Metadata Report for BODC Series Reference Number 1350728

Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
Niskin bottle  discrete water samplers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Mr Mark Stinchcombe
Originating Organization National Oceanography Centre, Southampton
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) -

Data Identifiers

Originator's Identifier CE0716_CTD_NUTS_257:CTD02
BODC Series Reference 1350728

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2007-06-21 14:07
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -

Spatial Co-ordinates

Latitude 48.99900 N ( 48° 59.9' N )
Longitude 16.50200 W ( 16° 30.1' W )
Positional Uncertainty Unspecified
Minimum Sensor or Sampling Depth 5.0 m
Maximum Sensor or Sampling Depth 264.4 m
Minimum Sensor or Sampling Height 4575.6 m
Maximum Sensor or Sampling Height 4835.0 m
Sea Floor Depth 4840.0 m
Sea Floor Depth Source -
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


BODC CODERankUnitsTitle
ADEPZZ011MetresDepth below surface of the water body
BOTTFLAG1DimensionlessSampling process quality flag (BODC C22)
NTRZAATX1Micromoles per litreConcentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
PHOSAATX1Micromoles per litreConcentration of phosphate {PO43- CAS 14265-44-2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
ROSPOSID1DimensionlessBottle rosette position identifier
SAMPRFNM1DimensionlessSample reference number
SLCAAATX1Micromoles per litreConcentration of silicate {SiO44- CAS 17181-37-2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis

Definition of BOTTFLAG

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 supplied by Natural Environment Research Council (NERC)

You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."

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.


Bottles may be deployed singly clamped to a wire or in groups of up to 48 on a rosette. Standard bottles have a capacity between 1.7 and 30 L, while Lever Action bottles have a capacity between 1.7 and 12 L. Reversing thermometers may be attached to a spring-loaded disk that rotates through 180° on bottle closure.

CTD Bottle Nutrient Samples from Celtic Explorer Cruise CE0716

Data Acquisition and Analysis

Inorganic nutrients were sampled by the CTD rosette, mainly to allow the ISUS to be calibrated. A sterilin pot was rinsed three times and then filled two thirds with water. This was then frozen for transport back to NOCS.

The nutrients were analysed at NOCS using a Skalar SanPlus Autoanalyser for nitrate, nitrite, phosphate and silicate, using the methodology of Kirkwood (1996). The following calibrations were applied:

Further information about the sampling and processing of chlorophyll samples can be found in the cruise report

References Cited

Kirkwood, D. S., 1996. Nutrients: Practical notes on their determination in seawater. In: ICES Techniques in Marine Environmental Sciences Report 17, International Council for the Exploration of the Seas, Copenhagen (1996), p.25.

BODC Data Processing Procedures

The data arrived at BODC in an excel spreadsheet. This was then saved as a comma separated values (.csv) format file, containing calibrated nutrient data collected during the cruise.

Originator's Parameter Unit Description BODC Parameter Code BODC Unit Comments
Nitrate μM/l Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [unknown phase] by colorimetric autoanalysis NTRZAATX μM/l n/a
Silicate μM/l Concentration of silicate {SiO4} per unit volume of the water body [unknown phase] by colorimetric autoanalysis SLCAAATX μM/l n/a
Phosphate μM/l Concentration of phosphate {PO4} per unit volume of the water body [unknown phase] by colorimetric autoanalysis PHOSAATX μM/l n/a

The data values were plotted and checked for consistency, and as a result none were flagged.

Data Quality Issues

Data for CTD4, Rosette position 3, flagged, as the table in the cruise report does not show a sample being taken in that location.

Project Information

No Project Information held for the Series

Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2007-06-21
End Date (yyyy-mm-dd) 2007-06-21
Organization Undertaking ActivityNational Oceanography Centre, Southampton
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierCE0716_CTD_CTD02
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for CE0716_CTD_CTD02

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
207575   9      4.70    5.30    5.00 Niskin bottle No problem reported    
207576   8     10.00   11.50   10.70 Niskin bottle No problem reported    
207577   7     28.70   30.70   29.40 Niskin bottle No problem reported    
207578   5     87.90   89.80   88.10 Niskin bottle No problem reported    
207579   4    121.20  122.10  120.60 Niskin bottle No problem reported    
207580   3    164.10  164.90  163.00 Niskin bottle No problem reported    
207581   2    196.90  197.90  195.60 Niskin bottle No problem reported    
207582   1    266.60  267.00  264.40 Niskin bottle No problem reported    
209205   6     60.10   61.00   60.00 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.


Cruise Name CE0716
Departure Date 2007-06-19
Arrival Date 2007-06-25
Principal Scientist(s)Richard Stephen Lampitt (National Oceanography Centre, Southampton)
Ship Celtic Explorer

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