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Metadata Report for BODC Series Reference Number 1304585

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 Dr Peter Saunders
Originating Organization Southampton Oceanography Centre (now National Oceanography Centre, Southampton)
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) UK WOCE

Data Identifiers

Originator's Identifier DI230_CTD_NUTS_129:A25CTD095
BODC Series Reference 1304585

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1997-09-03 19:01
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -

Spatial Co-ordinates

Latitude 61.71328 N ( 61° 42.8' N )
Longitude 36.58763 W ( 36° 35.3' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor or Sampling Depth 1.6 m
Maximum Sensor or Sampling Depth 2708.4 m
Minimum Sensor or Sampling Height 12.5 m
Maximum Sensor or Sampling Height 2719.3 m
Sea Floor Depth 2720.9 m
Sea Floor Depth Source -
Sensor or Sampling Distribution Unspecified -
Sensor or Sampling Depth Datum Unspecified -
Sea Floor Depth Datum Unspecified -


BODC CODERankUnitsTitle
ADEPZZ011MetresDepth (spatial coordinate) relative to water surface in the water body
BOTTFLAG1Not applicableSampling 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
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 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.

D230 Discrete CTD Inorganic Nutrient Sampling Document

Originator's Protocol for Data Acquisition and Analysis

Sample collection and analysis

Discrete dissolved inorganic nutrient samples were collected from Niskin bottles fired on 141 CTD casts performed during D230. Samples were collected in 30 ml plastic diluvial sample cups, each washed three times in the sample flow. Samples were stored in a fridge (up to a maximum of four hours duration) prior to onboard analysis. 8 ml subsamples were drawn into sample cups and run on the SOC Chemlab AAII-type Auto-Analyser connected to a digital-analysis microstream data capture and reduction system. Duplicates were analysed to ensure accuracy and to increase precision.

Primary standards were prepared in calibrated 500 ml glass volumetric flasks (calibrated polyethylene volumetric flasks for silicate), one standard solution for each nutrient being required for the cruise. These utilised pre-weighed salts measured prior to the cruise. Sets of working standards were typically made up from these on a daily basis in 100 ml calibrated polyethylene volumetric flasks, using artificial seawater (40 g/l NaCl). These were run in duplicate prior to each analytical run to enable sample calibration. Independent quality control samples were also prepared from standard solutions supplied by OSI and run (in duplicate) at intervals throughout the analysis.

The cruise report contains more in depth details of each nutrient analysis performed during the cruise.

BODC Data Processing Procedures

ASCII-formatted CTD sample data from this cruise were supplied to BODC during March 2001. The inorganic nutrient data were extracted from these files and loaded into BODC's Oracle database. Flags were assigned if values were considered suspect.

Content of data series

Originator's Parameter Unit Description BODC Parameter code BODC Unit Comments
SiO3 µmol/l Concentration of silicate per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis SLCAAATX µmol/l No unit conversion necessary
NO2+NO3 µmol/l Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis NTRZAATX µmol/l No unit conversion necessary
PO4 µmol/l Concentration of phosphate per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis PHOSAATX µmol/l No unit conversion necessary


Bacon, S., (1998). RRS Discovery Cruise 230, 07 AUG - 17 SEP 1997. FOUREX. Cruise Report No. 16 Southampton Oceanography Centre.

Project Information


The UK made a substantial contribution to the international World Ocean Circulation Experiment (WOCE) project by focusing on two important regions:

  1. Southern Ocean - links all the worlds oceans, controlling global climate.
  2. North Atlantic - directly affects the climate of Europe.

A major part of the UK effort was in the Southern Ocean and work included:

  • Two surveys, in the South Atlantic as part of the WOCE Hydrographic Programme.
  • SWINDEX, a year long study of the Antarctic Circumpolar Current (ACC) where it crosses major topography south of Africa.
  • ADOX, a study of deep water flow from the Atlantic to the Indian Ocean.
  • ACCLAIM, a study of the ACC by altimetry and island measurements.

In the North Atlantic the UK undertook:

  • NATRE, a purposeful tracer experiment to look at cross isopycnic processes.
  • CONVEX, a study of the deep ocean circulation and its changes.
  • VIVALDI, a seven year programme of seasonally repeated surveys to study the upper ocean.
  • Long-term observations of ocean climate in the North West Approaches.

Satellite ocean surface topography, temperature and wind data were merged with in situ observations and models to create a complete description of ocean circulation, eddy motion and the way the ocean is driven by the atmosphere.

The surveys were forerunners to the international Global Ocean Observing System (GOOS). GOOS was later established to monitor annual to decadal changes in ocean circulation and heat storage which are vital in the prediction of climate change.

Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 1997-09-03
End Date (yyyy-mm-dd) 1997-09-03
Organization Undertaking ActivitySouthampton Oceanography Centre (now National Oceanography Centre, Southampton)
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierDI230_CTD_A25CTD095
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for DI230_CTD_A25CTD095

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
114942   10.00     2752.80 2754.30 2708.40 Niskin bottle No problem reported    
114943   10.00     2606.90 2608.40 2565.70 Niskin bottle No problem reported    
114944   10.00     2405.80 2407.30 2368.80 Niskin bottle No problem reported    
114946   10.00     1998.00 1999.50 1969.10 Niskin bottle No problem reported    
114947   10.00     1797.50 1799.00 1772.30 Niskin bottle No problem reported    
114949   10.00     1390.70 1392.20 1372.40 Niskin bottle No problem reported    
114950   10.00     1184.40 1185.90 1169.30 Niskin bottle No problem reported    
114951   10.00      988.20  989.70  976.00 Niskin bottle No problem reported    
114952   10.00      823.70  825.20  813.80 Niskin bottle No problem reported    
114953   10.00      720.70  722.20  712.20 Niskin bottle No problem reported    
114954   10.00      617.80  619.30  610.60 Niskin bottle No problem reported    
114955   10.00      514.40  515.90  508.50 Niskin bottle No problem reported    
114956   10.00      411.30  412.80  406.60 Niskin bottle No problem reported    
114957   10.00      309.30  310.80  305.70 Niskin bottle No problem reported    
114958   10.00      207.20  208.70  204.70 Niskin bottle No problem reported    
114959   10.00      156.10  157.60  154.20 Niskin bottle No problem reported    
114960   10.00       53.80   55.30   52.90 Niskin bottle No problem reported    
114961   10.00       28.20   29.70   27.50 Niskin bottle No problem reported    
114962   10.00       12.70   14.20   12.20 Niskin bottle No problem reported    
114963   10.00        2.00    3.50    1.60 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 Name D230
Departure Date 1997-08-07
Arrival Date 1997-09-17
Principal Scientist(s)Sheldon Bacon (Southampton Oceanography Centre)
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: DI230_CTD_A25CTD095

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
2131136Water sample data1997-09-03 19:00:3061.71328 N, 36.58763 WRRS Discovery D230