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Metadata Report for BODC Series Reference Number 1271406


Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
NameCategories
General Oceanics GO-FLO water sampler  discrete water samplers
Instrument Mounting lowered unmanned submersible
Originating Country Belgium
Originator Prof Lei Lei
Originating Organization Free University of Brussels, Laboratory of Chemical Oceanography and Water Geochemistry
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) OMEX I
 

Data Identifiers

Originator's Identifier BG9322A_CTD_NUTS_14:GC05B
BODC Series Reference 1271406
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1993-09-26 09:52
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 49.11844 N ( 49° 7.1' N )
Longitude 13.42365 W ( 13° 25.4' W )
Positional Uncertainty Unspecified
Minimum Sensor or Sampling Depth 396.6 m
Maximum Sensor or Sampling Depth 1576.6 m
Minimum Sensor or Sampling Height -
Maximum Sensor or Sampling Height -
Sea Floor Depth -
Sea Floor Depth Source -
Sensor or Sampling Distribution Unspecified -
Sensor or Sampling Depth Datum Unspecified -
Sea Floor Depth Datum Unspecified -
 

Parameters

BODC CODERankUnitsTitle
ADEPZZ011MetresDepth (spatial coordinate) relative to water surface in the water body
BOTTFLAG1Not applicableSampling process quality flag (BODC C22)
SAMPRFNM1DimensionlessSample reference number
SLCAMATX1Micromoles per litreConcentration of silicate {SiO44- CAS 17181-37-2} per unit volume of the water body [dissolved plus reactive particulate phase] by manual colorimetric analysis

Definition of BOTTFLAG

BOTTFLAGDefinition
0The sampling event occurred without any incident being reported to BODC.
1The filter in an in-situ sampling pump physically ruptured during sample resulting in an unquantifiable loss of sampled material.
2Analytical evidence (e.g. surface water salinity measured on a sample collected at depth) indicates that the water sample has been contaminated by water from depths other than the depths of sampling.
3The feedback indicator on the deck unit reported that the bottle closure command had failed. General Oceanics deck units used on NERC vessels in the 80s and 90s were renowned for reporting misfires when the bottle had been closed. This flag is also suitable for when a trigger command is mistakenly sent to a bottle that has previously been fired.
4During the sampling deployment the bottle was fired in an order other than incrementing rosette position. Indicative of the potential for errors in the assignment of bottle firing depth, especially with General Oceanics rosettes.
5Water was reported to be escaping from the bottle as the rosette was being recovered.
6The bottle seals were observed to be incorrectly seated and the bottle was only part full of water on recovery.
7Either the bottle was found to contain no sample on recovery or there was no bottle fitted to the rosette position fired (but SBE35 record may exist).
8There is reason to doubt the accuracy of the sampling depth associated with the sample.
9The bottle air vent had not been closed prior to deployment giving rise to a risk of sample contamination through leakage.

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

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

Nutrients for cruises Belgica BG9309, BG9322, BG9412, BG9506, BG9521 and BG9522, Charles Darwin CD84 and RRS Discovery DI216

Document History

Converted from CDROM documentation.

Content of data series

AMONAAD2 Dissolved ammonium
Colorometric autoanalysis (0.4/0.45 µm pore filtered)
Micromoles/litre
AMONAATX Dissolved ammonium
Colorometric autoanalysis (unfiltered)
Micromoles/litre
AMONMATX Ammonium (unfiltered)
Manual colorometric analysis (unfiltered)
Micromoles/litre
NTRIAAD2 Dissolved nitrite
Colorometric autoanalysis (0.4/0.45 µm pore filtered)
Micromoles/litre
NTRIAAD5 Dissolved nitrite
Colorometric autoanalysis (0.2 µm pore filtered)
Micromoles/litre
NTRIAATX Nitrite (unfiltered)
Colorometric autoanalysis (unfiltered)
Micromoles/litre
NTRZAAD2 Dissolved nitrate + nitrite
Colorometric autoanalysis (0.4/0.45 µm pore filtered)
Micromoles/litre
NTRZAAD5 Dissolved nitrate + nitrite
Colorometric autoanalysis (0.2 µm pore filtered)
Micromoles/litre
NTRZAATX Nitrate + nitrite (unfiltered)
Colorometric autoanalysis (unfiltered)
Micromoles/litre
PHOSAAD2 Dissolved phosphate
Colorometric autoanalysis (0.4/0.45 µm pore filtered)
Micromoles/litre
PHOSAAD5 Dissolved phosphate
Colorometric autoanalysis (0.2 µm pore filtered)
Micromoles/litre
PHOSAATX Phosphate (unfiltered)
Colorometric autoanalysis (unfiltered)
Micromoles/litre
PHOSMATX Phosphate (unfiltered)
Manual colorometric analysis (unfiltered)
Micromoles/litre
SLCAAAD2 Dissolved silicate
Colorometric autoanalysis (0.4/0.45 µm pore filtered)
Micromoles/litre
SLCAAAD5 Dissolved silicate
Colorometric autoanalysis (0.2 µm pore filtered)
Micromoles/litre
SLCAAATX Silicate (unfiltered)
Colorometric autoanalysis (unfiltered)
Micromoles/litre
SLCAMATX Silicate (unfiltered)
Manual colorometric analysis (unfiltered)
Micromoles/litre
UREAMDTX Urea (unfiltered)
Manual analysis using the diacetylmonoxime method
Micromoles/litre

Data Originator

Dr Lei Chou, ULB, Brussels, Belgium.

Sampling strategy and methodology

Manual spectrophotometric analyses for phosphate, nitrite and silicate were done using the methods specified in Grasshoff et al. (1983). These analyses were usually carried out on board ship as soon after sampling as possible. Samples were kept refrigerated and dark between collection and analysis.

Samples for nutrient determination by autoanalysis were kept frozen until analysed. A separate set of samples were usually taken specifically for silicate analysis and stored in the dark, chilled but not frozen. Samples were analysed on a SKALAR autoanalyser.

Comments on data quality

Belgica cruise 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.

Belgica cruise BG9412

On this cruise the ULB NO3+NO2 data, with the exception of a handful of points, are significantly lower than the VUB data. Differences of 10 per cent and more are predominant throughout the overlapping data set.

The phosphate and nitrite data sets show excellent agreement.

Charles Darwin cruise CD84

Both ULB and SOC measured the nitrate+nitrite profile at the Belgica station. The two data sets show very good agreement.

Discovery cruise DI216

Nutrients were measured by three groups on this cruise: nitrate+nitrite, silicate and phosphate were measured by SOC; phosphate was determined manually by ULB; nitrate+nitrite and silicate were determined by the Galway group.

The ULB and SOC phosphate data show very good agreement. ULB reported some phosphate samples contaminated and these have been flagged 'L' in the database.

The SOC data are believed to be of extremely high quality. Indeed the data were used successfully to identify CTD rosette misfires due to the close proximity of the values from unintentional 'blind duplicates'. The only problem encountered with the SOC data were the nitrate+nitrite values for one cast (CTD4) which were obviously low. This was attributed to the reduction column being poisoned by mercury in an internal standard and the data have been flagged.

The Galway data from CTD bottles were compared with the SOC data and flagged if they deviated from the SOC values by more than 10 per cent. The same 'blind duplicates' described above were analysed by Galway but the replication was very poor. Users are recommended to use the SOC data rather than the Galway data whenever possible.

Samples from the continuous sea water supply were not analysed by SOC. The Galway data are erratic and in many cases incredibly high. With the exception of samples taken on a section up the Channel right up to the Solent, surface nitrate+nitrite values in excess of 0.75 µM and silicate values in excess of 1.0 µM have been flagged suspect by BODC. The remaining data should be used with caution.

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.

GO-FLO Bottle

A water sampling bottle featuring close-open-close operation. The bottle opens automatically at approximately 10 metres and flushes until closed. Sampling with these bottles avoids contamination at the surface, internal spring contamination, loss of sample on deck and exchange of water from different depths.

There are several sizes available, from 1.7 to 100 litres and are made of PVC with a depth rating of up to 500 m. These bottles can be attached to a rosette or placed on a cable at selected positions.


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

Cruise Name BG9322A
Departure Date 1993-09-22
Arrival Date 1993-09-29
Principal Scientist(s)Roland Wollast (Free University of Brussels, Laboratory of Chemical Oceanography and Water Geochemistry)
Ship RV Belgica

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:

Flag Description
Blank Unqualified
< Below detection limit
> In excess of quoted value
A Taxonomic flag for affinis (aff.)
B Beginning of CTD Down/Up Cast
C Taxonomic flag for confer (cf.)
D Thermometric depth
E End of CTD Down/Up Cast
G Non-taxonomic biological characteristic uncertainty
H Extrapolated value
I Taxonomic flag for single species (sp.)
K Improbable value - unknown quality control source
L Improbable value - originator's quality control
M Improbable value - BODC quality control
N Null value
O Improbable value - user quality control
P Trace/calm
Q Indeterminate
R Replacement value
S Estimated value
T Interpolated value
U Uncalibrated
W Control value
X Excessive difference

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Flag Description
0 no quality control
1 good value
2 probably good value
3 probably bad value
4 bad value
5 changed value
6 value below detection
7 value in excess
8 interpolated value
9 missing value
A value phenomenon uncertain
Q value below limit of quantification