Metadata Report for BODC Series Reference Number 1094439
Metadata Summary
Problem Reports
Data Access Policy
Narrative Documents
Project Information
Data Activity or Cruise Information
Fixed Station Information
BODC Quality Flags
Metadata Summary
Data Description |
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Time Co-ordinates(UT) |
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Parameters |
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Problem Reports
No Problem Report Found in the Database
Data Quality Report - see processing documentation
Data quality information is included in the general documentation for this series. Please read.
Data Access Policy
Public domain 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.
The recommended acknowledgment is
"This study uses data from the data source/organisation/programme, provided by the British Oceanographic Data Centre and funded by the funding body."
Narrative Documents
Technicon AutoAnalyzer II (AAII)
The AAII is a segmented flow analyzer used for automated colorimetric analysis. The apparatus uses 2 mm diameter glass tubing and pumps reagents at flow rates of 2 to 3 ml s-1, producing results at a typical rate of 30 to 60 samples per hour. The system comprises an autosampler, peristaltic pump, chemistry manifold a detector and a data acquisition software.
This instrument was replaced by the AA3 in 1997 which was upgraded to the AA3 HR systems in 2006.
Specifications
| Frequency | 420 kHz |
| Beam width | 1.8° at -3 dB |
| Pulse lenght | 0.1 m |
| Acoustic range precision | ± 2.5 cm |
| Sampling rate | 1 Hz |
| Tilt accuracy | ± 0.5° |
| Tilt resolution | ± 0.01° |
| Diameter of ensonified area | 0.9 m for 30 m range 3.1 m for 100 m range 6.3 m for 200 m range |
Non-toxic (underway) sea water supply
A source of uncontaminated near-surface (commonly 3 to 7 m) seawater pumped continuously to shipboard laboratories on research vessels. There is typically a temperature sensor near the intake (known as the hull temperature) to provide measurements that are as close as possible to the ambient water temperature. The flow from the supply is typically directed through continuously logged sensors such as a thermosalinograph and a fluorometer. Water samples are often collected from the non-toxic supply. The system is also referred to as the underway supply.
AMT2 Nutrient (micromolar) measurements from underway surface samples
Originator's Protocol for Data Acquisition and Analysis
This data originates from analyses of samples taken from the ship's non-toxic supply on 158 occasions during the cruise.
Concentrations of dissolved nitrate, nitrite, phosphate and silicate were measured using a 4-channel Technicon autoanalyser. Underway samples, taken from the ship's non-toxic supply at approximately 4 hourly intervals were analysed. All 4 nutrients being successfully determined in 99.4% of the underway samples.
On the whole, the system was stable and reliable from day to day. There were some initial problems with bubble patterns at the beginning of the cruise due, in part, to the severity of the weather on leaving Port Stanley. Lubrication of the autoanalyser pumps rectified the majority of the hydraulic problems, indicating that the pump oil had dried out between AMT-1 and AMT-2 and that lubrication of the pumps and rollers should become standard procedure prior to commencing analysis on subsequent cruises. Problems with the nitrite channel persisted for a further 3 days before a constricted return line was identified. Following its replacement, no further problems were encountered.
References Cited
Instrumentation Description
Not relevant to this data set.
BODC Data Processing Procedures
Data were submitted to BODC in Microsoft Excel spreadsheet format and saved in the BODC archive with reference PML980063. Sample metadata were checked against information held in the cruise report - there was one discrepancy with what appeared to be a typing error in the Julian Day data in the originator's file. The Julian Day was given as 136 with time 12:00 but was positioned in between other JD 126 data in the original file. Also the data was the same before and after for the samples analysed during JD 126 but results in a spike on all four parameters when placed at JD 136. The data has been loaded against a sample collected at 12:15 on JD126. There were no nitrite data for 4 samples indicated by N/A in originator's file. The data were assigned parameter codes defined in BODC parameter dictionary. 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 |
|---|---|---|---|---|---|
| Nitrate+Nitrite | µmol l-1 | Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate <unknown phase] by filtration and colorimetric autoanalysis | NTRZAADZ | µmol l-1 | - |
| Nitrite | µmol l-1 | Concentration of nitrite {NO2} per unit volume of the water body [dissolved plus reactive particulate <unknown phase] by filtration and colorimetric autoanalysis | NTRIAADZ | µmol l-1 | - |
| Phosphate | µmol l-1 | Concentration of phosphate {PO4} per unit volume of the water body [dissolved plus reactive particulate <unknown phase] by filtration and colorimetric autoanalysis | PHOSAADZ | µmol l-1 | - |
| Silicate | µmol l-1 | Concentration of silicate {SiO4} per unit volume of the water body [dissolved plus reactive particulate <unknown phase] by filtration and colorimetric autoanalysis | SLCAAADZ | µmol l-1 | - |
Data Quality Report
BODC has not been advised of any data quality checks carried out by the data originator. A number of negative data values have been flagged suspect with BODC flag 'M'.
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 | JR19960422 (AMT2, JR13) |
| Departure Date | 1996-04-22 |
| Arrival Date | 1996-05-22 |
| Principal Scientist(s) | David Robins (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 |
