Metadata Report for BODC Series Reference Number 1336121
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
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
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.
JC025 Dissolved Inorganic Nutrients Sampling Document
Originator's protocol for data acquisition and analysis
Water samples were drawn from the CTD rosette bottles deployed during the JC025 cruise with the majority of the sampling effort concentrated in the top 140 m of the water column.
Samples were analysed within 24 hours of collection and refridgerated prior to analysis. Measurements were made using standard colorimetric methods with a Lachat Autoanalyser.
Primary standards were prepared as follows:
- Ammonium 10013.27 µM
- Phosphate 10028.95 µM
- Nitrate 10072.30 µM
- Silicate 10511.86 µM
A mixed nutrient stock was prepared from adding 1 ml NH4, 0.5 ml PO4, 2 ml SiO2 and 3 ml NO3 of the primary standards, as listed above, and diluting to 100 ml. Five working stocks were subsequently prepared by diluting down the mixed nutrient stock, giving the highest concentration of 5 µM NH4, 2.5 µM PO4, 10.5 µM SiO2 and 15.1 µM NO3. Analyses of triplicate samples showed that results were reproducible to within 5% at concentrations >1 µM, with errors increasing at lower concentrations.
References
Sharples, J., et al. (2009) JC025 Cruise Report, Celtic Sea, 2 July - 27 July 2008. Proudman Oceanographic Laboratory, UK.
Available - JC025 Cruise Report
BODC data processing procedures
The nutrient data were supplied to BODC in Microsoft Excel format and values were extracted from these and saved in ASCII format prior to being loaded into the project database under the ORACLE Relational Database Management System without modification. Data that were considered unrealistic and lay outside of the permitted range for the parameter code were flagged suspect.
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
Originator's Parameter | Unit | Description | BODC Parameter code | BODC Unit | Comments |
---|---|---|---|---|---|
Ammonium | µM | Concentration of ammonium {NH4} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | AMONAATX | µmol/L | - |
Standard deviation of ammonium | µM | Concentration standard deviation of ammonium {NH4} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | SDAMAATX | µmol/L | - |
Phosphate | µM | Concentration of phosphate {PO4} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | PHOSAATX | µmol/L | - |
Standard deviation of phosphate | µM | Concentration standard deviation of phosphate {PO4} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | SDPHAATX | µmol/L | - |
Silicate | µM | Concentration of silicate {SiO4} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | SLCAAATX | µmol/L | - |
Standard deviation of silicate | µM | Concentration standard deviation of silicate {SiO4} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | SLSDAATX | µmol/L | - |
Nitrate | µM | Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | NTRZAATX | µmol/L | - |
Standard deviation of nitrate | µM | Concentration standard deviation of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | SDNZAATX | µmol/L | - |
Project Information
No Project Information held for the Series
Data Activity or Cruise Information
Data Activity
Start Date (yyyy-mm-dd) | 2008-07-21 |
End Date (yyyy-mm-dd) | 2008-07-21 |
Organization Undertaking Activity | Proudman Oceanographic Laboratory (now National Oceanography Centre, Liverpool) |
Country of Organization | United Kingdom |
Originator's Data Activity Identifier | JC025_CTD_JC025_CTD035 |
Platform Category | lowered unmanned submersible |
BODC Sample Metadata Report for JC025_CTD_JC025_CTD035
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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237074 | 20.00 | 1 | 1 | 97.50 | 97.90 | 96.80 | Niskin bottle | No problem reported | ||
237075 | 20.00 | 2 | 2 | 97.40 | 97.90 | 96.80 | Niskin bottle | No problem reported | ||
237076 | 20.00 | 3 | 3 | 62.10 | 62.50 | 61.80 | Niskin bottle | No problem reported | ||
237077 | 20.00 | 4 | 4 | 62.20 | 62.60 | 61.90 | Niskin bottle | No problem reported | ||
237078 | 20.00 | 5 | 5 | 42.00 | 42.20 | 41.70 | Niskin bottle | No problem reported | ||
237079 | 20.00 | 6 | 6 | 42.10 | 42.30 | 41.80 | Niskin bottle | No problem reported | ||
237080 | 20.00 | 7 | 7 | 37.10 | 37.30 | 36.90 | Niskin bottle | No problem reported | ||
237081 | 20.00 | 8 | 8 | 37.00 | 37.30 | 36.80 | Niskin bottle | No problem reported | ||
237082 | 20.00 | 9 | 9 | 32.00 | 32.30 | 31.90 | Niskin bottle | No problem reported | ||
237083 | 20.00 | 10 | 10 | 31.90 | 32.20 | 31.80 | Niskin bottle | No problem reported | ||
237084 | 20.00 | 11 | 11 | 26.90 | 27.30 | 26.90 | Niskin bottle | No problem reported | ||
237085 | 20.00 | 12 | 12 | 26.90 | 27.10 | 26.80 | Niskin bottle | No problem reported | ||
237086 | 20.00 | 13 | 13 | 21.90 | 22.40 | 22.00 | Niskin bottle | No problem reported | ||
237087 | 20.00 | 14 | 14 | 21.90 | 22.10 | 21.80 | Niskin bottle | No problem reported | ||
237088 | 20.00 | 15 | 15 | 17.00 | 17.20 | 17.00 | Niskin bottle | No problem reported | ||
237089 | 20.00 | 16 | 16 | 16.90 | 17.10 | 16.90 | Niskin bottle | No problem reported | ||
237090 | 20.00 | 17 | 17 | 11.80 | 12.00 | 11.80 | Niskin bottle | No problem reported | ||
237091 | 20.00 | 18 | 18 | 11.90 | 12.20 | 11.90 | Niskin bottle | No problem reported | ||
237092 | 20.00 | 19 | 19 | 3.50 | 3.80 | 3.60 | Niskin bottle | No problem reported | ||
237093 | 20.00 | 20 | 20 | 3.40 | 3.60 | 3.50 | Niskin bottle | No problem reported | ||
237094 | 20.00 | 21 | 21 | 3.50 | 3.70 | 3.60 | Niskin bottle | No problem reported | ||
237095 | 20.00 | 22 | 22 | 3.60 | 3.80 | 3.70 | Niskin bottle | No problem reported | ||
237096 | 20.00 | 23 | 23 | 3.50 | 3.70 | 3.60 | Niskin bottle | No problem reported | ||
237097 | 20.00 | 24 | 24 | 3.60 | 3.70 | 3.60 | 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 | JC025 |
Departure Date | 2008-07-02 |
Arrival Date | 2008-07-27 |
Principal Scientist(s) | Jonathan Sharples (Proudman Oceanographic Laboratory) |
Ship | RRS James Cook |
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 |