Metadata Report for BODC Series Reference Number 2124650
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
Data Description |
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Data Identifiers |
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Time Co-ordinates(UT) |
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Spatial Co-ordinates | |||||||||||||||||||||||||
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Parameters |
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Definition of BOTTFLAG | |||||||||||||||||||||||||
BOTTFLAG | Definition |
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0 | The sampling event occurred without any incident being reported to BODC. |
1 | The filter in an in-situ sampling pump physically ruptured during sample resulting in an unquantifiable loss of sampled material. |
2 | Analytical 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. |
3 | The 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. |
4 | During 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. |
5 | Water was reported to be escaping from the bottle as the rosette was being recovered. |
6 | The bottle seals were observed to be incorrectly seated and the bottle was only part full of water on recovery. |
7 | Either 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). |
8 | There is reason to doubt the accuracy of the sampling depth associated with the sample. |
9 | The bottle air vent had not been closed prior to deployment giving rise to a risk of sample contamination through leakage. |
Definition of Rank |
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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
Niskin Bottle
The Niskin bottle is a device used by oceanographers to collect subsurface seawater samples. It is a plastic bottle with caps and rubber seals at each end and is deployed with the caps held open, allowing free-flushing of the bottle as it moves through the water column.
Standard Niskin
The standard version of the bottle includes a plastic-coated metal spring or elastic cord running through the interior of the bottle that joins the two caps, and the caps are held open against the spring by plastic lanyards. When the bottle reaches the desired depth the lanyards are released by a pressure-actuated switch, command signal or messenger weight and the caps are forced shut and sealed, trapping the seawater sample.
Lever Action Niskin
The Lever Action Niskin Bottle differs from the standard version, in that the caps are held open during deployment by externally mounted stainless steel springs rather than an internal spring or cord. Lever Action Niskins are recommended for applications where a completely clear sample chamber is critical or for use in deep cold water.
Clean Sampling
A modified version of the standard Niskin bottle has been developed for clean sampling. This is teflon-coated and uses a latex cord to close the caps rather than a metal spring. The clean version of the Levered Action Niskin bottle is also teflon-coated and uses epoxy covered springs in place of the stainless steel springs. These bottles are specifically designed to minimise metal contamination when sampling trace metals.
Deployment
Bottles may be deployed singly clamped to a wire or in groups of up to 48 on a rosette. Standard bottles and Lever Action bottles have a capacity between 1.7 and 30 L. Reversing thermometers may be attached to a spring-loaded disk that rotates through 180° on bottle closure.
Dissolved Oxygen for cruise Discovery DI216
Document History
Converted from CDROM documentation.
Content of data series
DOXYPR01 | Beckman oxygen |
Beckman oxygen probe | |
Micromoles/litre | |
DOXYWITX | Winkler oxygen |
Winkler titration | |
Micromoles/litre | |
OXYSBB01 | Oxygen saturation (Bens.Kr./Beckman) |
Benson and Krause algorithm from Beckman data | |
Per Cent |
Data Originator
Dr David Hydes, Southampton Oceanography Centre, UK.
Sampling strategy and methodology
Water samples were taken from the CTD rosette into glass-stoppered bottles that were filled from the bottom and allowed to overflow. After addition of the Winkler reagents, the bottles were shaken vigorously for some considerable time. The samples were then titrated against thiosulphate.
The difference between the two methods was in the technique used for end-point detection. Peter Statham's method was photometric with the end point taken as the transmittance maximum as thiosulphate was added from a 1ml Dosimat unit controlled by a manual switch. David Hydes's method used two bright platinum electrodes which measured the depolarisation caused by iodine and iodide in solution. Thiosulphate was dispensed by an automatic Titrino unit with the results logged by a PC.
Comments on data quality
Cruise Discovery DI216
Two groups measured dissolved oxygen on this cruise using different end-point detection methods. The primary purpose of this was to intercalibrate the two systems and to improve procedures to ensure that WOCE precision standards (<0.1%) may be obtained regularly.
Duplicate samples were taken by the two groups from the first 10 casts of the cruise and produced results showing good agreement between the two data sets (slope = 0.9947: R2 = 98.74%). A small negative offset (-0.88) showed that David Hydes's method produced results that were systematically slightly lower.
Precision of each method was tested by taking duplicate samples from two bottles on each of the casts. This showed that 16% of the samples analysed by Peter Statham's method and 46% of the samples analysed by David Hydes's method achieved WOCE precision.
It may therefore be seen that the oxygen water bottle data from this cruise are of very high quality.
References
Aminot, A. and Chaussepied, M. (eds), 1983. Manuel des analyses chimiques en milieau marin. C.N. L'Exploitation des Oceans. 395 pp.
Benson, B.B., Krause D. (1984). The concentration and isotopic fractionation of oxygen dissolved in fresh water and sea water in equilibrium with the atmosphere. Limnol.Oceanogr., 29, 620-632.
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
Start Date (yyyy-mm-dd) | 1995-09-10 |
End Date (yyyy-mm-dd) | 1995-09-10 |
Organization Undertaking Activity | University of Southampton Department of Oceanography (now University of Southampton School of Ocean and Earth Science) |
Country of Organization | United Kingdom |
Originator's Data Activity Identifier | DI216_CTD_CTD45 |
Platform Category | lowered unmanned submersible |
BODC Sample Metadata Report for DI216_CTD_CTD45
Sample reference number | Nominal collection volume(l) | Bottle rosette position | Bottle firing sequence number | Minimum pressure sampled (dbar) | Maximum pressure sampled (dbar) | Depth of sampling point (m) | Bottle type | Sample quality flag | Bottle reference | Comments |
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553499 | 10.00 | 76.40 | 77.40 | 74.10 | Lever Action Niskin Bottle | No problem reported | ||||
553708 | 10.00 | 204.20 | 205.30 | 200.80 | Lever Action Niskin Bottle | No problem reported | ||||
553709 | 10.00 | 154.60 | 155.80 | 151.70 | Niskin bottle | No problem reported | ||||
553710 | 10.00 | 104.70 | 105.70 | 102.20 | Lever Action Niskin Bottle | No problem reported | ||||
553712 | 10.00 | 60.70 | 62.00 | 58.70 | Lever Action Niskin Bottle | No problem reported | ||||
553713 | 10.00 | 40.70 | 41.80 | 38.80 | Lever Action Niskin Bottle | No problem reported | ||||
553714 | 10.00 | 19.00 | 21.50 | 18.00 | Lever Action Niskin Bottle | No problem reported |
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.
Related Data Activity activities are detailed in Appendix 1
Cruise
Cruise Name | D216 |
Departure Date | 1995-08-26 |
Arrival Date | 1995-09-12 |
Principal Scientist(s) | Peter J Statham (University of Southampton Department of Oceanography) |
Ship | RRS Discovery |
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 |
B | nominal value |
Q | value below limit of quantification |
Appendix 1: DI216_CTD_CTD45
Related series for this Data Activity are presented in the table below. Further information can be found by following the appropriate links.
If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.
Series Identifier | Data Category | Start date/time | Start position | Cruise |
---|---|---|---|---|
1256840 | Water sample data | 1995-09-10 15:34:00 | 47.4204 N, 7.26306 W | RRS Discovery D216 |
2094450 | Water sample data | 1995-09-10 15:34:00 | 47.4204 N, 7.26306 W | RRS Discovery D216 |
2123333 | Water sample data | 1995-09-10 15:34:00 | 47.4204 N, 7.26306 W | RRS Discovery D216 |
2129710 | Water sample data | 1995-09-10 15:34:00 | 47.4204 N, 7.26306 W | RRS Discovery D216 |