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Metadata Report for BODC Series Reference Number 1342126

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 Miss Estelle Dumont
Originating Organization Scottish Association for Marine Science
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) Oceans 2025 Theme 10 SO4

Data Identifiers

Originator's Identifier D365_CTD_NUTS_897:CTD54_R
BODC Series Reference 1342126

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2011-05-31 16:17
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -

Spatial Co-ordinates

Latitude 57.00117 N ( 57° 0.1' N )
Longitude 8.98866 W ( 8° 59.3' W )
Positional Uncertainty Unspecified
Minimum Sensor or Sampling Depth 5.5 m
Maximum Sensor or Sampling Depth 123.7 m
Minimum Sensor or Sampling Height 7.4 m
Maximum Sensor or Sampling Height 125.6 m
Sea Floor Depth 131.1 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
AMONAATX1Micromoles per litreConcentration of ammonium {NH4+ CAS 14798-03-9} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
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
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.

D365 RRS Discovery Cruise discrete inorganic nutrients sampling document

Cruise details

Dates 2011-05-11 - 2011-06-02
Principal Scientific Officer Jane Read (National Oceanography Centre, Southampton)
Data Originator Estelle Dumont (Scottish Association for Marine Science)

The Extended Ellett Line is a full-depth hydrographic section between Iceland, 60°N 20°W, Rockall and Scotland. The original Ellett Line across the Rockall Trough was first occupied in 1975 when measurements were attempted four times a year. In 1996 the line was extended to Iceland and since then has been occupied approximately annually. The data form a 35 year time series of the oceanic conditions west of the British Isles. The section monitors the characteristics of the warm water inflow into the Nordic Seas and thence to the Arctic, and observes part of the returning cold water outflow with measurements of the Iceland-Scotland Overflow and the overflow of the Wyville-Thomson Ridge into the Rockall Trough. In total 55 CTD casts were completed during the cruise along the original and Extended Ellett Line, with nutrient samples being taken from the majority of bottles fired on the upcasts.

Originator's data acquisition and processing

The basic water column dissolved nutrients, ammonia, phosphate, silicate (reactive silica) and total oxidized nitrogen (nitrite + nitrate) were analyzed from CTD casts along the Extended Ellett Line. CTD depths for the samples were chosen to correspond with those of the chlorophyll and algal cell count studies down to 200 m and at depths below this corresponding with CFC gas studies. Additional other depths were sometimes chosen to coincide with changes in water mass identified by the TS and dissolved oxygen characteristics from the CTD casts.

Samples were collected in 125 ml acid cleaned polythene bottles directly from the CTD spigots without the use of a tube. Samples were always analyzed within 24 hours of collection and stored in a fridge prior to analysis. Measurement was conducted using a Lachat QuikChem 8500 flow injection autoanalyser using the manufacturers recommended methods: Ammonia, 31-107-06-1-B; Orthophosphate, 31-115-01-1-G; Silicate, 31-114-27-1-A and Nitrate/Nitrite, 31-107-04-1-A.
Samples were measured in triplicate to identify instrument precision. Standards were prepared in deionised water and the samples and standards run in a carrier stream of deionised water. A standard reference solution prepared from nutrient standard solutions supplied by OSIL containing 1µMNH4, 1µMPO4, 10µMSiO2 and 10µMNO3 was run at the start and end of each sample batch to determine analytical accuracy and to adjust for calibration drift during the course of a sample batch analysis.

BODC data processing procedures

Data arrived at BODC in a Microsoft Excel spreadsheet containing 1109 nutrient samples taken during the cruise. The spreadsheet was initially converted into a Comma Separated Values format file (.csv) and appropriate BODC parameter codes were subsequently assigned. The following table shows how the variables supplied were mapped to BODC parameter codes.

Please note: 1109 CTD OTE bottles were fired during 55 CTD casts taken on cruise D365. However, not all of these bottle firings resulted in nutrient samples being taken and/or analysed to produce valid measurements.

Content of data series

Originator's Parameter Originator's Units Parameter description BODC Parameter code BODC Units Comments
Nitrate µM Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis NTRZAATX µmol l-1 Nitrate=nitrate+nitrite
Silicate µM Concentration of silicate {SiO4} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis SLCAAATX µmol l-1  
Phosphate µM Concentration of phosphate {PO4} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis PHOSAATX µmol l-1  
Ammonia µM Concentration of ammonium {NH4} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis AMONAATX µmol l-1  

The data were loaded from the .csv file into an Oracle database where measurements were linked to corresponding depths through the CTD rosette bottle no. (supplied by the originator) and the CTD rosette bottle no. obtained from electronic Seabird CTD logs (which contained accurate pressure readings for each bottle fired).

Data that lay outside the permitted range for the parameter code were flagged suspect with an 'M' flag by BODC.

Data Quality Report

No problems reported and no significant issues encountered during BODC banking procedures.

Problem Report

No problems reported and no significant issues encountered during BODC banking procedures.


Further information can be found in the cruise report cruise report

Project Information

Oceans 2025 Theme 10, Sustained Observation Activity 4: The Extended Ellett Line

The Ellett Line (begun in 1975 and since 1996 the Extended Ellett Line from Scotland to Iceland) crosses important north Atlantic Meridional Overturning Circulation (MOC) components and thus provides an additional contribution to understanding the north Atlantic response to climate change. Sustained Observation Activity (SO) 4 will repeat this section annually collecting a wide variety of physical and biogeochemical measurements, and will, to enhance the time variable component, make use of Argo floats and gliders. SO 4 will be implemented by physical, biological and chemical scientists at the National Oceanography Centre, Southampton (NOCS) and the Scottish Association for Marine Science (SAMS).

SO 4 formally contributes to the Department for Environment, Food and Rural Affairs (DEFRA)-funded Marine Environmental Change Network (MECN). Established in 2002 to coordinate and promote the collection and utilisation of marine time-series and long-term data sets, the goal of the network is to use long-term marine environmental data from around the British Isles and Ireland to separate natural fluctuations from global, regional and local anthropogenic impacts.

The specific deliverables for SO 4 are:

  • A time series of the evolution of the hydrography of the northeast Atlantic, together with a more formal understanding of the causes of any changes observed
  • An archived data set available to the international community via the British Oceanographic Data Centre (BODC)
  • A platform for further scientific research

More detailed information on this Work Package is available at pages 15 - 16 of the official Oceans 2025 Theme 10 document: Oceans 2025 Theme 10


Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2011-05-31
End Date (yyyy-mm-dd) 2011-05-31
Organization Undertaking ActivityNational Oceanography Centre, Southampton
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierD365_CTD_CTD54_R
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for D365_CTD_CTD54_R

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
768881 10.00 1    124.20  125.20  123.50 Niskin bottle No problem reported    
768884 10.00 2    124.40  125.40  123.70 Niskin bottle No problem reported    
768887 10.00 3     82.00   83.00   81.70 Niskin bottle No problem reported    
768890 10.00 4     81.70   82.70   81.40 Niskin bottle No problem reported    
768893 10.00 5     61.80   62.80   61.70 Niskin bottle No problem reported    
768896 10.00 6     62.00   63.00   61.90 Niskin bottle No problem reported    
768899 10.00 7     39.80   40.80   39.90 Niskin bottle No problem reported    
768902 10.00 8     39.70   40.70   39.80 Niskin bottle No problem reported    
768905 10.00 9     20.30   21.30   20.60 Niskin bottle No problem reported    
768908 10.00 10     20.30   21.30   20.60 Niskin bottle No problem reported    
768911 10.00 11     10.10   11.10   10.50 Niskin bottle No problem reported    
768914 10.00 12     10.10   11.10   10.50 Niskin bottle No problem reported    
768917 10.00 13      5.00    6.00    5.40 Niskin bottle No problem reported    
768920 10.00 14      5.10    6.10    5.50 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 D365
Departure Date 2011-05-11
Arrival Date 2011-06-02
Principal Scientist(s)Jane F Read (National Oceanography Centre, Southampton)
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