Metadata Report for BODC Series Reference Number 1875229
Metadata Summary
Problem Reports
Data Access Policy
Narrative Documents
Project Information
Data Activity or Cruise Information
Fixed Station Information
BODC Quality Flags
SeaDataNet Quality Flags
Metadata Summary
Data Description |
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Data Identifiers |
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Time Co-ordinates(UT) |
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Spatial Co-ordinates | |||||||||||||||||||||||||
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Parameters |
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Definition of BOTTFLAG | |||||||||||||||||||||||||
BOTTFLAG | Definition |
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0 | The sampling event occurred without any incident being reported to BODC. |
1 | The filter in an in-situ sampling pump physically ruptured during sample resulting in an unquantifiable loss of sampled material. |
2 | Analytical 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. |
3 | The 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. |
4 | During 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. |
5 | Water was reported to be escaping from the bottle as the rosette was being recovered. |
6 | The bottle seals were observed to be incorrectly seated and the bottle was only part full of water on recovery. |
7 | Either 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). |
8 | There is reason to doubt the accuracy of the sampling depth associated with the sample. |
9 | The bottle air vent had not been closed prior to deployment giving rise to a risk of sample contamination through leakage. |
Definition of Rank |
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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
TitraLab TIM90, ABU91/ABU93 Automated Titration System
A modular, automated titration system for the laboratory. This includes a TIM90 titration manager, which can manage up to 3 burettes and store 40 methods; and either an ABU 91 Autoburette (one burette), or an ABU 93 Triburette (three burettes), both with 1 ml, 5 ml, 10 ml and 25 ml selectable quantities.
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.
DY052 discrete CTD salinity, inorganic nutrients and dissolved oxygen samples
Originator's Protocol for Data Acquisition and Analysis
The following information contains extracts from the DY052 cruise report.
Discrete samples were taken from the majority of the 89 CTD casts made during the DY052 Extended Ellet Line cruise. The samples were taken to measure salinity, dissolved oxygen and nutrient concentrations and were analysed as follows:
Salinity
Salinity samples were drawn from each unique depth. When two bottles were fired at the same depth only one bottle was sampled. Bottle samples were collected after oxygen and carbon into glass bottles with plastic inserts and caps. Some bottles on the Scottish Shelf east of Barra were not sampled due to the strong salinity signals on the shelf and to reduce Autosal operator workload when arriving in port. For each sample, the bottle and cap was rinsed three times and then filled with sample. The neck, threads, and cap were carefully dried, to prevent salt crystals from forming around the opening, and the insert and cap were put on the bottle for storage. Filled salt bottles were placed in the Autosal lab and allowed a minimum of 24 hours to reach the ambient lab temperature before analysis on the Autosal.
Oxygen
Dissolved oxygen concentrations were measured using the seawater samples. Sampling and analysis were performed 24hrs a day from every CTD cast using Winkler photometric auto-titration. Methodologies followed those documented in GO-SHIP protocols (Langdon,2010) and based on the standard methodologies of Carpenter 1965 adapted for large scale hydrographic studies (e.g. Culberson, 1991 and Dickson, 1995).
Nutrients
Nutrient samples were collected in 50ml acid pre-cleaned polythene vials directly from the CTD spigots without the use of a tube and using a single half-full rinse prior to collection. Samples were always analyzed within 24 hours of collection and stored in low light conditions at room temperature prior to analysis if analysis time exceeded eight hours after collection time. Measurement was conducted using a Lachat QuikChem 8500 flow injection autoanalyser (Hach Lange). After analysis, the 50ml tubes were double rinsed and reused for subsequent CTD sample collection.
BODC Data Processing Procedures
The sample data were supplied to BODC in an MSTAR format. This file format was converted to ASCII and data were loaded into BODC's ocean database under the ORACLE Relational Database Management System without modification. There were no replicates and no flags were added to the data.
Originator's Variable | Units | Description | BODC Parameter Code | Units | Comments |
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Botpsal | psu | Practical salinity of the water body by bench salinometer and computation using UNESCO 1983 algorithm | PSALBSTX | psu | - |
Botoxy | µmol/kg | Concentration of oxygen {O2 CAS 7782-44-7} per unit mass of the water body [dissolved plus reactive particulate phase] by Winkler titration | DOKGWITX | µmol/kg | - |
Silc | µmol/l | Concentration of silicate {SiO44- CAS 17181-37-2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | SLCAAATX | µmol/l | - |
Phos | µmol/l | Concentration of phosphate {PO4} per unit volume of the water body [unknown phase] by colorimetric autoanalysis | PHOSAATX | µmol/l | - |
Totnit | µmol/l | Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [unknown phase] by colorimetric autoanalysis | NTRZAATX | µmol/l | - |
Data Quality Report
There are a few instances where data exists in the Mstar file where no bottle was fired and so has no corresponding depth. This occurred three times for nutrients and once for oxygen. Without being able to confirm the cast and bottle these samples came from BODC have not been able to load the data to the BODC database. Below are these instances -
- Cast 19, bottle 23 (Silc -0.18, Phos 0.26, Totnit 4.7 (µmol/l))
- Cast 24, bottle 17 (Silc 0.95, Phos 0.2, Totnit 2.23 (µmol/l))
- Cast 63, bottle 12 (Silc 0.56, Phos 0.04, Totnit 0.05 (µmol/l))
- Cast 28, bottle 2 (Botoxy 239.21µmol/kg)
Project Information
No Project Information held for the Series
Data Activity or Cruise Information
Data Activity
Start Date (yyyy-mm-dd) | 2016-06-23 |
End Date (yyyy-mm-dd) | 2016-06-23 |
Organization Undertaking Activity | Scottish Association for Marine Science |
Country of Organization | United Kingdom |
Originator's Data Activity Identifier | DY052_CTD_CTD088 |
Platform Category | lowered unmanned submersible |
No Document Information Held for the Series
Related Data Activity activities are detailed in Appendix 1
Cruise
Cruise Name | DY052 |
Departure Date | 2016-06-07 |
Arrival Date | 2016-06-24 |
Principal Scientist(s) | Stefan F Gary (Scottish Association for Marine Science) |
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 |
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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 |
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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: DY052_CTD_CTD088
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 Identifier | Data Category | Start date/time | Start position | Cruise |
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2149760 | Water sample data | 2016-06-23 04:45:56 | 57.65005 N, 11.0817 W | RRS Discovery DY052 |