Metadata Report for BODC Series Reference Number 1350010


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 Prof Richard Sanders
Originating Organization National Oceanography Centre, Southampton
Processing Status banked
Project(s) -
 

Data Identifiers

Originator's Identifier D312_CTD_NUTS_208:16127
BODC Series Reference 1350010
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2006-10-12 19:13
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 63.22166 N ( 63° 13.3' N )
Longitude 20.06005 W ( 20° 3.6' W )
Positional Uncertainty Unspecified
Minimum Sensor Depth 7.3 m
Maximum Sensor Depth 628.0 m
Minimum Sensor Height -34.7 m
Maximum Sensor Height 586.0 m
Sea Floor Depth 593.3 m
Sensor Distribution Unspecified -
Sensor Depth Datum Unspecified -
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODE Rank Units Short Title Title
ADEPZZ01 1 Metres DepBelowSurf Depth below surface of the water body
BOTTFLAG 1 Dimensionless C22_flag Sampling process quality flag (BODC C22)
FIRSEQID 1 Dimensionless FireSeqNo Bottle firing sequence number
NTRZAATX 1 Micromoles per litre NO3+NO2_Unfilt_ColAA Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
PHOSAATX 1 Micromoles per litre PO4_Unfilt_ColAA Concentration of phosphate {PO43- CAS 14265-44-2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
SAMPRFNM 1 Dimensionless SampRef Sample reference number
SLCAAATX 1 Micromoles per litre SiOx_Unfilt_ColAA Concentration of silicate {SiO44- CAS 17181-37-2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
 

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.

Extended Ellett Line Inorganic Nutrient Data for RRS Discovery cruise D312

Originator's Data Acquisition and Analysis

Inorganic nutrients were measured on every bottle from every CTD cast following Sanders and Jickells (2000) using a Skalar San Plus autoanalyser equipped equipped with an all glass phosphate line. All data was processed in flow access version 1.04.4. In total 634 niskin bottle were analysed. Samples were drawn directly from niskin bottles into 25 ml sterilin polystyrene coulter counter vials, refrigerated in the dark at 4°C and analysed within 24 hours. Overall seventeen runs were carried out.

The instrument did not perform well on this trip despite the usual precautions being taken (washing the lines with 10 % Decon (N, Si) or Sodium Hydroxide (P), changing the tubes). Despite the various problems encountered all samples were analysed satisfactorily with the exception of phosphate from station 152.

BODC processing

The data were received in 64 pstar files which were loaded into the BODC database using established BODC data banking procedures without any changes.

The mapping between the originator's channels and BODC parameter codes is detailed in the table below.

Originator's Parameter Unit Description BODC Parameter Code BODC Unit Comments
NO3+NO2 Micromoles per litre Concentration of Nitrate + Nitrite {NO3+NO2} NTRZAATX Micromoles per litre n/a
PO4 Micromoles per litre Concentration of Phosphate {PO4} PHOSAATX Micromoles per litre n/a
SiO4 Micromoles per litre Concentration of Silicate SLCAAATX Micromoles per litre n/a

Data Quality Report

For a detailed QC analysis please see ( Cruise Report ) page 106.


Project Information


No Project Information held for the Series

Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2006-10-12
End Date (yyyy-mm-dd) 2006-10-12
Organization Undertaking ActivityNational Oceanography Centre, Southampton
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierD312_CTD_16127
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for D312_CTD_16127

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
185216   10.00   1  634.60  635.60  628.00 Niskin bottle No problem reported    
185217   10.00   2  607.90  608.90  601.60 Niskin bottle No problem reported    
185218   10.00   3  502.20  503.20  497.20 Niskin bottle No problem reported    
185219   10.00   4  450.80  451.80  446.40 Niskin bottle No problem reported    
185220   10.00   5  404.60  405.60  400.80 Niskin bottle No problem reported    
185221   10.00   6  354.40  355.40  351.20 Niskin bottle No problem reported    
185222   10.00   7  305.20  306.20  302.50 Niskin bottle No problem reported    
185223   10.00   8  255.40  256.40  253.30 Niskin bottle No problem reported    
185224   10.00   9  204.50  205.50  202.90 Niskin bottle No problem reported    
185225   10.00   10  133.90  134.90  133.10 Niskin bottle No problem reported    
185226   10.00   11   72.80   73.80   72.60 Niskin bottle No problem reported    
185227   10.00   12   52.50   53.50   52.50 Niskin bottle No problem reported    
185228   10.00   13    6.90    7.90    7.30 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 D312
Departure Date 2006-10-11
Arrival Date 2006-10-31
Principal Scientist(s)John T Allen (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