Search the data

Metadata Report for BODC Series Reference Number 1748138


Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
NameCategories
Niskin bottle  discrete water samplers
Lachat QuikChem 8500 flow injection analysis system  flow injection analysers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Mr Tim Brand
Originating Organization Scottish Association for Marine Science
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) -
 

Data Identifiers

Originator's Identifier CD150_CTD_NUTS_304:56053#01
BODC Series Reference 1748138
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2003-09-07 05:35
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 22.99992 N ( 22° 60.0' N )
Longitude 66.68675 E ( 66° 41.2' E )
Positional Uncertainty 0.1 to 0.5 n.miles
Minimum Sensor or Sampling Depth 5.0 m
Maximum Sensor or Sampling Depth 704.0 m
Minimum Sensor or Sampling Height 15.0 m
Maximum Sensor or Sampling Height 714.0 m
Sea Floor Depth 719.0 m
Sea Floor Depth Source PEVENT
Sensor or Sampling Distribution Unspecified -
Sensor or Sampling Depth Datum Unspecified -
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODERankUnitsTitle
ADEPZZ011MetresDepth (spatial coordinate) relative to water surface in the water body
AMONAAD11Micromoles per litreConcentration of ammonium {NH4+ CAS 14798-03-9} per unit volume of the water body [dissolved plus reactive particulate
BOTTFLAG1Not applicableSampling process quality flag (BODC C22)
FIRSEQID1DimensionlessBottle firing sequence number
NTRIAAD11Micromoles per litreConcentration of nitrite {NO2- CAS 14797-65-0} per unit volume of the water body [dissolved plus reactive particulate
NTRZAAD11Micromoles per litreConcentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate
PHOSAAD11Micromoles per litreConcentration of phosphate {PO43- CAS 14265-44-2} per unit volume of the water body [dissolved plus reactive particulate
ROSPOSID1DimensionlessBottle rosette position identifier
SAMPRFNM1DimensionlessSample reference number
SLCAAAD11Micromoles per litreConcentration of silicate {SiO44- CAS 17181-37-2} per unit volume of the water body [dissolved plus reactive particulate

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

These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.

If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:

"Contains public sector information licensed under the Open Government Licence v1.0."


Narrative Documents

Lachat QuikChem 8500 flow injection analyzer (FIA) and Ion Chromatography (IC) system

The Lachat QuikChem 8500 can operate FIA and IC simultaneously and independently on the same instrument platform. FIA and IC are complementary analytical techniques that are commonly used in the same laboratory.

Instrument includes - sampler, dilutor, sampling pump, electronics unit, and data station.

Flow injection analysis is ideally suited for processing relatively large numbers of samples. Ion Chromatography adds the power to profile samples for a class of ionic species.

FIA Productivity Characteristics

  • Fast Startup - ~5 minutes
  • Rapid Analysis - 20 to 60 seconds is typical
  • High Sample Throughput - 60 to 120 samples per hour is typical
  • Broad Working Range - Parts per trillion to percents
  • Complete Baseline Resolution - No carryover between samples
  • Wide Dynamic Range - 2 to 3 decades is typical
  • Fast Shutdown - ~5 minutes
  • Rapid Method Changeover - ~10 minutes

New FIA Features

  • Run up to 5 channels for high productivity analysis or dedicated operation.
  • New 2-cm flow cell methods allow more signal for detection at lower levels.
  • Run Omnion 3.0 software on Windows XP, Vista, or Windows 7 operating systems.
  • Interface Omnion software in multiple languages - including Spanish, German, French, Portuguese, and Italian.

For more information about this model see the manufactures data sheet - Lachat QuikChem 8500.

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.

Discrete dissolved nutrient (ammonium, phosphate, silicate, nitrate and nitrite) samples from CTD bottles during cruise CD150

Originator's Protocol for Data Acquisition and Analysis

The RRS Charles Darwin CD150 cruise departed on the 22 August 2003 from Oman, Muscat traveling to the Arabian Sea and returned to Oman, Muscat on the 15 September 2003. RRS Charles Darwin Cruise 150 forms part of a larger programme of research ("Benthic processes in the Arabian Sea: mechanistic relationships between benthos, sediment, biogeochemistry and organic matter cycling"), focusing on the benthic biogeochemistry of the Pakistan Margin, that includes four cruises in total (CD145, 146, 150 and 151).

Sample collection

Samples were collected from a Seabird CTD containing 24 10-litre niskin bottles. The samples were initially collected in 5-litre polythene bottles and then transferred to polycarbonate bottles for use on the SAMS vacuum water filtration rig.

Sample analysis

Samples were filtered through 25 mm diameter Whatman GF/F filters and the filtrate initially collected in 250 ml polythene bottles. The dissolved nutrients were analysed on a Lachat QuikChem 8000 flow injection autoanalyser. The instrument uses flow injection modifications of classic colourimetric methods. Ammonium, phosphate, silicate and nitrate were analysed on all samples collected. By removal of the cadmium-copper reduction column in the nitrate line samples, nitrite were also analysed.

Following cruise CD150 the method of salt correction for all nutrients was changed. For more information please see pages 31/32 of the CD150 cruise report.

BODC Data Processing Procedures

BODC received discrete dissolved nutrients in an Excel spreadsheet. BODC extracted this 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.

BODC have not loaded nitrate values. This can be calculated by taking the nitrite value away from the nitrate+nitrite value.

SAMS nitrate data quality warning

SAMS have notified BODC of a problem in the analytical procedure adopted for nitrate analysis on this cruise. The problem relates to the technique used to prepare the analytical standards, which results in nitrate (and consequently nitrite) values which are typically 10-15 % higher than they should be. Absolute data values should therefore be used with extreme caution.

Content of data series

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

Originator's Parameter Units Description BODC Parameter Code Units Comments
Ammonium µmol L-1 Concentration of ammonium {NH4} per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis AMONAAD1 µmol L-1 -
Phosphate µmol L-1 Concentration of phosphate {PO4} per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis PHOSAAD1 µmol L-1 -
Silicate µmol L-1 Concentration of silicate {SiO4} per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis SLCAAAD1 µmol L-1 -
NO3 + NO2 µmol L-1 Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis NTRZAAD1 µmol L-1 -
Nitrite µmol L-1 Concentration of nitrite {NO2} per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis NTRIAAD1 µmol L-1 -

Quality Report

Negative data values were flagged as below the detection limit by the Originator. BODC have changed these values to the detection limit value with the corresponding below detection BODC flag. BODC have applied flags to the nitrate/nitrite data in light of the quality issue documented above.


Project Information


No Project Information held for the Series

Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2003-09-07
End Date (yyyy-mm-dd) 2003-09-07
Organization Undertaking ActivitySouthampton Oceanography Centre (now National Oceanography Centre, Southampton)
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierCD150_CTD_56053#01
Platform Categorylowered unmanned submersible

No Document Information Held for the Series

Cruise

Cruise Name CD150
Departure Date 2003-08-22
Arrival Date 2003-09-15
Principal Scientist(s)Brian James Bett (Southampton Oceanography Centre)
Ship RRS Charles Darwin

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