Metadata Report for BODC Series Reference Number 1094427
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.
AMT1 micro-molar nutrient measurements from underway surface samples
Originator's Protocol for Data Acquisition and Analysis
This data originates from analyses on underway samples collected from the ship's non-toxic supply. The seawater samples were collected at approximately 4 hourly intervals and stored in the dark at 4°C in a laboratory refrigerator and anlysed with the CTD bottle samples. Nutrient analyses for underway samples were completed within 20 hours of sampling in all cases. Clean handling techniques were employed to avoid contamination of the samples.
The main nutrient analyser was a Technicon AAII autoanalyser. The analytical chemical methodologies used were according to Brewer and Riley (1965) for nitrate and nitrite, Kirkwood (1989) for phosphate and silicate. The nitrate was measured as nitrite using a copper-cadmium reduction column to reduce nitrate to nitrite and is, therefore measured as nitrate plus nitrite.
References Cited
Brewer P.G. and Riley J.P., 1965. The automatic determination of nitrate in sea water. Deep-Sea Research, 12, 765-772.
Kirkwood D.S., 1989. Simultaneous determination of selected nutrients in seawater. ICES CM1989/C:29, 12pp.
Instrumentation Description
Not relevant to this data set.
BODC Data Processing Procedures
Data were submitted to BODC in Microsoft Excel spreadsheet format. The samples were provided with Julian Day and time (GMT) as metadata - three samples had no time provided and these data could not be loaded to the database. Sample metadata were loaded to the database. Parameter codes defined in BODC parameter dictionary were assigned to the variables. 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 |
|---|---|---|---|---|---|
| Nitrate | 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 | - |
| Nitrite | 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 | - |
| Phosphate | 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 | - |
| Silicate | 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
The dataset has been checked by the data originator - any suspect data values were removed from the data set before submission to BODC.
Samples in the database below the specified detection limits were highlighted by the originator and have been flagged accordingly.
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 | JR19950921 (AMT1, JRXX1) |
| Departure Date | 1995-09-21 |
| Arrival Date | 1995-10-24 |
| 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 |
