Metadata Report for BODC Series Reference Number 2129119
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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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
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.
D376 Discrete CTD Inorganic Nutrient Sampling Document
Originator's Protocol for Data Acquisition and Analysis
Sample collection
Triplicate inorganic nutrient samples were drawn from multiple water bottles on 38 of the CTD casts performed on D376. Samples were collected in 60 ml HDPE bottles which were triple rinsed under the flow from each Niskin bottle prior to being filled to 80 % capacity. The bottles were immediately capped and taken to the onboard chemistry laboratory for analysis within two hours.
Sample analysis
A Bran and Luebbe QuAAtro 5-Channel Nutrient Auto-analyser was used for the determination of nutrient concentrations.
Analytical standards were prepared onboard using high purity salts. Check standards, using commercially available nutrient standards, were also prepared. Standards were prepared in artificial seawater (consisting of 35 g sodium chloride and 0.5 g sodium bicarbonate dissolved in 1 litre of Milli-Q water). During analysis, baseline and drift corrections were applied to ensure analytical integrity. The precision for all nutrients was in excess of 1 %.
Nitrate+Nitrite
A copperised cadmium reduction coil was used to reduce nitrate to nitrite at pH 8. This nitrite (from nitrate), together with nitrite already present in the sample, was then reacted with sulphanilamide and N-(1-naphthyl)-ethylenediamine dihydrochloride (NEDD) to produce a red-purple azo dye, which was measured colorimetrically.
The analytical detection limit for nitrate+nitrite was 0.1 µmol/l.
Nitrite
The nitrite present in each sample was determined in the same manner as above, but without using the copperised cadmium column.
The analytical detection limit for nitrite was 0.05 µmol/l.
Phosphate
Phosphate concentration was determined by reaction of phosphate in the sample with molybdate and antimony ions and subsequent reduction with ascorbic acid to produce a phospho-molybdenum complex which was measured colorimetrically
The analytical detection limit for phosphate was 0.05 µmol/l.
Silicate
Silicate concentration was established colorimetrically by reducing a silico-molybdate complex in acid solution to a molybdenum blue complex using ascorbic acid. The addition of oxalic acid ensured any interference from phosphate was minimal.
The analytical detection limit for silicate was 0.1 µmol/l.
Ammonium
Ammonium concentrations were determined by reaction with o-phthalaldehyde (OPA) at 75 °C in the presence of a borate buffer. The addition of sodium sulphite resulted in the production of a fluorescent species in proportion to the ammonium concentration present. This was measured fluorimetrically using a JASCO FP-2020 Intelligent fluorescence detector.
The analytical detection limit for ammonium was 0.05 µmol/l.
BODC Data Processing Procedures
A MS Excel spreadsheet containing biogeochemistry data was supplied to BODC by the data originator, Claire Mahaffey (University of Liverpool). Mean values of the triplicate nutrient analyses were provided alongside standard deviations and coefficients of variation (CV) for each value. Quality control markers were also included.
The mean values (together with associated standard deviations) were loaded to BODC's ocean database under the ORACLE Relational Database Management System. Originator flags, where present, were also mapped across (to BODC 'L' flags). There were some occurrences where derived nitrate values had been flagged by the originator. BODC have assigned corresponding 'M' flags to the associated nitrate+nitrite and nitrite values in these instances as calculation of nitrate is intrinsically linked to these other variables.
The CV values were not ingested into the database as these are derived measurements which can easily be reproduced (standard deviation divided by mean value).
Content of data series
Originator's Parameter | Unit | Description | BODC Parameter code | BODC Unit | Comments |
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Mean N+N | µmol/l | Concentration of nitrate+nitrite per unit volume of the water body | NTRZAATX | µmol/l | No unit conversion necessary |
Stdev | µmol/l | Concentration standard deviation of nitrate+nitrite per unit volume of the water body | SDNZAATX | µmol/l | No unit conversion necessary |
Mean Nitrite | µmol/l | Concentration of nitrite per unit volume of the water body | NTRIAATX | µmol/l | No unit conversion necessary |
Stdev | µmol/l | Concentration standard deviation of nitrite per unit volume of the water body | NTSDAATX | µmol/l | No unit conversion necessary |
Nitrate | µmol/l | Concentration of nitrate per unit volume of the water body | - | - | Not entered into BODC database - nitrate is derived by subtracting nitrite from nitrate+nitrite values |
Stdev | µmol/l | Concentration standard deviation of nitrate per unit volume of the water body | - | - | Not entered into BODC database - derived product (see above) |
Mean Silicate | µmol/l | Concentration of silicate per unit volume of the water body | SLCAAATX | µmol/l | No unit conversion necessary |
Stdev | µmol/l | Concentration standard deviation of silicate per unit volume of the water body | SLSDAATX | µmol/l | No unit conversion necessary |
Mean Phosphate | µmol/l | Concentration of phosphate per unit volume of the water body | PHOSAATX | µmol/l | No unit conversion necessary |
Stdev | µmol/l | Concentration standard deviation of phosphate per unit volume of the water body | SDPHAATX | µmol/l | No unit conversion necessary |
Mean Ammonium | µmol/l | Concentration (nM sensitivity) of ammonium per unit volume of the water body | AMONNAKA | µmol/l | No unit conversion necessary |
Stdev | µmol/l | Concentration standard deviation (nM sensitivity) of ammonium per unit volume of the water body | AMONNMSD | µmol/l | No unit conversion necessary |
References
Inall, M. E. et al.,(2012). 'Cruise D376 Swansea to Southampton FASTNEt Cruise to the Celtic Sea Shelf Edge'. Internal Report No 277, Scottish Association for Marine Science.
Project Information
Fluxes Across Sloping Topography of the North East Atlantic (FASTNEt)
Background
The FASTNEt consortium was funded to deliver NERC's Ocean Shelf Edge Exchange Programme. Commencing in October 2011, this four year study aims to couple established observational techniques, such as moorings and CTDs, with the very latest in autonomous sampling initiatives - including use of Autosub Long Range and gliders. With the aid of novel model techniques, these observations will be utilised to construct a new paradigm of Ocean/Shelf exchange.
Shelf edge regions mark the gateway between the world's deep oceans and shallower coastal seas, linking terrestrial, atmospheric and oceanic carbon pools and influencing biogeochemical fluxes. Shelf edge processes can influence near-shore productivity (and fisheries) and ultimately affect global climate.
FASTNEt brings together researchers from multiple UK organisations. Further collaboration has been established with five Project Partners: the UK Met Office, Marine Scotland Science, Agri-Food and Biosciences Institute, Marine Institute Ireland and Scripps Institution of Oceanography.
Scientific Objectives
- To determine the seasonality of physical gradients and exchange across the shelf edge by deploying new observational technologies (gliders, Autosub Long Range) and established techniques (long term moorings, drifters)
- To quantify key exchange mechanisms and to collect new data targeted at testing and improving high resolution models of the shelf edge, by carrying out detailed process studies in contrasting regions of the shelf edge of the NE Atlantic margin
- To develop a new parameterisation of shelf edge exchange processes suitable for regional-scale models, using improved resolution numerical, and new empirical models constrained by the observations
- To test the new parameterisations in a regional model in the context of making an assessment of inter-annual variability of ocean-shelf exchange.
Fieldwork
Three survey sites on the UK shelf edge have been selected for FASTNEt. These are a) the Celtic Sea shelf edge, b) Malin shelf and c) North Scotland shelf. Fieldwork is centred around two research cruises. The first, to the Celtic Sea, on RRS Discovery in June 2012. The second cruise visits the Malin shelf on RRS James Cook, during summer 2013. In addition to these dedicated cruises, opportunist cruise activity to the North Scotland shelf has been agreed with project partner Marine Scotland Science. Autonomous technologies will complement observations made during the cruises and provide knowledge of seasonal and inter-annual variability in exchange processes.
Instrumentation
Types of instruments/measurements:
- Gliders
- Autosub Long Range
- Drifter buoys
- Scanfish
- Microstructure profilers
- Moored CTD/CT loggers and ADCPs
- Shipboard measurements: CTD, underway, nutrients (and other discrete sampling), LADCP, ADCP.
Contacts
Collaborator | Organisation |
---|---|
Prof. Mark Inall (lead) | Scottish Association for Marine Science, U.K |
Dr. Jason Holt | National Oceanography Centre, U.K |
Dr. Peter Miller | Plymouth Marine Laboratory, U.K |
Dr. Mattias Green | Bangor University, U.K |
Prof. Jonathan Sharples | University of Liverpool, U.K |
Dr. Vasyl Vlasenko | University of Plymouth, U.K |
Data Activity or Cruise Information
Data Activity
Start Date (yyyy-mm-dd) | 2012-06-19 |
End Date (yyyy-mm-dd) | 2012-06-19 |
Organization Undertaking Activity | Scottish Association for Marine Science |
Country of Organization | United Kingdom |
Originator's Data Activity Identifier | D376_CTD_C025 |
Platform Category | lowered unmanned submersible |
BODC Sample Metadata Report for D376_CTD_C025
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 |
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922058 | 10.00 | 1 | 1 | 101.50 | 101.80 | 100.80 | Niskin bottle | No problem reported | ||
922061 | 10.00 | 2 | 2 | 101.60 | 101.70 | 100.70 | Niskin bottle | No problem reported | ||
922064 | 10.00 | 3 | 3 | 53.50 | 53.70 | 53.10 | Niskin bottle | No problem reported | ||
922067 | 10.00 | 4 | 4 | 53.40 | 53.70 | 53.00 | Niskin bottle | No problem reported | ||
922070 | 10.00 | 5 | 5 | 49.30 | 49.60 | 49.10 | Niskin bottle | No problem reported | ||
922073 | 10.00 | 6 | 6 | 49.40 | 49.60 | 49.10 | Niskin bottle | No problem reported | ||
922076 | 10.00 | 7 | 7 | 44.40 | 44.50 | 44.10 | Niskin bottle | No problem reported | ||
922079 | 10.00 | 8 | 8 | 44.40 | 44.50 | 44.10 | Niskin bottle | Bottle misfire | Bottle did not fire | |
922082 | 10.00 | 9 | 9 | 41.40 | 41.60 | 41.10 | Niskin bottle | Bottle misfire | Bottle did not fire | |
922085 | 10.00 | 10 | 10 | 41.40 | 41.50 | 41.10 | Niskin bottle | Bottle misfire | Bottle did not fire | |
922088 | 10.00 | 11 | 11 | 16.00 | 16.10 | 15.90 | Niskin bottle | No problem reported | ||
922091 | 10.00 | 12 | 12 | 15.60 | 15.90 | 15.60 | 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 | D376 |
Departure Date | 2012-06-11 |
Arrival Date | 2012-07-02 |
Principal Scientist(s) | Mark E Inall (Scottish Association for Marine Science) |
Ship | RRS Discovery |
Complete Cruise Metadata Report is available here
Fixed Station Information
Fixed Station Information
Station Name | FASTNEt CTD Station A12 |
Category | Offshore location |
Latitude | 49° 12.00' N |
Longitude | 8° 30.00' W |
Water depth below MSL | 148.0 m |
FASTNEt CTD Station A12
Station A12 was a CTD Station which was occupied repeatedly during FASTNEt cruise D376.
In total 12 casts were performed between 18/06/2012 and 19/06/2012, with the CTD package returning briefly to deck between casts in order for the ship to reposition.
The nominal position of Station A12 was 49.2° N, 8.5° W.
Related Fixed Station activities are detailed in Appendix 1
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: FASTNEt CTD Station A12
Related series for this Fixed Station 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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1169136 | CTD or STD cast | 2012-06-18 22:21:23 | 49.20016 N, 8.50037 W | RRS Discovery D376 |
2129015 | Water sample data | 2012-06-18 22:36:38 | 49.19993 N, 8.50246 W | RRS Discovery D376 |
1169148 | CTD or STD cast | 2012-06-18 23:35:00 | 49.20305 N, 8.50245 W | RRS Discovery D376 |
2129027 | Water sample data | 2012-06-18 23:44:31 | 49.20393 N, 8.50546 W | RRS Discovery D376 |
1169161 | CTD or STD cast | 2012-06-19 00:34:59 | 49.20367 N, 8.50373 W | RRS Discovery D376 |
2129039 | Water sample data | 2012-06-19 00:43:37 | 49.20607 N, 8.50481 W | RRS Discovery D376 |
1169173 | CTD or STD cast | 2012-06-19 01:31:06 | 49.20465 N, 8.49405 W | RRS Discovery D376 |
2129040 | Water sample data | 2012-06-19 01:40:08 | 49.20641 N, 8.49472 W | RRS Discovery D376 |
1169185 | CTD or STD cast | 2012-06-19 02:33:49 | 49.19718 N, 8.49856 W | RRS Discovery D376 |
2129052 | Water sample data | 2012-06-19 02:43:22 | 49.19864 N, 8.49878 W | RRS Discovery D376 |
1169197 | CTD or STD cast | 2012-06-19 03:37:48 | 49.20055 N, 8.4974 W | RRS Discovery D376 |
2129064 | Water sample data | 2012-06-19 03:45:28 | 49.20112 N, 8.49552 W | RRS Discovery D376 |
1169204 | CTD or STD cast | 2012-06-19 04:33:12 | 49.20026 N, 8.49875 W | RRS Discovery D376 |
2129076 | Water sample data | 2012-06-19 04:45:33 | 49.20081 N, 8.49682 W | RRS Discovery D376 |
1169216 | CTD or STD cast | 2012-06-19 05:34:21 | 49.19975 N, 8.49862 W | RRS Discovery D376 |
2129088 | Water sample data | 2012-06-19 05:45:05 | 49.19986 N, 8.49767 W | RRS Discovery D376 |
1169228 | CTD or STD cast | 2012-06-19 06:33:00 | 49.19866 N, 8.49998 W | RRS Discovery D376 |
2129107 | Water sample data | 2012-06-19 06:44:52 | 49.19818 N, 8.50007 W | RRS Discovery D376 |
1169241 | CTD or STD cast | 2012-06-19 07:52:42 | 49.19781 N, 8.49924 W | RRS Discovery D376 |
1169253 | CTD or STD cast | 2012-06-19 08:38:46 | 49.19984 N, 8.49902 W | RRS Discovery D376 |
2129120 | Water sample data | 2012-06-19 08:48:10 | 49.19959 N, 8.50001 W | RRS Discovery D376 |
1169265 | CTD or STD cast | 2012-06-19 09:36:15 | 49.19951 N, 8.50067 W | RRS Discovery D376 |
2129132 | Water sample data | 2012-06-19 09:45:12 | 49.19942 N, 8.50203 W | RRS Discovery D376 |