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Metadata Report for BODC Series Reference Number 1787487


Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
NameCategories
Niskin bottle  discrete water samplers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Dr Carol Robinson
Originating Organization Plymouth Marine Laboratory
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) Atlantic Meridional Transect Phase2(AMT)
 

Data Identifiers

Originator's Identifier AMT12_CTD_DOXY_57:AMT12_36
BODC Series Reference 1787487
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2003-05-30 06:28
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 1.08671 N ( 1° 5.2' N )
Longitude 25.64634 W ( 25° 38.8' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor or Sampling Depth 12.0 m
Maximum Sensor or Sampling Depth 301.1 m
Minimum Sensor or Sampling Height 3441.1 m
Maximum Sensor or Sampling Height 3730.2 m
Sea Floor Depth 3742.2 m
Sea Floor Depth Source PEVENT
Sensor or Sampling Distribution Unspecified -
Sensor or Sampling Depth Datum Unspecified -
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODERankUnitsTitle
ADEPZZ011MetresDepth (spatial coordinate) relative to water surface in the water body
BOTTFLAG1Not applicableSampling process quality flag (BODC C22)
DOXYWITX1Micromoles per litreConcentration of oxygen {O2 CAS 7782-44-7} per unit volume of the water body [dissolved plus reactive particulate phase] by Winkler titration
SAMPRFNM1DimensionlessSample reference number

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

Open 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.

If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:

"Contains public sector information licensed under the Open Government Licence v1.0."


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.

AMT12 Oxygen sample concentrations

Originator's Protocol for Data Acquisition and Analysis

This data originates from analyses on samples collected from 66 CTD casts and 12 samples taken from the non-toxic supply during the cruise. Water samples were taken directly from the bottles in the Sea-Bird CTD rosette system using silicon tubing.

Dissolved oxygen concentration was determined by automated Winkler titration with photometric end-point detection (Williamson and Jenkinson, 1982).

References Cited

Williams P.J.leB. and Jenkinson N.W., 1982. A transportable micro processor controlled precise Winkler titration suitable for field station and shipboard use. Limnology and Oceanography, 27, 576-584.

Instrumentation Description

Not applicable for this data set.

BODC Data Processing Procedures

Data were submitted via email in an Excel spreadsheet archived under BODC's accession number PML030111. Sample metadata (CTD cast, date, latitude, longitude, bottle number and depth) were checked against information held in the database. There were no discrepancies.

The concentration data were provided in micromoles per litre. These units for the concentration data were consistent with the BODC parameter code units and no conversion was applied.

The data were reformatted and loaded in BODC's samples database under Oracle Relational Database Management System. Data were marked up with BODC parameter codes and loaded into the database. Individual samples were matched through rosette sampling bottle and depth.

A parameter mapping table is provided below;

Originator's Parameter Units Description BODC Parameter Code Units Comments
Oxygen concentration (mean) by titration µmol l-1 Concentration of oxygen {O2} per unit volume of the water body [dissolved phase] by Winkler titration DOXYWITX µmol l-1 n/a

Data Quality Report

BODC was not advised of any specific quality issues with the data. The data were checked visually and used for the calibration of the CTD sensor. No values were flagged by BODC.

Problem Report

Not relevant to this data set.


Project Information

The Atlantic Meridional Transect - Phase 2 (2002-2006)

Who was involved in the project?

The Atlantic Meridional Transect Phase 2 was designed by and implemented by a number of UK research centres and universities. The programme was hosted by Plymouth Marine Laboratory in collaboration with the National Oceanography Centre, Southampton. The universities involved were:

  • University of Liverpool
  • University of Newcastle
  • University of Plymouth
  • University of Southampton
  • University of East Anglia

What was the project about?

AMT began in 1995, with scientific aims to assess mesoscale to basin scale phytoplankton processes, the functional interpretation of bio-optical signatures and the seasonal, regional and latitudinal variations in mesozooplankton dynamics. In 2002, when the programme restarted, the scientific aims were broadened to address a suite of cross-disciplinary questions concerning ocean plankton ecology and biogeochemistry and the links to atmospheric processes.

The objectives included the determination of:

  • how the structure, functional properties and trophic status of the major planktonic ecosystems vary in space and time
  • how physical processes control the rates of nutrient supply to the planktonic ecosystem
  • how atmosphere-ocean exchange and photo-degradation influence the formation and fate of organic matter

The data were collected with the aim of being distributed for use in the development of models to describe the interactions between the global climate system and ocean biogeochemistry.

When was the project active?

The second phase of funding allowed the project to continue for the period 2002 to 2006 and consisted of six research cruises. The first phase of the AMT programme ran from 1995 to 2000.

Brief summary of the project fieldwork/data

The fieldwork on the first three cruises was carried out along transects from the UK to the Falkland Islands in September and from the Falkland Islands to the UK in April. The last three cruises followed a cruise track between the UK and South Africa, only deviating from the traditional transect in the southern hemisphere. During this phase the research cruises sampled further into the centre of the North and South Atlantic Ocean and also along the north-west coast of Africa where upwelled nutrient rich water is known to provide a significant source of climatically important gases.

Who funded the project?

Natural Environment Research Council (NERC)


Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2003-05-30
End Date (yyyy-mm-dd) 2003-05-30
Organization Undertaking ActivityPlymouth Marine Laboratory
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierAMT12_CTD_AMT12_36
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for AMT12_CTD_AMT12_36

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
507466 20.0           6.10       6.70       5.60 Niskin bottle No problem reported    
507467 20.0         11.70     12.20     11.20 Niskin bottle No problem reported    
507468 20.0         20.90     21.50     20.40 Niskin bottle No problem reported    
507469 20.0         37.90     38.60     37.30 Niskin bottle No problem reported    
507470 20.0         67.90     71.80     68.70 Niskin bottle No problem reported    
507471 20.0       132.10   132.80   130.90 Niskin bottle No problem reported    
507472 20.0       202.00   203.30   200.70 Niskin bottle No problem reported    
507489 20.0         12.60     13.10     12.00 Niskin bottle No problem reported    
507490 20.0       101.10   101.50   100.00 Niskin bottle No problem reported    
507551 20.0         56.60     57.20     55.80 Niskin bottle No problem reported    
507552 20.0       303.50   303.90   301.10 Niskin bottle No problem reported    
518000 20.0         71.40     71.70     72.00 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 JR20030512 (AMT12, JR102, JR88, JR90)
Departure Date 2003-05-12
Arrival Date 2003-06-17
Principal Scientist(s)Tim Jickells (University of East Anglia School of Environmental Sciences)
Ship RRS James Clark Ross

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: AMT12_CTD_AMT12_36

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 IdentifierData CategoryStart date/timeStart positionCruise
1124885Water sample data2003-05-30 06:28:001.08671 N, 25.64634 WRRS James Clark Ross JR20030512 (AMT12, JR102, JR88, JR90)
1869285Water sample data2003-05-30 06:28:001.08671 N, 25.64634 WRRS James Clark Ross JR20030512 (AMT12, JR102, JR88, JR90)
1887777Water sample data2003-05-30 06:28:001.08671 N, 25.64634 WRRS James Clark Ross JR20030512 (AMT12, JR102, JR88, JR90)