Metadata Report for BODC Series Reference Number 1223103
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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Problem Reports
No Problem Report Found in the Database
RRS James Clark Ross Cruise AMT11 (JR52) Underway Surface Hydrography Data Quality Report
The fluorometer remains uncalibrated but with the gain factor applied.
Further to this there are no additional known data quality issues.
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
Turner Designs 10AU Field Fluorometer
The Turner Designs 10AU is designed for continuous-flow monitoring or discrete sample analyses of fluorescent species. A variety of optical kits with appropriate filters and lamps are available for a wide range of applications. Individual filters and lamps are also available for customised applications.
Standard optical kits include those for chlorophyll-a (extracted and/or in vivo), phycocyanin, phycoerythrin, CDOM, ammonium, rhodamine and fluorescein dye tracing, crude oil, refined oil, histamine and optical brighteners.
The instrument's light source is a 4 watt lamp and the detector is a photomultiplier tube with a standard detection range of 300-650 nm. A red-sensitive version with a detetion range of 185-970 nm is also available.
Specifications
| Operating temperature | 0 to 55°C |
| Detector | PhotoMultiplier Tube 300 to 650 nm (standard) 185 to 870 nm (Red) |
| Detection Limits: Extracted Chlorophyll-a Rhodamine WT Dye Fluorescein Dye | 0.025 µg L-1 0.01 ppb (in potable water) 0.01 ppb (in potable water) |
| Linear range: Extracted Chlorophyll-a Rhodamine WT Dye Fluorescein Dye | 0 to 250µg L-1 0 to 250 ppb 0 to 250 ppb |
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 AMT11 (JR52) Underway Surface Hydrography Instrumentation Document
The instrumentation has been collated from various sources as historic notation of instrumentation was not well maintained. Care may be required if making assumptions based on the instruments used.
The following instruments were used for hydrographic measurements:
| Instrument Name | Model | Serial Number | Parameter(s) |
|---|---|---|---|
| Trimble 4000DS Global Positioning System receiver | 4000DS | N/A | Latitude and Longtiude |
| Turner 10-AU chlorophyll field fluorometer | Model 10 | N/A | Chlorophyll/Fluoresence |
| Sea-Bird SBE 21 Thermosalinograph | SBE 21 | N/A | Temperature, Conductivity/Salinity, Pressure/Depth |
RRS James Clark Ross Cruise AMT11 (JR52) Underway Surface Hydrography 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. Conductivity and two temperature channels were produced from the thermosalinograph counts using laboratory calibrations on board ship.
The data from the fluorometer was logged into the JCR Ocean Logger system using the internal A/D converter and range output.
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 13/09/2000 18:09 to 11/10/2000 10:50, with a sampling interval of 30 seconds.
Salinity was computed from housing temperature and conductivity using the UNESCO 1978 Practical Salinity Scale (Fofonoff and Millard, 1982).
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
Sample Calibrations
Temperature
The underway sea temperature channel was compared with averaged surface values extracted from CTD profiles up to 7 metres. The 46 samples gave a small offset of 0.0177 °C between CTD and surface underway data with a standard deviation of 0.0183 °C. This offset has been applied to the underway data.
Temperature(corr) °C = Temperature(raw) + 0.0177
Salinity
The underway salinity channel was compared with averaged surface values extracted from CTD profiles up to 7 metres. The 41 samples gave an offset of -0.0659 with a standard deviation of 0.0418. This offset has been applied to the underway data in order to standardise them with the CTD data.
Salinity(corr) PSU = Salinity(raw) - 0.0659 PSU
Fluorescence
The Turner Designs fluorometer operated on different range settings throughout the cruise. The points at which the range setting changed were identified during screening by looking for abrupt jumps in the signal with a magnitude of approximately 3. The data were then adjusted to a constant range for the whole cruise. For AMT11, the following corrections were applied.
| Section start | Section end | Scaling Factor |
|---|---|---|
| 13/09/2000 18:09:10 | 15/09/2000 07:03:10 | 3.16 |
| 15/09/2000 07:03:10 | 26/09/2000 02:42:40 | 31.6 |
| 26/09/2000 02:42:40 | 26/09/2000 22:37:10 | 10.0 |
| 26/09/2000 22:37:10 | 27/09/2000 08:48:40 | 3.16 |
| 27/09/2000 08:48:40 | 27/09/2000 20:29:10 | 10.0 |
| 27/09/2000 20:29:10 | 28/09/2000 11:43:10 | 3.16 |
| 28/09/2000 11:43:10 | 28/09/2000 18:36:10 | 10.0 |
| 28/09/2000 18:36:10 | 29/09/2000 11:54:10 | 3.16 |
| 29/09/2000 11:54:10 | 29/09/2000 21:02:10 | 10.0 |
| 29/09/2000 21:02:10 | 30/09/2000 00:56:10 | 3.16 |
| 30/09/2000 00:56:10 | 02/10/2000 12:20:40 | 10.0 |
| 02/10/2000 12:20:40 | 08/10/2000 19:15:40 | 31.6 |
| 08/10/2000 19:15:40 | 10/10/2000 16:55:10 | 10.0 |
| 10/10/2000 16:55:10 | 10/10/2000 19:09:10 | 3.16 |
| 10/10/2000 19:09:10 | 11/10/2000 10:50:10 | 10.0 |
At the time of processing no data were available to calibrate the fluorometer signal against chlorophyll-a concentrations.
References
Fofonoff, N.P. and Millard Jr., R.C., 1982. Algorithms for Computation of Fundamental Properties of Seawater. UNESCO Technical Papers in Marine Science, 44.
SeaBird 21 SeaCAT Thermosalinograph SBE 21
The SBE21 is an externally powered instrument used to determine sea surface temperature and conductivity from underway vessels. Data is simultaneously stored in memory and output to a computer in real-time. Typically mounted on the ship's seawater intake, the SBE21 connects to an AC-powered interface box near a computer. TH interface box provides power and an isolated data interface, and contains a NMEA 0183 port for appending navigation data. There are options for auxiliary sensors using the RS-232 interface for a SBE32 temperature sensor and for four single-ended or two differential 0-5 volt A/D input channels for voltage output auxiliary sensors.
Components include internal-field conductivity cell eliminates proximity effects, which also permits use of expendable anti-foulant devices, for long-term bio-fouling protection. The thermistor is aged and pressure-protected.
Specifications
| Conductivity | Temperature, primary | Temperature, SBE38 remote | |
|---|---|---|---|
| Range | 0 to 7 S/m | -5 to 35°C | -5 to 35°C |
| Initial Accuracy | ±0.001 S/m | ±0.01°C | ±0.001°C |
| Resolution | 0.000 S/m | 0.001°C | 0.0003°C |
More information may be found in the SBE21 brochure.
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 | JR20000912 (AMT11, JR52 Leg1, JR53) |
| Departure Date | 2000-09-12 |
| Arrival Date | 2000-10-11 |
| Principal Scientist(s) | E Malcolm S Woodward (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 |
