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Metadata Report for BODC Series Reference Number 1621174


Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
NameCategories
Niskin bottle  discrete water samplers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Mr Tim Brand
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 D340A_CTD_NUTS_304:C042
BODC Series Reference 1621174
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2009-06-20 12:24
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 57.10412 N ( 57° 6.2' N )
Longitude 9.42997 W ( 9° 25.8' W )
Positional Uncertainty Unspecified
Minimum Sensor or Sampling Depth 7.1 m
Maximum Sensor or Sampling Depth 1486.7 m
Minimum Sensor or Sampling Height -0.7 m
Maximum Sensor or Sampling Height 1478.9 m
Sea Floor Depth 1486.0 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
 

Parameters

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)
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
SDAMAATX1Micromoles per litreConcentration standard deviation of ammonium {NH4+ CAS 14798-03-9} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
SDNZAATX1Micromoles per litreConcentration standard deviation of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
SDPHAATX1Micromoles per litreConcentration standard deviation of phosphate {PO43- CAS 14265-44-2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
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
SLSDAATX1Micromoles per litreConcentration standard deviation 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

BOTTFLAGDefinition
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.

Deployment

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.

D340A Discrete Dissolved Inorganic Nutrients Sampling Document

Originator's Protocol for Data Acquisition and Analysis

Water samples were drawn from the CTD rosette bottles deployed during the cruise with the majority of the sampling effort concentrated in areas of the water column corresponding with changes in water mass and changes in algal mass.

Samples were collected in 250 ml acid cleaned polythene bottles directly from CTD spigots without the use of a tube. Samples were stored in a fridge prior to analysis. The analysis was carried out within 24 hours of sample collection with a Lachat Quick Chem 8500 flow injection autoanalyser using the manufacturer's recommended methods. Standards were prepared in deionised water and samples were run in a carrier stream of deionised water.

Salt corrections were performed by running a small number of Low Nutrient Sea Water samples during each sample batch run with the mean result being subtracted from sample results.

References Cited

Sherwin T. A. et al., 2009. Cruise D340A Reykjavic to Dunstaffnage via Rockall and the Wyville Thomson Ridge. Internal Report No 264. Scottish Association for Marine Science.

Available - Cruise D430A Internal Report

BODC Data Processing Procedures

The nutrient data were supplied to BODC in Microsoft Excel format. Values were extracted from these and saved in ASCII format prior to being loaded into BODC's ocean database under the ORACLE Relational Database Management System. Data that were considered unrealistic were flagged suspect.

SAMS nitrate data quality warning

SAMS have notified BODC of a problem in the analytical procedure adopted for nitrate analysis on this cruise. The problem relates to the technique used to prepare the analytical standards, which results in nitrate (and consequently nitrite) values which are typically 10-15 % higher than they should be. Absolute data values should therefore be used with extreme caution.

Content of data series

Originator's Parameter Originator's Unit Description BODC's Parameter Code BODC's Unit Comments
Ammonium µM Concentration of ammonium in the water column by colorimetric autoanalysis (unfiltered) AMONAATX µM n/a
Standard deviation of ammonium µM Concentration standard deviation of ammonium in the water column by colorimetric autoanalysis (unfiltered) SDAMAATX µM n/a
Phosphate µM Concentration of phosphate in the water column by colorimetric autoanalysis (unfiltered) PHOSAATX µM n/a
Standard deviation of phosphate µM Concentration standard deviation of phosphate in the water column by colorimetric autoanalysis (unfiltered) SDPHAATX µM n/a
Silicate µM Concentration of silicate in the water column by colorimetric autoanalysis (unfiltered) SLCAAATX µM n/a
Standard deviation of silicate µM Concentration standard deviation of silicate in the water column by colorimetric autoanalysis (unfiltered) SLSDAATX µM n/a
Nitrate and nitrite µM Concentration of nitrate and nitrite in the water column by colorimetric autoanalysis (unfiltered) NTRZAATX µM n/a
Standard deviation of nitrate and nitrite µM Concentration standard deviation of nitrate and nitrite in the water column by colorimetric autoanalysis (unfiltered) SDNZAATX µM n/a

Data Quality Report

A number of the values in the channels AMONAATX and SDAMAATX have negative values which have subsequently been flagged.


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

Weblink: http://www.oceans2025.org/


Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2009-06-20
End Date (yyyy-mm-dd) 2009-06-20
Organization Undertaking ActivityScottish Association for Marine Science
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierD340A_CTD_C042
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for D340A_CTD_C042

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
221994   1 1 1505.80 1506.00 1486.70 Niskin bottle No problem reported    
221995   2 2 1505.50 1506.30 1486.70 Niskin bottle No problem reported    
221996   3 3 1215.30 1216.10 1201.00 Niskin bottle No problem reported    
221997   4 4 1214.90 1215.60 1200.60 Niskin bottle No problem reported    
221998   5 5 1214.70 1215.10 1200.20 Niskin bottle No problem reported    
221999   6 6 1012.80 1013.20 1001.20 Niskin bottle No problem reported    
222000   7 7 1012.60 1012.80 1001.00 Niskin bottle No problem reported    
222001   8 8 1012.00 1013.60 1001.00 Niskin bottle No problem reported    
222002   9 9  811.50  812.00  802.70 Niskin bottle No problem reported    
222003   10 10  811.20  811.80  802.50 Niskin bottle No problem reported    
222004   11 11  507.60  508.60  502.80 Niskin bottle No problem reported    
222005   12 12  507.70  508.40  502.80 Niskin bottle No problem reported    
222006   13 13  306.20  306.60  303.40 Niskin bottle No problem reported    
222007   14 14  306.30  307.10  303.70 Niskin bottle Bottle leak    
222008   15 15  155.00  155.30  153.70 Niskin bottle No problem reported    
222009   16 16  155.20  155.50  153.90 Niskin bottle No problem reported    
222010   17 17  104.00  104.10  103.10 Niskin bottle No problem reported    
222011   18 18  104.00  104.20  103.10 Niskin bottle No problem reported    
222012   19 19   53.30   53.50   52.90 Niskin bottle No problem reported    
222013   20 20   53.00   53.30   52.70 Niskin bottle No problem reported    
222014   21 21   27.70   27.90   27.50 Niskin bottle No problem reported    
222015   22 22   27.60   28.10   27.60 Niskin bottle No problem reported    
222016   23 23    7.40    7.60    7.40 Niskin bottle No problem reported    
222017   24 24    6.90    7.40    7.10 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

Cruise Name D340A
Departure Date 2009-06-10
Arrival Date 2009-06-25
Principal Scientist(s)Toby J Sherwin (Scottish Association for Marine Science)
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
Q value below limit of quantification