Metadata Report for BODC Series Reference Number 1222984
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
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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
RRS James Clark Ross Cruise AMT8 (JR41) Underway Navigation and Bathymetry Data Quality Report
Bathymetry
The bathymetry channel is fairly noisy in parts with the main bathymetry baseline sometimes obscured by anomalous values. Obvious spikes have been flagged along with whole sections where the baseline bathymetry is not distinguishable from the noise. Due to the noise in the channel, care should be taken when using it. The ship docked in Ascension Island between 29/04/1999 10:30:01 and 03/05/1999 14:15:01, during this time the bathymetry channel records null values.
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
Kongsberg Simrad EA500 bathymetric echosounder
The EA500 is a bathymetric echosounder that can be used in water as deep as 10,000 m. It features triple frequency operation with a separate digitiser for each channel and high transmitted power with an instantaneous dynamic range of 160 dB. The instrument can operate with several pulses in the water simultaneously and has bottom tracking capabilities. A wide range of transducers (single beam, split beam or side-looking) is available and the ping rate is adjustable up to 10 pings per second. The split beam operation measures the athwartships inclination angle of the seabed.
This instrument was introduced in June 1989 and and replaced by the EA 600 in 2000.
Specifications
| Operational range | 1, 5, 10, 15, 25, 50, 100, 150, 250, 500, 750, 1000, 2500, 5000 and 10000 m |
| Phasing | 0 to 10000 m in 1 m increments (manual or automatic) |
| Non saturated instantaneous input range | -160 to 0 dB |
| Output power regulation | 0 to 20 dB relative to full power |
| Noise figure | 10 dB |
| Operating temperature | 0 to 55°C |
| Ping rate | max 10 pings per second (adjustable) |
Further details can be found in the manufacturer's specification sheet.
Trimble 4000DS Global Positioning System receiver
The Trimble 4000DS Differential Surveyor is similar to the 4000RS (a Maxwell-based receiver that is oriented toward precision positioning applications. It is intended for use as a DGPS base station, generating RTCM-104 corrections). The 4000Ds can apply RTCM-104 corrections to the satellite data it receives in order to generate accurate position fixes in real time.
RRS James Clark Ross Cruise AMT8 (JR41) Underway Navigation and Bathymetry Instrumentation Document
The instrumentation has been collated from various sources as historic notation of instrumentation was not well documented. Care may be required if making assumptions based on the instruments used.
The following instruments were used for navigation:
| Instrument Name | Model | Serial Number | Parameter(s) |
|---|---|---|---|
| Trimble 4000DS Global Positioning System receiver | 4000DS | N/A | Latitude and Longtiude |
| Simrad EA500 Echosounder | EA500 | N/A | Bathymetry |
RRS James Clark Ross Cruise AMT8 (JR41) Underway Navigation and Bathymetry Processing Document
Originator's Data Processing
Raw data were logged as ADC counts on the ship's computers. They were converted into engineering units using initial manufacturers' calibrations.
The data were submitted to BODC in RVS internal format for post-cruise processing and data banking.
BODC Data Processing
Reformatting
Underway data files were merged into a single binary merge file using time as the primary linking key. The time span of the file was from 23/04/1999 18:51 to 07/06/1999 08:02, with a sampling interval of 1 minute.
Screening
Each data channel was inspected on a graphics workstation and any spikes or periods of dubious data were flagged. The power of the workstation software was used to carry out comparative screening checks between channels by overlaying data channels. A map of the cruise track was simultaneously displayed in order to take account of the oceanographic context.
Data processing, correction and calibration
A program was run which located any null values in the latitude and longitude channels and checked to ensure that the ship's speed did not exceed 15 knots. The program identified 3 gaps which were filled using linear interpolation.
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 | JR19990425 (AMT8, JR41, JR42) |
| Departure Date | 1999-04-25 |
| Arrival Date | 1999-06-07 |
| Principal Scientist(s) | Nigel Rees (Plymouth Marine Laboratory), Tim A Minshull (University of Southampton School of Ocean and Earth Science) |
| 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 |
