Metadata Report for BODC Series Reference Number 1353714
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.
AMT10 TDN, TDP, Dissolved Inorganic Nitrogen, Soluble Reactive Phosphate, Particulate 15N isotopic composition, chlorophyll a, POC and PON
Originator's Protocol for Data Acquisition and Analysis
These data originate from analysis of seawater samples collected from both CTD bottle samples and CTD samples between 12 April and 08 May 2000. TDN, DIN (Nitrate+Nitrite (NO3+NO2)), TDP and SRP (PO4) originate from analyses of samples from CTD bottles. Particulate chlorophyll-a, POC, PON and isotopic N composition samples originate from both discrete underway samples and CTD bottle samples.
For the analysis of dissolved matter, seawater samples were obtained from each depth of the 18 CTD casts deployed during AMT10. Samples were collected in 250 mL glass flasks with glass stoppers which were rinsed 3 times with sample seawater prior to sample collection. Samples were filtered through pre-combusted (450°C for 12 hours) GF/F filters. After discarding the first ~100 mL, a sample of ~100 mL seawater was collected in 150 mL flat amber medicine bottles with PTFE lined polycarbonate caps and stored at -80°C. Concentrations of nitrate and phosphate were determined using a Skalar Sanplus segmented flow nutrient autoanalyzer and standard colorimetric techniques. TDN and TDP concentrations were determined from analysis of NO3 and PO4 after ultraviolet oxidation for 2 hours using a Metrohm 705 UV digestion system. The samples were irradiated in 10 mL quartz glass tubes with graphite stoppers at a temperature of 85.C. The UV photooxidised samples were then processed through a continuous flow autoanalyser and standard colorimetric technique applied (Mahaffey et al., 2004).
Chlorophyll-a concentrations from the non-toxic seawater supply were determined by filtration of seawater (2.1 to 4.2 L) followed by onboard fluorometric analysis. POC and PON concentrations were determined using a Carlo Erba (NC 2500) elemental analyzer.
Analysis of stable nitrogen isotopic content was performed using standard elemental analyzer isotope ratio mass spectrometer (EA-IRMS) techniques. Sub-samples of freeze dried, 150 mm, glass fiber filters were randomly selected and homogenized using a pestle and mortar. The d15N PON was determined using an online system consisting of a Carlo Erba EA coupled to a Finnigan Delta CIRMS.
References Cited
Mahaffey C., Williams R.G., Wolff G.A. and Anderson W.T., 2004. Physical supply of nitrogen to phytoplankton in the Atlantic Ocean. Global biogeochemical Cycles, 18, GB1034, doi:10.1029/2003GB002129.
Instrumentation Description
Skalar Sanplus segmented flow nutrient autoanalyzer, Carlo Erba (NC 2500) elemental analyzer, Finnigan Delta CIRMS and a Metrohm 705 UV digestion system.
BODC Data Processing Procedures
Data were submitted to BODC in Microsoft Excel spreadsheet format. Sample metadata were checked against information held in the database - there was one discrepancy. For AMT10-24, the depths provided were 125 m and 150 m. As no bottle was fired at 125 m and other data files contain 150 m and 200 m entries only, the data were loaded with depths 150 m and 200 m respectively.
For 5 particulate samples, multiple depths (for example 7 + 25 m) were provided alongside one set of data. In these instances water samples from seperate depths were pooled for analyses and provided one value for the POC/N and chl-a parameters. The same data values for each parameter have been loaded for each of the sample depths that were pooled. These values have been flagged to draw attention to the data. There is one repeat sample for the particulate CTD data, the average and standard deviation have been loaded to the database. The DON and DOP data provided were not loaded to the database as they were derived from the measured variables and nutrient data.
Parameter codes defined in the BODC parameter dictionary were assigned to each variable. The data were provided in units which were consistent with those used for the relevant parameters in the BODC database. Data were 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 |
|---|---|---|---|---|---|
| mean TDN | µmol l-1 | Concentration of nitrogen (total) per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration, oxidation and colorimetric autoanalysis | NTOTWCD1 | µmol l-1 | - |
| stdev TDN | µmol l-1 | Concentration standard deviation of nitrogen (total) per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration, oxidation and colorimetric autoanalysis | SDNTWCD1 | µmol l-1 | - |
| mean TDP | µmol l-1 | Concentration of phosphorus (total) per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration, oxidation and colorimetric autoanalysis | TPHSWCD1 | µmol l-1 | - |
| stdev TDP | µmol l-1 | Concentration standard deviation of phosphorus (total) per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration, oxidation and colorimetric autoanalysis | SDTPWCD1 | µmol l-1 | - |
| mean DIN | µmol l-1 | Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis | NTRZAAD1 | µmol l-1 | - |
| stdev DIN | µmol l-1 | Concentration standard deviation of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis | SDNZAAD1 | µmol l-1 | - |
| mean SRP | µmol l-1 | Concentration of phosphate {PO4} per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis | PHOSAAD1 | µmol l-1 | - |
| stdev SRP | µmol l-1 | Concentration standard deviation of phosphate {PO4} per unit volume of the water body [dissolved plus reactive particulate <GF/F phase] by filtration and colorimetric autoanalysis | SDPHAAD1 | µmol l-1 | - |
| Chlorophyll-a | µg L-1 | Concentration of chlorophyll-a {chl-a} per unit volume of the water body [particulate >GF/F phase] by filtration, acetone extraction and fluorometry | CPHLFLP1 | mg m-3 | - |
| Chlorophyll-a std dev | µg L-1 | Concentration standard deviation of chlorophyll-a {chl-a} per unit volume of the water body [particulate >GF/F phase] by filtration, acetone extraction and fluorometry | CLSDFLP1 | mg m-3 | - |
| POC | µmol l-1 | Concentration of carbon (organic) {POC} per unit volume of the water body [particulate >GF/F phase] by filtration, acidification and elemental analysis | CORGCAP1 | µmol l-1 | - |
| POC std dev | µmol l-1 | Concentration standard deviation of carbon (organic) {POC} per unit volume of the water body [particulate >GF/F phase] by filtration, acidification and elemental analysis | SDCORGP1 | µmol l-1 | - |
| PON | µmol l-1 | Concentration of nitrogen (total) {'PON'} per unit volume of the water body [particulate >GF/F phase] by filtration and elemental analysis | NTOTCNP1 | µmol l-1 | - |
| PON std dev | µmol l-1 | Concentration standard deviation of nitrogen (total) {'PON'} per unit volume of the water body [particulate >GF/F phase] by filtration and elemental analysis | SDNTOTP1 | µmol l-1 | - |
| D15N PON | Parts per thousand | Enrichment of 15N in total nitrogen in the water body [particulate >GF/F phase] by filtration, combustion and mass spectrometry | D15NMTP1 | Parts per thousand | - |
| D15N PON std dev | Parts per thousand | Enrichment standard deviation of 15N in total nitrogen in the water body [particulate >GF/F phase] by filtration, combustion and mass spectrometry | SD15MTP1 | Parts per thousand | - |
Data Quality Report
BODC has not been advised of any QC checks performed by the data originator before submission to BODC.
For 5 particulate samples, multiple depths (for example 7 + 25 m) were provided alongside one set of data. In these instances water samples from seperate depths were pooled for analyses and provided one value for the POC/N and chl-a parameters. The same data values for each parameter have been loaded for each of the sample depths that were pooled. These values have been flagged to draw attention to the data.
Problem Report
Not relevant to this data set.
Project Information
The Atlantic Meridional Transect (AMT) - Phase 1 (1995-2000)
Who was involved in the project?
The Atlantic Meridional Transect (AMT) programme was designed by and implemented as a collaboration between Plymouth Marine Laboratory (PML) and Southampton Oceanography Centre (SOC). The programme was hosted by Plymouth Marine Laboratory and involved additional researchers from UK and international universities throughout its duration.
What was the project about?
When AMT began in 1995 the programme provided a platform for international scientific collaboration, including the calibration and validation of SeaWiFs measurements and products. The programme provided an exceptional opportunity for nationally and internationally driven collaborative research and provided a platform for excellent multi-disciplinary oceanographic research. As an in situ observation system, the data collected by the AMT consortium informed on changes in biodiversity and function of the Atlantic ecosystem during this period of rapid change to our climate and biosphere.
The scientific aims were to assess:
- mesoscale to basin scale phytoplankton processes
- the functional interpretation of bio-optical signatures
- the seasonal, regional and latitudinal variations in mesozooplankton dynamics
When was the project active?
The first phase of the AMT programme ran from 1995 to 2000 and consisted of a total of 12 cruises. A second phase of funding allowed the project to continue for the period 2002 to 2006 with a further 6 cruises.
Brief summary of the project fieldwork/data
The AMT programme undertook biological, chemical and physical oceanographic research during the annual return passage of the RRS James Clark Ross between the UK and the Falkland Islands or the RRS Discovery between the UK and Cape Town, a distance of up to 13,500 km. This transect crossed a range of ecosystems from sub-polar to tropical and from euphotic shelf seas and upwelling systems to oligotrophic mid-ocean gyres. The transect route was covered north-south in September/October and south-north in April/May of each year.
The measurements of hydrographic and bio-optical properties, plankton community structure and primary production completed on the first 12 transects (1995-2000) represent the most coherent set of repeated biogeochemical observations over ocean basin scales. This unique dataset has led to several important discoveries concerning the identification of oceanic provinces, validation of ocean colour algorithms, distributions of picoplankton, identifying new regional sinks of pCO2 and variability in rates of primary production and respiration.
Who funded the project?
The programme was funded by the Natural Environment Research Council (NERC) and further support was received from the National Aeronautics and Space Administration (NASA) with equipment and funding from the Sea-viewing Wild Field-of-view Sensor (SeaWiFS) project.
Data Activity or Cruise Information
Cruise
| Cruise Name | JR20000412 (AMT10, JR49) |
| Departure Date | 2000-04-12 |
| Arrival Date | 2000-05-08 |
| Principal Scientist(s) | Chris Gallienne (Plymouth Marine Laboratory) |
| Ship | RRS James Clark Ross |
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 |
