Metadata Report for BODC Series Reference Number 1306764
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
Nitrate, phosphate, silicate and ammonium seawater concentrations for BAS cruise JB10 Leg 1
Originator's data acquisition and analysis
Discrete samples from vertical profiles were taken using a CTD water bottle rosette. Discrete samples were subsampled and passed through a glass fibre filter (Whatman GF/C, pore size 1.2 µm) by means of a syringe with an in-line luer-locking filtration unit. All analyses were conducted using a nutrient autoanalyser made up of Chemlab colorimeters and Ismatec pumps and custom built reaction manifolds.
Nitrate Determination of nitrate was conducted following the method described by Stainton (1974). Nitrate is reduced to nitrite by passing the sample stream through a transmission tube containing a copper-coated cadmium wire. Nitrite ions diazotise sulphanilamide then couple with N-1-naphthylethylenediamine dihydrochloride to form an azo-dye, the concentration of which is measured by absorbance at 550 nm.
Phosphate Phosphate concentration was determined following a method similar to that described by Tréguer and Le Corre (1975). Orthophosphate ions react with acidified ammonium molybdate in the presence of antimony to form phosphomolbdic acid. This is reduced by ascorbic acid to a 'molydenum blue' complex (Riley and Skirrow, 1975) the concentration of which is measured by absorbance at 630nm.
Silicate The concentration of silicate in seawater was determined using a method based on an industrial method by Technicon (1976). Silicate ions react with ammonium molybdate in acidic conditions producing silicomolybdic acid. This is reduced to a 'molybdenum blue' complex by ascorbic acid (Riley and Skirrow, 1975) and its concentration is measured by absorbance at 680 nm. Interference from phosphates at normal concentrations is eliminated by the introduction of oxalic acid into the sample stream prior to the addition of ascorbic acid.
Ammonium Ammonia is determined using a variant of the Berthelot reaction. Sodium dichloroisocyanurate is used as a hypochlorite donor (Krom, 1984) and catalysis is performed by potassium ferrocyanide. After reagent additions, the reaction stream is heated to 40°C and formation of 'indophenol blue' is promoted under longwave UV radiation (365 nm). Concentration is measured by absorbance at 630 nm.
See Whitehouse and Woodley, 1987 for full details of all instrumentation and analysis involved.
References cited
Krom M.D., 1984 Spectrophotometric determination of ammonia. A study of a modified Berthelot reaction using salicylate and dichloroisocyanurate. The Analyst, 105, 305-316.
Riley J.P. and Skirrow G., 1975. Chemical Oceanography, 3, (2nd Edition), London, Academic Press.
Stainton M.P., 1974. Simple, efficient reduction column for use in the automated determination of nitrate in water. Analytical Chemistry, 46, 1616.
Technicon Instruments Corporation, 1976. Silicates in water and wastewater. Technicon industrial method No 105-71.
Tréguer P. and Le Corre P., 1975. Manuel d'analyse des sels nutritifs dans l'eau de mer (Utilisation de l'AutoAnalyser II, Technicon, 2nd edition). Report laboratoire d'oceanologie chimique, Université de Bretagne Occidentale, Brest, France.
Whitehouse M.J. and Woodley V.R., 1987. Automated Seawater Nutrient Analysis. British Antarctic Survey, Cambridge.
BODC Data Processing Procedures
Data were received by BODC in spreadsheet format with the nutrient data from various BAS cruises in labeled worksheets (BAS_nutrient_data_1981-2009.xls). The following metadata fields were also included with the data: cruise ID, date, latitude, longitude, event number and pressure.
Parameter codes defined in the BODC parameter dictionary were mapped to the variables as follows:
| Originator's Parameter | Units | Description | BODC Parameter Code | Units | Comments |
|---|---|---|---|---|---|
| NO3 | mmol m-3 | concentration of nitrate + nitrite per unit volume of the water body (dissolved plus reactive particulate <GF/C phase) | NTRZAAD3 | µmol L-1 | No unit conversion necessary, units analogous with one another |
| NH4 | mmol m-3 | concentration of ammonium per unit volume of the water body (dissolved plus reactive particulate <GF/C phase) | AMONAAD3 | µmol L-1 | No unit conversion necessary, units analogous with one another |
| PO4 | mmol m-3 | concentration of phosphate per unit volume of the water body (dissolved plus reactive particulate <GF/C phase) | PHOSAAD3 | µmol L-1 | No unit conversion necessary, units analogous with one another |
| Si | mmol m-3 | concentration of silicate per unit volume of the water body (dissolved plus reactive particulate <GF/C phase) | SLCAAAD3 | µmol L-1 | No unit conversion necessary, units analogous with one another |
Nutrient data were received with no associated time for the sampling event. It was therefore deemed necessary to acquire times from the CTD cast data inventory for this cruise already stored at BODC. Positional data from the nutrient data file and positional data from the CTD cast metadata were used to map the correct times to the nutrient sampling events.
The depth of the water column at each sampling event has been assigned using GMT andGEBCO data.
The data were banked according to BODC standard procedures for sample data. Data were banked as received, with no averaging or other modifications applied.
Data Quality Report
There are no data quality issues to report.
Project Information
No Project Information held for the Series
Data Activity or Cruise Information
Data Activity
| Start Date (yyyy-mm-dd) | 1990-01-16 |
| End Date (yyyy-mm-dd) | 1990-01-16 |
| Organization Undertaking Activity | British Antarctic Survey |
| Country of Organization | United Kingdom |
| Originator's Data Activity Identifier | JB10 LEG 1_CTD_JB10_253 |
| Platform Category | lowered unmanned submersible |
BODC Sample Metadata Report for JB10 LEG 1_CTD_JB10_253
| 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 212012 | 11.50 | 12.50 | 11.90 | unknown | No problem reported | |||||
| 212013 | 16.50 | 17.50 | 16.80 | unknown | No problem reported | |||||
| 212014 | 24.50 | 25.50 | 24.80 | unknown | No problem reported | |||||
| 212015 | 34.50 | 35.50 | 34.70 | unknown | No problem reported | |||||
| 212016 | 45.50 | 46.50 | 45.60 | unknown | No problem reported | |||||
| 212017 | 66.50 | 67.50 | 66.40 | unknown | No problem reported | |||||
| 212018 | 88.50 | 89.50 | 88.20 | unknown | No problem reported | |||||
| 212019 | 128.50 | 129.50 | 127.80 | unknown | No problem reported | |||||
| 212020 | 210.50 | 211.50 | 209.00 | unknown | No problem reported | |||||
| 212021 | 516.50 | 517.50 | 511.70 | unknown | No problem reported | |||||
| 212022 | 1024.50 | 1025.50 | 1013.30 | unknown | No problem reported | |||||
| 212023 | 2017.50 | 2018.50 | 1990.20 | unknown | 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 | JB10 Leg 1 |
| Departure Date | 1989-12-09 |
| Arrival Date | 1990-01-24 |
| Principal Scientist(s) | Jonathan L Watkins (British Antarctic Survey), Julian Priddle (British Antarctic Survey) |
| Ship | RRS John Biscoe |
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 |
