for the determination of urea in seawater using diacetylmonoxime reagent. Estuarine, Coastal and Shelf Science, 34, 429-438.

Murphy, J. and Riley, J.P., 1962. A modified single solution method for the determination of phosphate in natural waters. Analytica Chim. Acta, 27, 31-36.

Rees, A.P., Owens, N.J.P. and Woodward, E.M.S. (1995). Phytoplankton nitrogen assimilation at low nutrient concentrations in the NW Mediterranean Sea. Water Pollution Research Report 32 in EROS 2000 ed J-M Martin and H. Barth, European Commission, 141-148.

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 PLG95B_CTD_04_1

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.

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: