Search the data

Metadata Report for BODC Series Reference Number 1262556


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 Raymond Pollard
Originating Organization Southampton Oceanography Centre (now National Oceanography Centre, Southampton)
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) WOCE
UK WOCE
 

Data Identifiers

Originator's Identifier D223B_CTD_NUTS_32:CTD13002
BODC Series Reference 1262556
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1996-10-29 16:53
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 58.03221 N ( 58° 1.9' N )
Longitude 40.43897 W ( 40° 26.3' W )
Positional Uncertainty Unspecified
Minimum Sensor or Sampling Depth 7.2 m
Maximum Sensor or Sampling Depth 3154.5 m
Minimum Sensor or Sampling Height -
Maximum Sensor or Sampling Height -
Sea Floor Depth -
Sea Floor Depth Source -
Sensor or Sampling Distribution Unspecified -
Sensor or Sampling Depth Datum Unspecified -
Sea Floor Depth Datum Unspecified -
 

Parameters

BODC CODERankUnitsTitle
ADEPZZ011MetresDepth (spatial coordinate) relative to water surface in the water body
BOTTFLAG1Not applicableSampling process quality flag (BODC C22)
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
SAMPRFNM1DimensionlessSample reference number
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

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 and Lever Action bottles have a capacity between 1.7 and 30 L. Reversing thermometers may be attached to a spring-loaded disk that rotates through 180° on bottle closure.

D223A Discrete CTD Inorganic Nutrient Sampling Document

Originator's Protocol for Data Acquisition and Analysis

Sample collection and analysis

Duplicate discrete dissolved inorganic nutrient samples were collected from Niskin bottles fired on many of the CTD casts performed during the cruise. Clean plastic diluvial containers were rinsed three times with water from the Niskin bottle prior to being filled. One duplicate sample was stored in the refrigerator and analysed within 12 hours of sampling, the other sample stored in the ship's cold room (at 5 °C). Concentrations of silicate, nitrate/nitrite and phosphate were determined by segmented flow analysis using a Chemlab Autoanalyser. Analysis was performed in duplicate to ensure accuracy and enable greater precision. Sensor drift was also monitored at intervals throughout the process.

Primary standards were prepared in calibrated 500 ml glass volumetric flasks (calibrated polyethylene volumetric flasks for silicate), approximately every four weeks. These utilised pre-weighed salts prepared in the lead up to the cruise. Sets of working standards were typically made up from these on a daily basis in 100 ml calibrated polyethylene volumetric flasks in artificial seawater (40 g/l NaCl).

Analytical equipment functioned satisfactorily throughout the cruise. The tubing on the peristaltic pump being replaced as a precaution approximately every two weeks.

BODC Data Processing Procedures

PSTAR-formatted CTD sample data from this cruise were supplied to BODC during March 1998. 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
SiO3 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
NO2+NO3 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
PO4 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

Leach, H., Pollard, R. T., (1998). RRS Discovery Cruise 223, 28 SEP - 19 NOV 1996. VIVALDI '96. Cruise Report No. 17 Southampton Oceanography Centre.


Project Information

World Ocean Circulation Experiment (WOCE)

The World Ocean Circulation Experiment (WOCE) was a major international experiment which made measurements and undertook modelling studies of the deep oceans in order to provide a much improved understanding of the role of ocean circulation in changing and ameliorating the Earth's climate.

WOCE had two major goals:

  • Goal 1. To develop models to predict climate and to collect the data necessary to test them.

  • Goal 2. To determine the representativeness of the Goal 1 observations and to deduce cost effective means of determining long-term changes in ocean circulation.


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:

  • Two surveys, in the South Atlantic as part of the WOCE Hydrographic Programme.
  • SWINDEX, a year long study of the Antarctic Circumpolar Current (ACC) where it crosses major topography south of Africa.
  • ADOX, a study of deep water flow from the Atlantic to the Indian Ocean.
  • ACCLAIM, a study of the ACC by altimetry and island measurements.

In the North Atlantic the UK undertook:

  • NATRE, a purposeful tracer experiment to look at cross isopycnic processes.
  • CONVEX, a study of the deep ocean circulation and its changes.
  • VIVALDI, a seven year programme of seasonally repeated surveys to study the upper ocean.
  • Long-term observations of ocean climate in the North West Approaches.

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) 1996-10-29
End Date (yyyy-mm-dd) 1996-10-29
Organization Undertaking ActivitySouthampton Oceanography Centre (now National Oceanography Centre, Southampton)
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierD223B_CTD_CTD13002
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for D223B_CTD_CTD13002

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
96686   10.00     3208.60 3210.10 3154.50 Niskin bottle No problem reported    
96687   10.00     3135.00 3136.50 3082.60 Niskin bottle No problem reported    
96688   10.00     3034.50 3036.00 2984.50 Niskin bottle No problem reported    
96689   10.00     2932.90 2934.40 2885.20 Niskin bottle No problem reported    
96690   10.00     2831.10 2832.60 2785.70 Niskin bottle No problem reported    
96691   10.00     2730.10 2731.60 2687.00 Niskin bottle No problem reported    
96692   10.00     2629.30 2630.80 2588.30 Niskin bottle No problem reported    
96693   10.00     2528.70 2530.20 2489.90 Niskin bottle No problem reported    
96694   10.00     2273.20 2274.70 2239.60 Niskin bottle No problem reported    
96695   10.00     2017.80 2019.30 1989.10 Niskin bottle No problem reported    
96696   10.00     1765.10 1766.60 1741.00 Niskin bottle No problem reported    
96697   10.00     1511.80 1513.30 1492.00 Niskin bottle No problem reported    
96698   10.00     1258.20 1259.70 1242.40 Niskin bottle No problem reported    
96699   10.00     1008.20 1009.70  996.00 Niskin bottle No problem reported    
96700   10.00      808.70  810.20  799.20 Niskin bottle No problem reported    
96701   10.00      607.80  609.30  600.90 Niskin bottle No problem reported    
96702   10.00      406.90  408.40  402.30 Niskin bottle No problem reported    
96703   10.00      207.40  208.90  205.00 Niskin bottle No problem reported    
96704   10.00      107.40  108.90  106.00 Niskin bottle No problem reported    
96705   10.00       57.50   59.00   56.60 Niskin bottle No problem reported    
96706   10.00       32.60   34.10   31.90 Niskin bottle No problem reported    
96707   10.00       17.70   19.20   17.10 Niskin bottle No problem reported    
96708   10.00        7.70    9.20    7.20 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.

Related Data Activity activities are detailed in Appendix 1

Cruise

Cruise Name D223B
Departure Date 1996-10-22
Arrival Date 1996-11-19
Principal Scientist(s)Raymond T Pollard (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
B nominal value
Q value below limit of quantification

Appendix 1: D223B_CTD_CTD13002

Related series for this Data Activity are presented in the table below. Further information can be found by following the appropriate links.

If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.

Series IdentifierData CategoryStart date/timeStart positionCruise
1850734Water sample data1996-10-29 16:53:0058.03221 N, 40.43897 WRRS Discovery D223B