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Metadata Report for BODC Series Reference Number 1280366

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 Malcolm Woodward
Originating Organization Plymouth Marine Laboratory
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) -

Data Identifiers

Originator's Identifier CD132_CTD_NUTS_62:CD132_001
BODC Series Reference 1280366

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2001-09-03 01:33
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -

Spatial Co-ordinates

Latitude 0.91153 S ( 0° 54.7' S )
Longitude 64.14168 E ( 64° 8.5' E )
Positional Uncertainty Unspecified
Minimum Sensor or Sampling Depth 1.6 m
Maximum Sensor or Sampling Depth 296.1 m
Minimum Sensor or Sampling Height 3996.7 m
Maximum Sensor or Sampling Height 4291.2 m
Sea Floor Depth 4292.8 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 (spatial coordinate) relative to water surface in the water body
AMONNATX1Micromoles per litreConcentration (nM sensitivity) of ammonium {NH4+ CAS 14798-03-9} per unit volume of the water body [dissolved plus reactive particulate phase] by nanomolar ammonium system after Jones (1991)
BOTTFLAG1Not applicableSampling process quality flag (BODC C22)
NTRIAATX1Micromoles per litreConcentration of nitrite {NO2- CAS 14797-65-0} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
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.

Dissolved nutrient data series for cruise Charles Darwin CD132

Content of Data Series

Parameter Unit Parameter Code Number of stations Comments
Ammonium µmol/l AMONAATX 322 None
Ammonium (nanomolar system) µmol/l AMONNATX 71 None
Nitrate+Nitrite (LWCC) µmol/l NTRZLWTX 50 None
Nitrate+Nitrite µmol/l NTRZAATX 567 None
Nitrite µmol/l NTRIAATX 558 None
Phosphate µmol/l PHOSAATX 561 None
Silicate µmol/l SLCAAATX 556 None

Originator's Protocol for Data Acquisition and Analysis

The following methodology was compiled from information extracted from the CD132 cruise report (Burkill 2002) and from information provided by the originator.

Samples for nutrient analyses were collected from water sampled using the CTD rosette system equipped with 24x20L Niskin sampling bottles. Samples were collected at 36 CTD stations including pre-dawn casts (biogeochemistry, primary production, and nitrogen uptake and regeneration experiments) generally down to 300m, deep casts down to 2500m and mid-day high vertical resolution sampling casts.

Water samples were sub-sampled into acid-cleaned 60 ml HDPE (Nalgene) bottles. Analysis for the nutrient samples was in every case complete within 3 hours of sampling. Clean handling techniques were employed to avoid any contamination of the samples, particularly by ammonium. Samples were analysed without pre-filtration. No samples were stored.

The nutrient analyser was the five-channel Technicon AAII segmented flow autoanalyser. The chemical methodologies used were according to Brewer and Riley (1965) for nitrate, Grasshoff (1976) for nitrite, Kirkwood (1989) for phosphate and silicate, and Mantoura and Woodward (1983) for ammonium.

The nanomolar ammonium system is an adaptation from Jones (1991) which uses a fluorescence analysis technique following ammonia gas diffusion out of the samples, passing across a hydrophobic teflon membrane due to pH differential chemistry.

All CTD samples were analysed with a negligible sample loss rate. The ageing Technicon 5-channel system showed its reliability and reproducibility in the extreme environment of tropical, on-board deployment.

The ammonium fluorescence system performed well early in the cruise before developing a severe loss of sensitivity, which was diagnosed as a fluorometer problem. The system was inoperable for the second half of the cruise and the colorimetric system using the Technicon auto-analyser was used for the remainder of the cruise with good performance.

This cruise was the first deployment of a new unique multi-channel nanomolar analyser combining the segmented flow colorimetric analytical techniques with a Liquid Waveguide Capillary Cell (LWCC). The system is still essentially a developmental analyser. Of the two channels available during the cruise, one was used for the analysis of nitrate and nitrite while the other channel was used to develop the phosphate system into an operational unit. The nitrate channel operated successfully at a sensitivity of about 1 nanomole or better and performed well for the majority of the cruise. Due to lack of time and modern high-precision equipment, it was not possible to make the phosphate channel operate to any sort of acceptable level.


Brewer PG, Riley JP (1965). The automatic determination of nitrate in seawater. Deep-Sea Res. 12: 765-772.

Burkill PH (2002). RRS Charles Darwin cruise 132. Analysing the Microbial Biodiversity of the Indian Ocean - AMBITION. 30 Aug-29 Sep 2001. Marine and Freshwater Microbial Biodiversity Cruise Report No.1, 56pp.

Grasshoff K (1976). Methods of seawater analysis. Verlag Chemie, Weiheim: 317 pp.

Jones RD (1991). An improved fluorescence method for the determination of nanomolar concentrations of ammonium in natural waters. Limnol. and Oceanogr. 36:814-819.

Kirkwood D (1989). Simultaneous determination of selected nutrients in sea water. International Council for the Exploration of the Sea (ICES), CM 1989/C:29.

Mantoura RFC, Woodward EMS (1983). Optimization of the indophenol blue method for the automated determination of ammonia in estuarine waters. Estuarine Coastal and Shelf Science 17:219-224.

BODC Data Processing Procedures

Data were submitted to BODC in an Excel spreadsheet. Sample metadata were checked against information held in the database and any discrepancy was checked with the data originator. Parameter codes defined in BODC parameter dictionary were assigned to the variables. Data were then loaded into BODC's Research Project Database under an Oracle Relational Database Management System without modification except for the following:

  • For CTD132_20, two samples were taken at 60m. This was not a depth recording error (confirmed by originator) and a mean of the pair of values was loaded into the BODC database.
  • For Nitrate+Nitrite measured by LWCC (parameter code NTRZLWTX), values were converted from nanomoles per litre to micromoles per litre.
  • A record was not loaded for CTD132_006 at 5m - this depth is in the submitted data but not the Seabird profile, as the bottle did not close at this depth. The record was removed on the advice of the originator.
  • For CTD132_024 the original file shows two samples at 25m. The Seabird profile showed one sample at 25m and one at 35m. This was corrected after advice from originator that it was a typing error.
  • For CTD132_001, the original file wrongly shows two samples at 10m. The depth profile was adjusted to conform to the Seabird profile after confirmation from the originator.
  • In the original data file, the column heading "Nitrate = [NO3]: nanomolar" refers to the measurement of NO3 plus NO2 by LWCC (confirmed by originator).
  • The data in the column headed "[NO3]" in the original file has not been included as this was derived from the subtraction of the "[NO2-]" column values from the "[NO3]+[NO2]" values.
  • For NH4 measured by the ammonium nanoanalyser, no conversion of units was performed as the data appeared to be presented in micromoles/litre.

Data Quality Report

Although the quality of the data is not affected by what follows, users should be aware that:

Project Information

No Project Information held for the Series

Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2001-09-03
End Date (yyyy-mm-dd) 2001-09-03
Organization Undertaking ActivityPlymouth Marine Laboratory
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierCD132_CTD_CD132_001
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for CD132_CTD_CD132_001

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
142282   20.00      297.90  298.10  296.10 Niskin bottle No problem reported    
142284   20.00      198.80  200.90  198.70 Niskin bottle No problem reported    
142285   20.00      149.60  150.10  149.00 Niskin bottle No problem reported    
142287   20.00      119.20  119.60  118.70 Niskin bottle No problem reported    
142289   20.00       99.50  100.50   99.40 Niskin bottle No problem reported    
142291   20.00       73.80   74.30   73.60 Niskin bottle No problem reported    
142293   20.00       58.80   59.10   58.60 Niskin bottle No problem reported    
142294   20.00       61.80   62.10   61.60 Niskin bottle No problem reported    
142295   20.00       49.70   50.80   50.00 Niskin bottle Leakage contamination    
142297   20.00       25.00   26.70   25.70 Niskin bottle No problem reported    
142299   20.00       11.10   11.50   11.20 Niskin bottle No problem reported    
142302   20.00        6.00    6.40    6.20 Niskin bottle No problem reported    
142304   20.00        1.30    1.90    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 CD132 (AMBITION)
Departure Date 2001-08-30
Arrival Date 2001-09-29
Principal Scientist(s)Peter H Burkill (Plymouth Marine Laboratory)
Ship RRS Charles Darwin

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: CD132_CTD_CD132_001

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
1655078Water sample data2001-09-03 01:33:000.91153 S, 64.14168 ERRS Charles Darwin CD132 (AMBITION)