Metadata Report for BODC Series Reference Number 1339585
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 |
|---|---|
| 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
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.
D379 discrete dissolved inorganic nutrients sampling document
Originator's protocol for data acquisition and analysis
Water samples were drawn from CTD rosette bottles fired during the cruise for inorganic nutrient analysis. Ammonia, phosphate, silicate and nitrate+nitrite were targeted, with the majority of the sampling effort concentrated in areas of the water column corresponding with changes in water mass. 49 samples were also drawn from the ship's non-toxic water supply. Due to a faulty rotary valve the phosphate line stopped working during the cruise. As it was considered more important to measure phosphate rather than ammonia, the ammonia line rotary valve was swapped for the defective phosphate one.
Samples were collected in 125 ml acid cleaned polythene bottles directly from CTD spigots without the use of a tube. Samples were stored in a fridge prior to analysis. The analysis was carried out within 24 hours of sample collection with a Lachat Quick Chem 8500 flow injection autoanalyser using the manufacturer's recommended methods.
Samples were measured in triplicate to identify instrument precision. A stock-mixed standard was prepared in deionized water with subsequent dilutions made in OSIL Low Nutrient Sea Water using the instrument auto-dilutor facility. Five standard concentrations and a blank were run in all cases and new standards were prepared every 48 hours. Using standards prepared in Low Nutrient Sea Water removes the need to do a separate salt correction. Three standard concentration ranges were prepared for the non-toxic samples and those collected across the Wyville Thomson CTD transect, depending on expected nutrient concentration.
BODC data processing procedures
The nutrient data were supplied to BODC in Microsoft Excel format. Values were extracted from this file and loaded into BODC's ORACLE relational database. Standard deviatons were calculated by the Originator. Data that were considered unrealistic were flagged suspect. Metadata collected from the various data files were favoured by BODC over the metadata recorded in the cruise report logs present in the D379 cruise report.
Content of data series
| Originator's Parameter | Unit | Description | BODC Parameter code | BODC Unit | Comments |
|---|---|---|---|---|---|
| CTD bottle ammonium | µM | Concentration of ammonium in the water column by colorimetric autoanalysis (unfiltered) | AMONAATX | µM | N/A |
| Standard deviation of CTD bottle ammonium | µM | Concentration standard deviation of ammonium in the water column by colorimetric autoanalysis (unfiltered) | SDAMAATX | µM | N/A |
| CTD bottle and discrete underway phosphate | µM | Concentration of phosphate in the water column by colorimetric autoanalysis (unfiltered) | PHOSAATX | µM | N/A |
| Standard deviation of CTD bottle and discrete underway phosphate | µM | Concentration standard deviation of phosphate in the water column by colorimetric autoanalysis (unfiltered) | SDPHAATX | µM | N/A |
| CTD bottle and discrete underway silicate | µM | Concentration of silicate in the water column by colorimetric autoanalysis (unfiltered) | SLCAAATX | µM | N/A |
| Standard deviation of CTD bottle and discrete underway silicate | µM | Concentration standard deviation of silicate in the water column by colorimetric autoanalysis (unfiltered) | SLSDAATX | µM | N/A |
| CTD bottle and discrete underway nitrate/ nitrite | µM | Concentration of nitrate and nitrite in the water column by colorimetric autoanalysis (unfiltered) | NTRZAATX | µM | N/A |
| Standard deviation of CTD bottle and discrete underway nitrate/ nitrite | µM | Concentration standard deviation of nitrate and nitrite in the water column by colorimetric autoanalysis (unfiltered) | SDNZAATX | µM | N/A |
Data quality report
No problems reported and no significant issues encountered during BODC data banking procedures.
It has been noted, however, that the silicate value for the NUT008 sample was below the detection limit. This was conveyed by a low instrument signal. The user should be aware of this when using these data.
Two silicate values (sampled on CTD cast 98 and 102) and one nitrate/ nitrite value (sampled on CTD cast 18) were negative. These values have been assigned an 'M' flag by BODC.
References cited
Griffiths C. R. et al., (2012). RRS Discovery Cruise D379, 31 Jul 2012 - 17 Aug 2012. Southampton to Reykjavic - the Extended Ellett Line. Scottish Association for Marine Science, 184pp. (Scottish Marine Institute, Oban.)
Available - Cruise D379 Internal Report
Project Information
No Project Information held for the Series
Data Activity or Cruise Information
Data Activity
| Start Date (yyyy-mm-dd) | 2012-08-07 |
| End Date (yyyy-mm-dd) | 2012-08-07 |
| Organization Undertaking Activity | Scottish Association for Marine Science |
| Country of Organization | United Kingdom |
| Originator's Data Activity Identifier | D379_CTD_C047 |
| Platform Category | lowered unmanned submersible |
BODC Sample Metadata Report for D379_CTD_C047
| 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 903224 | 10.00 | 1 | 1 | 893.90 | 894.10 | 883.60 | Niskin bottle | No problem reported | ||
| 903227 | 10.00 | 2 | 2 | 893.70 | 893.90 | 883.40 | Niskin bottle | No problem reported | ||
| 903230 | 10.00 | 3 | 3 | 733.20 | 733.40 | 725.10 | Niskin bottle | No problem reported | ||
| 903233 | 10.00 | 4 | 4 | 733.60 | 733.80 | 725.50 | Niskin bottle | No problem reported | ||
| 903236 | 10.00 | 5 | 5 | 656.40 | 656.70 | 649.30 | Niskin bottle | No problem reported | ||
| 903239 | 10.00 | 6 | 6 | 655.80 | 656.00 | 648.70 | Niskin bottle | No problem reported | ||
| 903242 | 10.00 | 7 | 7 | 527.70 | 527.90 | 522.10 | Niskin bottle | No problem reported | ||
| 903245 | 10.00 | 8 | 8 | 528.80 | 529.00 | 523.20 | Niskin bottle | No problem reported | ||
| 903248 | 10.00 | 9 | 9 | 456.30 | 456.70 | 451.70 | Niskin bottle | No problem reported | ||
| 903251 | 10.00 | 10 | 10 | 456.30 | 456.40 | 451.50 | Niskin bottle | No problem reported | ||
| 903254 | 10.00 | 11 | 11 | 329.90 | 330.10 | 326.60 | Niskin bottle | No problem reported | ||
| 903257 | 10.00 | 12 | 12 | 330.10 | 330.30 | 326.80 | Niskin bottle | No problem reported | ||
| 903260 | 10.00 | 13 | 13 | 254.30 | 254.40 | 251.80 | Niskin bottle | No problem reported | ||
| 903263 | 10.00 | 14 | 14 | 254.10 | 254.40 | 251.70 | Niskin bottle | No problem reported | ||
| 903266 | 10.00 | 15 | 15 | 178.40 | 178.60 | 176.70 | Niskin bottle | No problem reported | ||
| 903269 | 10.00 | 16 | 16 | 178.30 | 178.50 | 176.60 | Niskin bottle | No problem reported | ||
| 903272 | 10.00 | 17 | 17 | 100.60 | 100.80 | 99.70 | Niskin bottle | No problem reported | ||
| 903275 | 10.00 | 18 | 18 | 100.70 | 100.80 | 99.80 | Niskin bottle | No problem reported | ||
| 903278 | 10.00 | 19 | 19 | 50.20 | 50.50 | 49.90 | Niskin bottle | No problem reported | ||
| 903281 | 10.00 | 20 | 20 | 50.20 | 50.40 | 49.80 | Niskin bottle | No problem reported | ||
| 903284 | 10.00 | 21 | 21 | 4.90 | 5.20 | 5.00 | Niskin bottle | No problem reported | ||
| 903287 | 10.00 | 22 | 22 | 4.90 | 5.10 | 4.90 | 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 | D379 |
| Departure Date | 2012-07-30 |
| Arrival Date | 2012-08-17 |
| Principal Scientist(s) | Colin R Griffiths (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 |
|---|---|
| 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 |
