Metadata Report for BODC Series Reference Number 1115949


Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
NameCategories
Niskin bottle  discrete water samplers
SPX Bran+Luebbe colorimetric Autoanalyser 3  colorimeters; autoanalysers
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Mrs Carolyn Harris
Originating Organization Plymouth Marine Laboratory
Processing Status QC in progress
Project(s) Oceans 2025 Theme 10 SO1:AMT
 

Data Identifiers

Originator's Identifier JC053_CTD_CTD07s_Harris_nuts
BODC Series Reference 1115949
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2010-10-15 13:32
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 48.11781 N ( 48° 7.1' N )
Longitude 17.32521 W ( 17° 19.5' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth 1.5 m
Maximum Sensor Depth 299.7 m
Minimum Sensor Height 4110.3 m
Maximum Sensor Height 4408.5 m
Sea Floor Depth 4410.0 m
Sensor Distribution Variable common depth - All sensors are grouped effectively at the same depth, but this depth varies significantly during the series
Sensor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
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
NTRIAATX 1 Micromoles per litre NO2_Unfilt_ColAA Concentration of nitrite {NO2- CAS 14797-65-0} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
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
ROSPOSID 1 Dimensionless RosPos Bottle rosette position identifier
SAMPRFNM 1 Dimensionless SampRef Sample reference number
 

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 Quality Report - see processing documentation

Data quality information is included in the general documentation for this series. Please read.


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

SPX Bran+Luebbe Autoanalyser 3

The instrument uses continuous flow analysis (CFA) with a continuous stream of material divided by air bubbles into discrete segments in which chemical reactions occur. The continuous stream of liquid samples and reagents are combined and transported in tubing and mixing coils. The tubing passes the samples from one apparatus to the other with each apparatus performing different functions, such as distillation, dialysis, extraction, ion exchange, heating, incubation, and subsequent recording of a signal.

An essential principle of the system is the introduction of air bubbles. The air bubbles segment each sample into discrete packets and act as a barrier between packets to prevent cross contamination as they travel down the length of the tubing. The air bubbles also assist mixing by creating turbulent flow (bolus flow), and provide operators with a quick and easy check of the flow characteristics of the liquid.

Samples and standards are treated in an exactly identical manner as they travel the length of the tubing, eliminating the necessity of a steady state signal, however, since the presence of bubbles create an almost square wave profile, bringing the system to steady state does not significantly decrease throughput and is desirable in that steady state signals (chemical equilibrium) are more accurate and reproducible.

The autoanalyzer can consist of different modules including a sampler, pump, mixing coils, optional sample treatments (dialysis, distillation, heating, etc), a detector, and data generator. Most continuous flow analyzers depend on color reactions using a flow through colorimeter, however other methods have been developed that use ISE, flame photometry, ICAP, fluorometry, and so forth.

More details can be found in the manufacturer's introduction to autoanalysers and instrument description .

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.

AMT20 (JC053) Micro-molar nutrient measurements from CTD bottle samples

Originator's Protocol for Data Acquisition and Analysis

Water samples were taken from the Sea-Bird CTD rosette system. They were sub-sampled into acid-clean 60 ml HDPE (nalgene) sample bottles. Analysis for nutrients was completed within 1-2 hours of sampling in all cases. Clean handling techniques were employed to avoid contamination of the samples.

The main nutrient analyser was a 5-channel Bran and Luebbe AAIII segmented flow autoanalyser. The analytical chemical methodologies used were according to Brewer and Riley (1965) for nitrate, Grasshoff (1976) for nitrite and Kirkwood (1989) for phosphate and silicate.

References Cited

Brewer P.G. and Riley J.P., 1965. The automatic determination of nitrate in sea water. Deep-Sea Research, 12, 765-772.

Grasshoff K., 1976. Methods of seawater analysis. Verlag Chemie, Weiheim: 317 pp.

Kirkwood D.S., 1989. Simultaneous determination of selected nutrients in seawater. ICES CM1989/C:29, 12pp.

Instrumentation Description

5-channel Bran and Luebbe AAIII segmented flow autoanalyser

BODC Data Processing Procedures

Data were submitted to BODC in Microsoft Excel spreadsheet format and saved to the BODC archive with reference PML120103. Sample metadata provided (Cast number and sample depth) were checked against information held in the database, there was one discrepancy. Cast 40 had a depth of 15 m provided but no bottle was fired at this depth for this cast. The sample was loaded against a depth of 20 m instead.

No unit conversions were necessary as the units provided matched the units for the parameter codes in the BODC Parameter Dictionary. The dataset was loaded to the database following BODC protocols.

A parameter mapping table is provided below;

Originator's Parameter Units Description BODC Parameter Code Units Comments
Nitrate+Nitrite (AAIII) µmol l -1 Concentration of nitrate+nitrite {NO 3 +NO 2 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis NTRZAATX µmol l -1 -
Nitrite (AAIII) µmol l -1 Concentration of nitrite {NO 2 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis NTRIAATX µmol l -1 -
Phosphate (AAIII) µmol l -1 Concentration of phosphate {PO 4 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis PHOSAATX µmol l -1 -
Silicate (AAIII) µmol l -1 Concentration of silicate {SiO 4 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis SLCAAATX µmol l -1 -

Data Quality Report

Data provided were quality checked by the originator and flagged accordingly. The silicate data for many of the samples were considered suspect by the originator and not submitted to BODC for this reason.

Measurement precision information from data originators: Samples in the database with a flag of "<" had concentrations below the specified detection limits.

Problem Report

Not applicable for this dataset.


Project Information

Oceans 2025 Theme 10, Sustained Observation Activity 1: The Atlantic Meridional Transect (AMT)

The Atlantic Meridional Transect has been operational since 1995 and through the Oceans 2025 programme secures funding for a further five cruises during the period 2007-2012. The AMT programme began in 1995 utilising the passage of the RRS James Clark Ross between the UK and the Falkland Islands southwards in September and northwards in April each year. Prior to Oceans 2025 the AMT programme has completed 18 cruises following this transect in the Atlantic Ocean. This sustained observing system aims to provide basin-scale understanding of the distribution of planktonic communities, their nutrient turnover and biogenic export in the context of hydrographic and biogeochemical provinces of the North and South Atlantic Oceans.

The Atlantic Meridional Transect Programme is an open ocean in situ observing system that will:

The specific objectives are:

The measurements taken and experiments carried out on the AMT cruises will be closely linked to Themes 2 and 5. The planned cruise track also allows for the AMT data to be used in providing spatial context to the Sustained Observation Activities at the Porcupine Abyssal Plain Ocean Observatory (SO2) and the Western Channel Observatory (SO10).

More detailed information on this Work Package is available at pages 6 - 9 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) 2010-10-15
End Date (yyyy-mm-dd) 2010-10-15
Organization Undertaking ActivityPlymouth Marine Laboratory
Country of OrganizationGermany
Originator's Data Activity IdentifierJC053_CTD_CTD07s
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for JC053_CTD_CTD07s

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
234287   20.00 1 1  302.00  302.90  299.70 Niskin bottle No problem reported    
234288   20.00 2 2  201.60  202.30  200.20 Niskin bottle No problem reported    
234289   20.00 3 3  100.90  101.70  100.40 Niskin bottle No problem reported    
234290   20.00 4 4   75.90   76.40   75.50 Niskin bottle No problem reported    
234291   20.00 5 5   51.10   51.80   51.00 Niskin bottle No problem reported    
234292   20.00 6 6   51.30   51.70   51.10 Niskin bottle No problem reported    
234293   20.00 7 7   51.30   51.60   51.00 Niskin bottle No problem reported    
234294   20.00 8 8   51.00   51.90   51.00 Niskin bottle No problem reported    
234295   20.00 9 9   40.70   40.90   40.50 Niskin bottle No problem reported    
234296   20.00 10 10   35.80   36.10   35.60 Niskin bottle No problem reported    
234297   20.00 11 11   20.70   21.50   20.90 Niskin bottle No problem reported    
234298   20.00 12 12   20.60   21.60   20.90 Niskin bottle No problem reported    
234299   20.00 13 13   20.90   21.20   20.90 Niskin bottle No problem reported    
234300   20.00 14 14   20.80   21.40   20.90 Niskin bottle No problem reported    
234301   20.00 15 15   10.50   11.00   10.70 Niskin bottle No problem reported    
234302   20.00 16 16   10.70   10.90   10.70 Niskin bottle No problem reported    
234303   20.00 17 17   10.70   11.10   10.80 Niskin bottle No problem reported    
234304   20.00 18 18    5.60    6.00    5.80 Niskin bottle No problem reported    
234305   20.00 19 19    5.60    6.20    5.90 Niskin bottle No problem reported    
234306   20.00 20 20    1.40    2.10    1.70 Niskin bottle No problem reported    
234307   20.00 21 21    1.40    1.90    1.60 Niskin bottle No problem reported    
234308   20.00 22 22    1.20    2.20    1.70 Niskin bottle No problem reported    
234309   20.00 23 23    1.30    2.00    1.60 Niskin bottle No problem reported    
234310   20.00 24 24    1.00    2.10    1.50 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.

Other Series linked to this Data Activity - 1629416

Cruise

Cruise Name JC053 (AMT20)
Departure Date 2010-10-12
Arrival Date 2010-11-25
Principal Scientist(s)Andrew Rees (Plymouth Marine Laboratory)
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