Metadata Report for BODC Series Reference Number 1305299


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 Dr Denise Smythe-Wright
Originating Organization Southampton Oceanography Centre (now National Oceanography Centre, Southampton)
Processing Status banked
Project(s) UK WOCE
 

Data Identifiers

Originator's Identifier DI233_CTD_NUTS_60:CTD13435
BODC Series Reference 1305299
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1998-05-02 00:20
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 29.49684 N ( 29° 29.8' N )
Longitude 21.32900 W ( 21° 19.7' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor Depth 2.3 m
Maximum Sensor Depth 4841.1 m
Minimum Sensor Height -
Maximum Sensor Height -
Sea Floor Depth -
Sensor Distribution Unspecified -
Sensor Depth Datum Unspecified -
Sea Floor Depth Datum Unspecified -
 

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)
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.

D233 Discrete CTD Inorganic Nutrient Sampling Document

Originator's Protocol for Data Acquisition and Analysis

Sample collection and analysis

Discrete dissolved inorganic nutrient samples were collected from Niskin bottles fired on 139 CTD casts performed during D233. Samples were collected in 30 ml plastic diluvial sample cups, each washed three times in the sample flow. Samples were stored in a 4 °C fridge (duration between 1 and 12 hours) prior to onboard analysis. 8 ml subsamples were drawn into sample cups and run on the SOC Chemlab AAII-type Auto-Analyser connected to a digital-analysis microstream data capture and reduction system. Duplicates were analysed (where possible) to ensure accuracy and to increase precision.

Primary standards were prepared in calibrated 500 ml glass volumetric flasks (calibrated polyethylene volumetric flasks for silicate), two standard solution for each nutrient being required for the cruise. These utilised pre-weighed salts measured prior to the cruise. Sets of working standards were typically made up from these on a daily basis in 100 ml calibrated polyethylene volumetric flasks, using artificial seawater (40 g/l NaCl). These were run in duplicate prior to each analytical run to enable sample calibration. Independent quality control samples were also prepared from standard solutions supplied by OSI and run (in duplicate) at intervals throughout the analysis.

The cruise report contains more in depth details of each nutrient analysis performed during the cruise.

BODC Data Processing Procedures

PSTAR-formatted CTD sample data collected on the cruise were supplied to BODC during December 1999. The inorganic nutrient data were extracted from these files and loaded into BODC's Oracle database. Flags were assigned if values were considered suspect.

Content of data series

Originator's Parameter Unit Description BODC Parameter code BODC Unit Comments
SiO 3 µmol/l Concentration of silicate per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis SLCAAATX µmol/l No unit conversion necessary
NO 2 +NO 3 µmol/l Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis NTRZAATX µmol/l No unit conversion necessary
PO 4 µmol/l Concentration of phosphate per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis PHOSAATX µmol/l No unit conversion necessary

References

Smythe-Wright, D., (1999). RRS Discovery Cruise 233, 23 APR - 01 JUN 1998. CHAOS. Cruise Report No. 24 Southampton Oceanography Centre.


Project Information

UK WOCE

The UK made a substantial contribution to the international World Ocean Circulation Experiment (WOCE) project by focusing on two important regions:

  1. Southern Ocean - links all the worlds oceans, controlling global climate.
  2. North Atlantic - directly affects the climate of Europe.

A major part of the UK effort was in the Southern Ocean and work included:

In the North Atlantic the UK undertook:

Satellite ocean surface topography, temperature and wind data were merged with in situ observations and models to create a complete description of ocean circulation, eddy motion and the way the ocean is driven by the atmosphere.

The surveys were forerunners to the international Global Ocean Observing System (GOOS). GOOS was later established to monitor annual to decadal changes in ocean circulation and heat storage which are vital in the prediction of climate change.


Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 1998-05-01
End Date (yyyy-mm-dd) 1998-05-02
Organization Undertaking ActivitySouthampton Oceanography Centre (now National Oceanography Centre, Southampton)
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierDI233_CTD_CTD13435
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for DI233_CTD_CTD13435

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
109223   10.00     4930.70 4932.20 4841.10 Niskin bottle No problem reported    
109224   10.00     4652.70 4654.20 4571.00 Niskin bottle No problem reported    
109225   10.00     4130.00 4131.50 4062.20 Niskin bottle No problem reported    
109226   10.00     3610.60 3612.10 3555.40 Niskin bottle No problem reported    
109227   10.00     3091.90 3093.40 3048.20 Niskin bottle No problem reported    
109228   10.00     2572.10 2573.60 2538.80 Niskin bottle No problem reported    
109229   10.00     2312.30 2313.80 2283.70 Niskin bottle No problem reported    
109230   10.00     2049.00 2050.50 2024.80 Niskin bottle No problem reported    
109231   10.00     1792.80 1794.30 1772.70 Niskin bottle No problem reported    
109232   10.00     1541.50 1543.00 1525.00 Niskin bottle No problem reported    
109233   10.00     1284.70 1286.20 1271.70 Niskin bottle No problem reported    
109234   10.00     1027.70 1029.20 1017.80 Niskin bottle No problem reported    
109235   10.00      823.70  825.20  816.10 Niskin bottle No problem reported    
109236   10.00      619.20  620.70  613.70 Niskin bottle No problem reported    
109237   10.00      414.80  416.30  411.20 Niskin bottle No problem reported    
109238   10.00      209.70  211.20  207.80 Niskin bottle No problem reported    
109239   10.00      159.40  160.90  157.90 Niskin bottle No problem reported    
109240   10.00      108.60  110.10  107.40 Niskin bottle No problem reported    
109241   10.00       83.10   84.60   82.10 Niskin bottle No problem reported    
109242   10.00       57.40   58.90   56.60 Niskin bottle No problem reported    
109243   10.00       32.20   33.70   31.60 Niskin bottle No problem reported    
109244   10.00       18.50   20.00   18.00 Niskin bottle No problem reported    
109245   10.00        2.70    4.20    2.30 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 D233
Departure Date 1998-04-23
Arrival Date 1998-06-01
Principal Scientist(s)Denise Smythe-Wright (Southampton Oceanography Centre)
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