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Metadata Report for BODC Series Reference Number 1253381

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 Sinhue Torres-Valdes
Originating Organization National Oceanography Centre, Southampton
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) ANDREX

Data Identifiers

Originator's Identifier JC030_CTD_NUTS_570:CTD26
BODC Series Reference 1253381

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2009-01-13 03:42
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -

Spatial Co-ordinates

Latitude 60.79633 S ( 60° 47.8' S )
Longitude 12.01133 W ( 12° 0.7' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor or Sampling Depth 7.8 m
Maximum Sensor or Sampling Depth 5454.3 m
Minimum Sensor or Sampling Height 45.7 m
Maximum Sensor or Sampling Height 5492.2 m
Sea Floor Depth 5500.0 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)
FIRSEQID1DimensionlessBottle firing sequence number
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

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.


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.

Inorganic nutrient measurements from CTD bottle samples collected during ANDREX cruise JC030

Originator's Protocol for Data Acquisition and Analysis

Water samples for the determination of nitrate and nitrite, phosphate and silicate were drawn from 20 litre Niskin bottles from a 24-rosette sampling system mounted on a Sea-Bird 9/11 plus CTD. The water samples were collected into 35 ml coulter counter vials and kept refrigerated at approximately 4°C until analysis, which usually commenced within 0.5 to 2.0 hours.

Concentrations of nitrate and nitrite, phosphate and silicate were determined by a Skalar SansPlus segmented autoanalyser following methods described by Kirkwood (1996), with the exception that the pump rates through the phosphate line were increased by a factor of 1.5, which improved reproducibility and peak shape. A dilution loop for the sample line of the silicate channel was also installed giving a 2.9 times dilution. This was done in anticipation of the very high silicate concentrations expected in the area to be sampled. Stations were run individually because there was a large gap ca. >8 hours between stations. Further details of the instrumentation setup can be seen in the cruise report.

An artificial seawater matrix (ASW) of 40 g l-1 sodium chloride was used as the inter-sample wash and standard matrix. The nutrient free status of this solution was checked by running Ocean Scientific International (OSI) nutrient free seawater on every run. A single set of mixed standards were made up by diluting 5 mMol solutions made from weighed dried salts in 1 l of ASW into 1 l plastic volumetric flasks. On setting up the laboratory all labware was washed with 10% HCl and rinsed with MQ water. The wash time and sample time of the autosampler were 90 seconds and the lines were washed daily with 0.5 mol l-1 sodium hydroxide and 10% Decon 90.

Data processing was undertaken using Skalar proprietary software and was done at regular intervals throughout the cruise. Time series of baseline, instrument sensitivity, calibration curve correlation coefficient, nitrate reduction efficiency and duplicate difference was compiled to check the performance of the autoanalyser over the course of the cruise.

References Cited

Kirkwood, D., 1996. Nutrients: Practical notes on their determinations in seawater. ICES Techniques in marine environmental sciences. 17, 1-25.

BODC Data Processing Procedures

All data were received in one Microsoft Excel format file. Data received were loaded into the BODC database using established BODC data banking procedures. One discrepancy was found between the data originator's metadata and the Sea-Bird .btl files and log sheets. The rosette position numbers 22 and 23 provided for CTD cast 27 were the wrong way round in comparison to the pressure values therefore these were swapped without referral with the data originator. In addition, the following changes were made; all WOCE quality control flags provided by the originator were converted into BODC standard flags, 2 (good) = no flag, 3 (questionable) = 'L', and all absent data values were removed. The data were screened in-house prior to loading. Data were then loaded without any further changes. The following table shows how the variables were mapped to appropriate BODC parameter codes:

Originator's Parameter Unit Description BODC Parameter Code BODC Unit Comments
EXPOCODE - Cruise - - -
CASTNO - CTD station number - - -
SAMPNO - Sample number - - Null values only
DATE - Year - - -
TIME - Time - - Null values only
LATITUDE - Latitude - - -
LONGITUDE - Longitude - - -
CTDPRS dbar CTD pressure - - -
CTDPRS_FLAG_W - CTD pressure flags - - Null values only
BTLNBR - Rosette position - - -
BTLNBR_FLAG_W - Bottle flags - - Null values only
Depth m Depth - - Null values only
Depth_FLAG_W - Depth flags - - Null values only
temp - CTD temperature - - -
temp_FLAG_W - CTD temperature flags - - Null values only
potemp - CTD potential temperature - - -
potemp_FLAG_W - CTD potential temperature flags - - Null values only
sal_cal - CTD salinity - - -
sal_cal_FLAG_W - CTD salinity flags - - Null values only
NO3 µmol l-1 Nitrate+nitrite NTRZAATX µmol l-1 -
NO3_FLAG_W - Nitrate+nitrite flags - - -
SiO4 µmol l-1 Silicate SLCAAATX µmol l-1 -
SiO4_FLAG_W - Silcate flags - - -
PO4 µmol l-1 Phosphate PHOSAATX µmol l-1 -
PO4_FLAG_W - Phosphate flags - - -
oxy_cal µmol l-1 CTD oxygen - - -
oxy_cal_FLAG_W - CTD oxygen flags - - -
NO3 µmol kg-1 Nitrate+nitrite - - Nitrate+nitrite in µmol l-1 units loaded
NO3_FLAG_W - Nitrate+nitrite flags - - -
SiO4 µmol kg-1 Silicate - - Silicate in µmol l-1 units loaded
SiO4_FLAG_W - Silicate flags - - -
PO4 µmol kg-1 Phosphate - - Phosphate in µmol l-1 units loaded
PO4_FLAG_W - Phosphate flags - - -

Data Quality Report

None (BODC assessment).

Problem Report

None (BODC assessment).

Project Information

Antarctic Deep Water Rates of Export (ANDREX) project document

ANDREX is a UK field programme aimed at investigating the role of the Weddell Gyre in the Meridional Overturning Circulation (MOC) and its influence on deep ocean properties.

The MOC is a critical regulator of Earth's climate and is crucial for deep water ventilation across the globe. Surface currents transport waters towards the poles, where they become dense and sink, flowing equatorward as deep, cool currents. The MOC ensures that the deep oceans remain ventilated and conducive to life, and is also important for anthropogenic carbon sequestration. The southern closure of the MOC in the Weddell Sea is strongly influenced by the Weddell Gyre, which facilitates the exchange of waters between the Antarctic Circumpolar Current (ACC) and the waters of the continental shelf. Cooling and sea ice formation in the Weddell Sea lead to overturning of the water column and the ventilation of Antarctic Bottom Water (AABW), which flows out of the Weddell Sea and into the deep oceans to the north. Thus, the Weddell Gyre plays an important role in the properties of deep ocean waters on a global scale.

The goals of ANDREX are to investigate the exchange of water masses between the ACC and the Weddell Sea, including AABW formation and ventilation rates, carbon and nutrient cycling, the influence of fresh water input from sea ice, precipitation and glacial melt, and the role of the Weddell Gyre in anthropogenic carbon sequestration. The project includes hydrographic, ventilation tracer, biogeochemical and bathymetric measurements along the outer rim of the Weddell Gyre.

ANDREX is funded by the UK Natural Environment Research Council (NERC) Antarctic Funding Initiative (AFI) and involves scientists from the National Oceanography Centre, Southampton (NOC), the British Antarctic Survey (BAS), the University of East Anglia (UEA), the University of Manchester, the Alfred Wegener Institut (AWI) and the Woods Hole Oceanographic Institution (WHOI).

For more information please see the official project website at ANDREX

Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2009-01-13
End Date (yyyy-mm-dd) 2009-01-13
Organization Undertaking ActivityNational Oceanography Centre, Southampton
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierJC030_CTD_CTD26
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for JC030_CTD_CTD26

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
233829   20.00 8 8 3563.30 3564.00 3500.30 Niskin bottle No problem reported    
233830   20.00 9 9 3050.50 3051.00 3000.00 Niskin bottle No problem reported    
233831   20.00 10 10 2540.10 2541.40 2501.60 Niskin bottle No problem reported    
233832   20.00 11 11 2029.70 2031.00 2001.60 Niskin bottle No problem reported    
233833   20.00 12 12 1519.50 1519.90 1499.80 Niskin bottle No problem reported    
233834   20.00 13 13 1011.60 1012.30  999.90 Niskin bottle No problem reported    
233835   20.00 14 14  809.30  809.80  800.30 Niskin bottle Bottle leak   Bottle leaked
233836   20.00 15 15  607.40  608.90  601.70 Niskin bottle No problem reported    
233837   20.00 16 16  405.10  405.90  401.30 Niskin bottle No problem reported    
233838   20.00 17 17  304.70  305.30  302.00 Niskin bottle No problem reported    
233839   20.00 18 18  202.30  204.00  201.00 Niskin bottle No problem reported    
233840   20.00 19 19  153.50  153.80  152.20 Niskin bottle No problem reported    
233841   20.00 20 20  103.40  104.10  102.60 Niskin bottle No problem reported    
233842   20.00 21 21   77.80   78.30   77.30 Niskin bottle Bottle leak   Bottle leaked
233843   20.00 22 22   51.80   52.10   51.40 Niskin bottle No problem reported    
233844   20.00 23 23   26.50   26.90   26.40 Niskin bottle Bottle leak   Bottle did not seal
233845   20.00 24 24    7.60    8.20    7.80 Niskin bottle Bottle leak   Bottle leaked
233919   20.00 1 1 5577.60 5578.90 5454.30 Niskin bottle No problem reported    
233920   20.00 2 2 5528.10 5530.30 5407.20 Niskin bottle No problem reported    
233921   20.00 3 3 5474.50 5475.80 5354.70 Niskin bottle No problem reported    
233922   20.00 4 4 5371.20 5372.00 5254.70 Niskin bottle No problem reported    
233923   20.00 5 5 5112.60 5113.30 5004.60 Niskin bottle Bottle leak   Bottle leaked
233924   20.00 6 6 4594.70 4595.00 4502.70 Niskin bottle No problem reported    
233925   20.00 7 7 4075.80 4077.00 3999.10 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 JC030
Departure Date 2008-12-26
Arrival Date 2009-01-30
Principal Scientist(s)Sheldon Bacon (National Oceanography Centre, Southampton)
Ship RRS James Cook

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