Metadata Report for BODC Series Reference Number 1267180


Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
NameCategories
unknown  unknown
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Dr John Stephens
Originating Organization Plymouth Marine Laboratory
Processing Status banked
Project(s) FEEP
 

Data Identifiers

Originator's Identifier PO311_CTD_NUTS_688:CTD_092
BODC Series Reference 1267180
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2004-05-18 09:26
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 27.57625 N ( 27° 34.6' N )
Longitude 22.38417 W ( 22° 23.1' W )
Positional Uncertainty Unspecified
Minimum Sensor Depth 2.1 m
Maximum Sensor Depth 141.0 m
Minimum Sensor Height 4732.0 m
Maximum Sensor Height 4870.9 m
Sea Floor Depth 4873.0 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
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
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

PO311 Discrete CTD Nutrients Sampling Document

Originator's Protocol for Data Acquisition and Analysis

The FS Poseidon PO311 cruise departed on the 29 April 2004 from Santa Cruz de Tenerife, Spain and returned on the 24 May 2004. The cruise set out to test the hypothesis that: The supply of, and the interaction between iron and phosphorus control biological activity and fluxes in the subtropical North Atlantic.

Sample collection

Water samples were collected from a subset of CTD profiles. Samples were generally collected from 8 standard depths determined by light levels appropriate to production rate experiments.

Sample analysis

A total of 41 CTD casts were analysed for nutrients: nitrate, nitrite, phosphate and silicate using a Technicon AAII, five channel segmented flow autoanalyser within two hours of collection. Phosphate and silicate were determined according to (Kirkwood, 1989), nitrate and nitrite according to (Brewer and Riley, 1965) and (Grasshoff, 1976) respectively.

Additional analyses were undertaken when required for standards concentration confirmation and in-situ deck incubations.

BODC Data Processing Procedures

Discrete nutrient samples were provided to BODC in Excel format. BODC extracted the data and merged with information from the associated Sea-Bird .btl files (also provided). These data were loaded to BODC's ocean database under the ORACLE Relational Database Management System. Data that were considered unrealistic were flagged suspect.

Samples in the database with a flag of "<" had concentrations below the specified detection limits. For nitrate and nitrite this was 0.01 µM and for phosphate this was 0.02 µM. There were no values below detection for silicate.

For any one experiment up to four CTDs were used to collect the water by targeting different depths for water collection. The original file only listed the possible CTDs for each experiment. BODC therefore matched as best as possible to the correct CTD and niskin number by using depth as a reference. Where duplicate depths were targeted, the bottle that fired first has been chosen.

For CTD cast 014, there was a large depth discrepancy. The Originator supplied a depth of 110 m and this has been linked to a firing depth of 93 m which was the closest firing depth.

No other discrepancies were found between the Originator's metadata and the metadata held centrally in the database.

Content of data series

The Originator's variables were mapped to appropriate BODC parameter codes as follows:

Originator's Parameter Unit Description BODC Parameter code BODC Unit Comments
Nitrate + Nitrite Micromoles per litre Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis NTRZAATX Micromoles per litre No unit conversion necessary
Nitrite Micromoles per litre Concentration of nitrite {NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis NTRIAATX Micromoles per litre No unit conversion necessary
Phosphate Micromoles per litre Concentration of phosphate {PO 4 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis PHOSAATX Micromoles per litre No unit conversion necessary
Silicate Micromoles per litre Concentration of silicate {SiO 4 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis SLCAAATX Micromoles per litre No unit conversion necessary

References

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

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

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

Rees A. et al., 2004. 'Plymouth Marine Laboratory Core cruise 2004 Phosphate and Iron Addition Experiment (FeeP)'. Cruise Report Plymouth Marine Laboratory.


Project Information

FeeP - Phosphate and Iron Addition Experiment

Who funded the programme?

The Natural Environment Research Council (NERC).

Who was involved in the programme?

The programme was a collaboration lead by Plymouth Marine Laboratory (PML) and involved scientists from the National Institute of Water and Atmospheric Research, New Zealand, Laboratoire Arago, France and the University of East Anglia.

What was the programme about?

The programme was a two ship exercise using RRS Charles Darwin and RV Pseidon to investigate the hypothesis that:

"The supply of, and interaction between, iron and phosphorus control biological activity and fluxes in the subtropical North Atlantic."

When was the programme active?

The project was carried out in 2004.

Brief summary of the programme fieldwork/data

An experimental area in international waters to the west of the Canary Islands was selected following an intense period of vertical and horizontal mapping by the Charles Darwin. Using SF6 as a tracer for amended waters, two separate experiments were performed: The first (5th - 15th May) involved the addition of 20 tonnes of anhydrous monosodium phosphate at 10 m depth over an area of approximately 25 km2, centered at 27.8 oN 23.3 oW. The second experiment was conducted following a mid-cruise return by the Poseidon to Tenerife between 16th May and 22nd May, at 27.5 oN 22.5 oW, when 5 tonnes of acidified iron sulphate were added over the first 12 hours, then following a brief recovery period, 20 tonnes of phosphate added over the top of the iron.

Measurements of nutrient chemistry, gas exchange and biological activity were monitored prior to and after deployment (IN stations) of the fertilised patches relative to several (OUT) control stations.


Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2004-05-18
End Date (yyyy-mm-dd) 2004-05-18
Organization Undertaking ActivityPlymouth Marine Laboratory
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierPO311_CTD_CTD_092
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for PO311_CTD_CTD_092

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
172189   1 1  141.50  141.80  141.00 unknown No problem reported    
172190   2 2  121.90  122.40  121.70 unknown No problem reported    
172191   3 3  111.40  111.70  111.10 unknown No problem reported    
172192   4 4   66.80   67.10   66.90 unknown No problem reported    
172193   5 5   40.60   40.80   40.80 unknown No problem reported    
172194   6 6   31.90   32.40   32.30 unknown No problem reported    
172195   7 7   26.70   26.90   27.00 unknown No problem reported    
172196   8 8   21.80   22.10   22.20 unknown No problem reported    
172197   9 9   16.50   16.70   16.80 unknown No problem reported    
172198   10 10   17.50   17.70   17.80 unknown No problem reported    
172199   11 11   17.20   17.30   17.50 unknown No problem reported    
172200   12 12    1.50    2.10    2.10 unknown 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 PO311
Departure Date 2004-04-29
Arrival Date 2004-05-24
Principal Scientist(s)Andrew Rees (Plymouth Marine Laboratory)
Ship FS Poseidon

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