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Metadata Report for BODC Series Reference Number 1339930


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) -
 

Data Identifiers

Originator's Identifier D379_CTD_NUTS_304:C104
BODC Series Reference 1339930
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2012-08-14 21:43
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 62.66780 N ( 62° 40.1' N )
Longitude 19.66590 W ( 19° 40.0' W )
Positional Uncertainty Unspecified
Minimum Sensor or Sampling Depth 5.6 m
Maximum Sensor or Sampling Depth 1666.6 m
Minimum Sensor or Sampling Height 20.4 m
Maximum Sensor or Sampling Height 1681.4 m
Sea Floor Depth 1687.0 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
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
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.

D379 discrete dissolved inorganic nutrients sampling document

Originator's protocol for data acquisition and analysis

Water samples were drawn from CTD rosette bottles fired during the cruise for inorganic nutrient analysis. Ammonia, phosphate, silicate and nitrate+nitrite were targeted, with the majority of the sampling effort concentrated in areas of the water column corresponding with changes in water mass. 49 samples were also drawn from the ship's non-toxic water supply. Due to a faulty rotary valve the phosphate line stopped working during the cruise. As it was considered more important to measure phosphate rather than ammonia, the ammonia line rotary valve was swapped for the defective phosphate one.

Samples were collected in 125 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.

Samples were measured in triplicate to identify instrument precision. A stock-mixed standard was prepared in deionized water with subsequent dilutions made in OSIL Low Nutrient Sea Water using the instrument auto-dilutor facility. Five standard concentrations and a blank were run in all cases and new standards were prepared every 48 hours. Using standards prepared in Low Nutrient Sea Water removes the need to do a separate salt correction. Three standard concentration ranges were prepared for the non-toxic samples and those collected across the Wyville Thomson CTD transect, depending on expected nutrient concentration.

BODC data processing procedures

The nutrient data were supplied to BODC in Microsoft Excel format. Values were extracted from this file and loaded into BODC's ORACLE relational database. Standard deviatons were calculated by the Originator. Data that were considered unrealistic were flagged suspect. Metadata collected from the various data files were favoured by BODC over the metadata recorded in the cruise report logs present in the D379 cruise report.

Content of data series

Originator's Parameter Unit Description BODC Parameter code BODC Unit Comments
CTD bottle ammonium µM Concentration of ammonium in the water column by colorimetric autoanalysis (unfiltered) AMONAATX µM N/A
Standard deviation of CTD bottle ammonium µM Concentration standard deviation of ammonium in the water column by colorimetric autoanalysis (unfiltered) SDAMAATX µM N/A
CTD bottle and discrete underway phosphate µM Concentration of phosphate in the water column by colorimetric autoanalysis (unfiltered) PHOSAATX µM N/A
Standard deviation of CTD bottle and discrete underway phosphate µM Concentration standard deviation of phosphate in the water column by colorimetric autoanalysis (unfiltered) SDPHAATX µM N/A
CTD bottle and discrete underway silicate µM Concentration of silicate in the water column by colorimetric autoanalysis (unfiltered) SLCAAATX µM N/A
Standard deviation of CTD bottle and discrete underway silicate µM Concentration standard deviation of silicate in the water column by colorimetric autoanalysis (unfiltered) SLSDAATX µM N/A
CTD bottle and discrete underway nitrate/ nitrite µM Concentration of nitrate and nitrite in the water column by colorimetric autoanalysis (unfiltered) NTRZAATX µM N/A
Standard deviation of CTD bottle and discrete underway nitrate/ nitrite µM Concentration standard deviation of nitrate and nitrite in the water column by colorimetric autoanalysis (unfiltered) SDNZAATX µM N/A

Data quality report

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

It has been noted, however, that the silicate value for the NUT008 sample was below the detection limit. This was conveyed by a low instrument signal. The user should be aware of this when using these data.

Two silicate values (sampled on CTD cast 98 and 102) and one nitrate/ nitrite value (sampled on CTD cast 18) were negative. These values have been assigned an 'M' flag by BODC.

References cited

Griffiths C. R. et al., (2012). RRS Discovery Cruise D379, 31 Jul 2012 - 17 Aug 2012. Southampton to Reykjavic - the Extended Ellett Line. Scottish Association for Marine Science, 184pp. (Scottish Marine Institute, Oban.)

Available - Cruise D379 Internal Report


Project Information


No Project Information held for the Series

Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2012-08-14
End Date (yyyy-mm-dd) 2012-08-14
Organization Undertaking ActivityScottish Association for Marine Science
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierD379_CTD_C104
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for D379_CTD_C104

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
904928   10.00 1 1 1689.20 1689.50 1666.30 Niskin bottle No problem reported    
904931   10.00 2 2 1689.30 1690.20 1666.60 Niskin bottle No problem reported    
904934   10.00 3 3 1623.60 1624.30 1602.00 Niskin bottle No problem reported    
904937   10.00 4 4 1470.70 1471.10 1451.60 Niskin bottle No problem reported    
904940   10.00 5 5 1318.90 1319.10 1302.10 Niskin bottle No problem reported    
904943   10.00 6 6 1216.70 1217.50 1201.80 Niskin bottle No problem reported    
904946   10.00 7 7 1014.70 1015.30 1002.80 Niskin bottle No problem reported    
904949   10.00 8 8  913.10  913.50  902.50 Niskin bottle No problem reported    
904952   10.00 9 9  760.70  761.70  752.50 Niskin bottle No problem reported    
904955   10.00 10 10  608.90  609.70  602.40 Niskin bottle No problem reported    
904958   10.00 11 11  508.10  508.40  502.70 Niskin bottle No problem reported    
904961   10.00 12 12  508.00  509.00  502.90 Niskin bottle No problem reported    
904964   10.00 13 13  406.70  407.40  402.70 Niskin bottle No problem reported    
904967   10.00 14 14  205.10  205.90  203.50 Niskin bottle No problem reported    
904970   10.00 15 15  104.50  104.80  103.60 Niskin bottle No problem reported    
904973   10.00 16 16  104.40  104.80  103.50 Niskin bottle No problem reported    
904976   10.00 17 17   74.00   74.60   73.60 Niskin bottle No problem reported    
904979   10.00 18 18   73.80   74.30   73.30 Niskin bottle No problem reported    
904982   10.00 19 19   48.90   49.30   48.50 Niskin bottle No problem reported    
904985   10.00 20 20   48.70   49.00   48.30 Niskin bottle No problem reported    
904988   10.00 21 21   18.50   18.80   18.40 Niskin bottle No problem reported    
904991   10.00 22 22   18.40   19.00   18.50 Niskin bottle No problem reported    
904994   10.00 23 23    5.60    6.40    6.00 Niskin bottle No problem reported    
904997   10.00 24 24    5.50    5.80    5.60 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.

Cruise

Cruise Name D379
Departure Date 2012-07-30
Arrival Date 2012-08-17
Principal Scientist(s)Colin R Griffiths (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