Metadata Report for BODC Series Reference Number 1631224
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.
AMT17 Nutrient (micro- and nano-molar) measurements from CTD bottle samples
Originator's Protocol for Data Acquisition and Analysis
Water samples were taken from the Sea-Bird CTD rosette system. They were sub-sampled into acid-clean 60 ml HDPE (nalgene) sample bottles. Analysis for nutrients was completed within 3-4 hours of sampling in all cases. Clean handling techniques were employed to avoid contamination of the samples.
The main nutrient analyser was a 5-channel Bran and Luebbe AAIII segmented flow autoanalyser. The analytical chemical methodologies used were according to Brewer and Riley (1965) for nitrate, Grasshoff (1976) for nitrite, Kirkwood (1989) for phosphate and silicate, and Mantoura and Woodward (1983) for ammonium.
Nanomolar ammonium concentrations were obtained using an adapted method from Jones (1991); this uses a fluorescent analysis technique following ammonia gas diffusion out of the samples, passing across a hydrophobic Teflon membrane due to differential pH chemistry.
Nanomolar nitrate+nitrite, nitrate and phosphate concentrations were obtained on some samples using a 3-channel nanomolar analyser. This method combines sensitive segmented flow colorimetric analytical techniques with a Liquid Waveguide Capillary Cell (LWCC).
References Cited
Brewer P.G. and Riley J.P., 1965. The automatic determination of nitrate in sea water. Deep-Sea Research, 12, 765-772.
Grasshoff K., 1976. Methods of seawater analysis. Verlag Chemie, Weiheim: 317 pp.
Jones R.D., 1991. An improved fluorescence method for the determination of nanomolar concentrations of ammonium in natural waters. Limnology and Oceanography, 36, 814-819.
Kirkwood D.S., 1989. Simultaneous determination of selected nutrients in seawater. ICES CM1989/C:29, 12pp.
Mantoura R.F.C. and Woodward E.M.S., 1983. Optimisation of the indophenol blue method for the automated determination of ammonia in estuarine waters. Estuarine, Coastal and Shelf Science, 17, 219-224.
BODC Data Processing Procedures
Data were submitted to BODC in Microsoft Excel spreadsheet format and saved to the archive with accession number PML060039. Sample metadata were checked against information held in the database. There was some discrepancies - on cast 46 there were a number of discrepancies between the log sheet and spreadsheet depth/rosette position combinations. It appears the firing sequence was entered in place of the bottle numbers and the bottles were not fired in sequence.
There was a discrepancy for cast 17 between information from the Sea-bird bottle files (used by BODC as a main reference for CTD rosette bottle metadata information) and the data originator record regarding the depth of the bottle firing. The depths from the Sea-bird log files were ~10 m deeper than those in the data originator records and the log sheets supplied to BODC. It was decided that, for the time being, the data was loaded into oracle by matching the originators' Niskin rosette position number to the depth recorded by the Sea-bird instrument. This is a consistent discrepancy for this cruise not just for this dataset.
Data from the nanomolar ammonium and LWCC systems were submitted in units of nmol l-1. Nano-molar data were divided by 1000 to convert the units to µmol l-1 for storage in the database. Users should be aware that these LWCC measurements are valid to the fourth decimal place. The data were assigned parameter codes defined in BODC parameter dictionary. Data loaded into BODC's database using established BODC data banking procedures.
A parameter mapping table is provided below;
| Originator's Parameter | Units | Description | BODC Parameter Code | Units | Comments |
|---|---|---|---|---|---|
| Ammonium (AAIII) | µmol l-1 | Concentration of ammonium {NH4} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | AMONAATX | µmol l-1 | - |
| Ammonium (nano-molar system) | nmol l-1 | Concentration (nM sensitivity) of ammonium {NH4} per unit volume of the water body [dissolved plus reactive particulate phase] by nanomolar ammonium system after Jones (1991) | AMONNATX | µmol l-1 | nmol l-1 converted to µmol l-1 (conversion used * 1/1000) |
| Nitrate+Nitrite (AAIII) | µmol l-1 | Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | NTRZAATX | µmol l-1 | - |
| Nitrate+Nitrite (LWCC nano-molar system) | nmol l-1 | Concentration (nM sensitivity) of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis with liquid waveguide capilliary cell | NTRZLWTX | µmol l-1 | nmol l-1 converted to µmol l-1 (conversion used * 1/1000) |
| Nitrite (AAIII) | µmol l-1 | Concentration of nitrite {NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | NTRIAATX | µmol l-1 | - |
| Nitrite (LWCC nano-molar system) | nmol l-1 | Concentration (nM sensitivity) of nitrite {NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis with liquid waveguide capilliary cell | NTRILWTX | µmol l-1 | nmol l-1 converted to µmol l-1 (conversion used * 1/1000) |
| Phosphate (AAIII) | µmol l-1 | Concentration of phosphate {PO4} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | PHOSAATX | µmol l-1 | - |
| Phosphate (LWCC nano-molar system) | nmol l-1 | Concentration (nM sensitivity) of phosphate {PO4} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis with liquid waveguide capilliary cell | PHOSLWTX | µmol l-1 | nmol l-1 converted to µmol l-1 (conversion used * 1/1000) |
| Silicate (AAIII) | µmol l-1 | Concentration of silicate {SiO4} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | SLCAAATX | µmol l-1 | - |
Data Quality Report
Data provided were quality checked by originator and flagged accordingly. Users should be aware there may be a number of bottle warnings provided with the data for samples that have been taken from bottles which are suspected of leaking.
Measurement precision information from data originators: The detection limits for measurements from the AAIII Bran and Luebbe autoanalyser have are 0.02 µmol l-1, except the colorimetric ammonium which has a detection limit of 0.08 µmol l-1. Samples in the database with a flag of "<" had concentrations below the specified detection limits.
At low concentrations, the values obtained by the LWCC are likely to be more accurate than those from the AAIII analyser.
Problem Report
Not applicable for this dataset.
Project Information
The Atlantic Meridional Transect - Phase 2 (2002-2006)
Who was involved in the project?
The Atlantic Meridional Transect Phase 2 was designed by and implemented by a number of UK research centres and universities. The programme was hosted by Plymouth Marine Laboratory in collaboration with the National Oceanography Centre, Southampton. The universities involved were:
- University of Liverpool
- University of Newcastle
- University of Plymouth
- University of Southampton
- University of East Anglia
What was the project about?
AMT began in 1995, with scientific aims to assess mesoscale to basin scale phytoplankton processes, the functional interpretation of bio-optical signatures and the seasonal, regional and latitudinal variations in mesozooplankton dynamics. In 2002, when the programme restarted, the scientific aims were broadened to address a suite of cross-disciplinary questions concerning ocean plankton ecology and biogeochemistry and the links to atmospheric processes.
The objectives included the determination of:
- how the structure, functional properties and trophic status of the major planktonic ecosystems vary in space and time
- how physical processes control the rates of nutrient supply to the planktonic ecosystem
- how atmosphere-ocean exchange and photo-degradation influence the formation and fate of organic matter
The data were collected with the aim of being distributed for use in the development of models to describe the interactions between the global climate system and ocean biogeochemistry.
When was the project active?
The second phase of funding allowed the project to continue for the period 2002 to 2006 and consisted of six research cruises. The first phase of the AMT programme ran from 1995 to 2000.
Brief summary of the project fieldwork/data
The fieldwork on the first three cruises was carried out along transects from the UK to the Falkland Islands in September and from the Falkland Islands to the UK in April. The last three cruises followed a cruise track between the UK and South Africa, only deviating from the traditional transect in the southern hemisphere. During this phase the research cruises sampled further into the centre of the North and South Atlantic Ocean and also along the north-west coast of Africa where upwelled nutrient rich water is known to provide a significant source of climatically important gases.
Who funded the project?
Natural Environment Research Council (NERC)
Data Activity or Cruise Information
Data Activity
| Start Date (yyyy-mm-dd) | 2005-11-01 |
| End Date (yyyy-mm-dd) | 2005-11-01 |
| Organization Undertaking Activity | Plymouth Marine Laboratory |
| Country of Organization | United Kingdom |
| Originator's Data Activity Identifier | AMT17_CTD_CTD013s |
| Platform Category | lowered unmanned submersible |
BODC Sample Metadata Report for AMT17_CTD_CTD013s
| 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 183142 | 20.00 | 1 | 1 | 303.40 | 303.70 | 300.60 | Niskin bottle | No problem reported | ||
| 183143 | 20.00 | 2 | 2 | 203.20 | 204.20 | 201.50 | Niskin bottle | No problem reported | ||
| 183144 | 20.00 | 3 | 3 | 176.40 | 176.60 | 174.50 | Niskin bottle | No problem reported | ||
| 183145 | 20.00 | 4 | 4 | 175.80 | 176.20 | 174.00 | Niskin bottle | No problem reported | ||
| 183146 | 20.00 | 5 | 5 | 127.00 | 127.60 | 125.70 | Niskin bottle | No problem reported | ||
| 183147 | 20.00 | 6 | 6 | 117.40 | 117.60 | 116.00 | Niskin bottle | No problem reported | ||
| 183148 | 20.00 | 7 | 7 | 117.60 | 117.80 | 116.20 | Niskin bottle | No problem reported | ||
| 183149 | 20.00 | 8 | 8 | 117.50 | 117.80 | 116.10 | Niskin bottle | No problem reported | ||
| 183150 | 20.00 | 9 | 9 | 117.80 | 117.80 | 116.30 | Niskin bottle | No problem reported | ||
| 183151 | 20.00 | 10 | 10 | 117.10 | 117.80 | 115.90 | Niskin bottle | No problem reported | ||
| 183152 | 20.00 | 11 | 11 | 112.50 | 112.80 | 111.10 | Niskin bottle | No problem reported | ||
| 183153 | 20.00 | 12 | 12 | 102.40 | 102.60 | 101.10 | Niskin bottle | No problem reported | ||
| 183154 | 20.00 | 13 | 13 | 51.70 | 52.20 | 50.90 | Niskin bottle | No problem reported | ||
| 183155 | 20.00 | 14 | 14 | 52.60 | 52.80 | 51.60 | Niskin bottle | No problem reported | ||
| 183156 | 20.00 | 15 | 15 | 51.90 | 52.50 | 51.10 | Niskin bottle | No problem reported | ||
| 183157 | 20.00 | 16 | 16 | 29.80 | 30.40 | 29.20 | Niskin bottle | No problem reported | ||
| 183158 | 20.00 | 17 | 17 | 29.60 | 29.80 | 28.80 | Niskin bottle | No problem reported | ||
| 183159 | 20.00 | 18 | 18 | 29.90 | 30.10 | 29.10 | Niskin bottle | No problem reported | ||
| 183160 | 20.00 | 19 | 19 | 16.50 | 16.80 | 15.80 | Niskin bottle | No problem reported | ||
| 183161 | 20.00 | 20 | 20 | 16.90 | 17.10 | 16.20 | Niskin bottle | No problem reported | ||
| 183162 | 20.00 | 21 | 21 | 16.10 | 16.60 | 15.50 | Niskin bottle | No problem reported | ||
| 183163 | 20.00 | 22 | 22 | 3.60 | 3.80 | 2.90 | Niskin bottle | No problem reported | ||
| 183164 | 20.00 | 23 | 23 | 3.60 | 4.00 | 3.00 | Niskin bottle | No problem reported | ||
| 183165 | 20.00 | 24 | 24 | 3.70 | 3.80 | 3.00 | 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.
Related Data Activity activities are detailed in Appendix 1
Cruise
| Cruise Name | D299 (AMT17) |
| Departure Date | 2005-10-15 |
| Arrival Date | 2005-11-28 |
| Principal Scientist(s) | Patrick M Holligan (University of Southampton School of Ocean and Earth 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 |
Appendix 1: AMT17_CTD_CTD013s
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 |
|---|---|---|---|---|
| 1127232 | Water sample data | 2005-11-01 06:10:00 | 27.78194 N, 38.80805 W | RRS Discovery D299 (AMT17) |
| 1788270 | Water sample data | 2005-11-01 06:10:00 | 27.78194 N, 38.80805 W | RRS Discovery D299 (AMT17) |
| 1869550 | Water sample data | 2005-11-01 06:10:00 | 27.78194 N, 38.80805 W | RRS Discovery D299 (AMT17) |
