Metadata Report for BODC Series Reference Number 384567
Metadata Summary
Problem Reports
Data Access Policy
Narrative Documents
Project Information
Data Activity or Cruise Information
Fixed Station Information
BODC Quality Flags
Metadata Summary
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Problem Reports
The oxygen data collected on this cruise have not been calibrated against sample data and should be used with great caution.
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
Sea Bird Electronics SBE13 Dissolved Oxygen Sensor
The SBE 13 was designed as an auxiliary sensor for Sea Bird SBE 9plus, but can fitted in custom instrumentation applications. When used with the SBE 9 Underwater Unit, a flow-through plenum improves the data quality, as the pumping water over the sensor membrane reduces the errors caused by oxygen depletion during the periods of slow or intermittent flushing and also reduces exposure to biofouling.
The output voltage is proportional to membrane current (oxygen current) and to the sensor element's membrane temperature (oxygen temperature), which is used for internal temperature compensation.
Two versions of the SBE 13 are available: the SBE 13Y uses a YSI polarographic element with replaceable membranes to provide in situ measurements up to 2000 m depth and the SBE 13B uses a Beckman polarographic element to provide in situ measurements up to 10500 m depth, depending on the sensor casing. This sensor includes a replaceable sealed electrolyte membrane cartridge.
The SBE 13 instrument has been out of production since 2001 and has been superseded by the SBE 43.
Specifications
| Measurement range | 0 to 15 mL L-1 |
| Accuracy | 0.1 mL L-1 |
| Time response | 2 s at 25°C 5 s at 0°C |
| Depth range | 2000 m (SBE 13Y- housing in anodized aluminum) 6800 m (SBE 13B- housing in anodized aluminum) 105000 m (SBE 13B- housing in titanium) |
Further details can be found in the manufacturer's specification sheet.
Sea-Bird Electronics SBE 911 and SBE 917 series CTD profilers
The SBE 911 and SBE 917 series of conductivity-temperature-depth (CTD) units are used to collect hydrographic profiles, including temperature, conductivity and pressure as standard. Each profiler consists of an underwater unit and deck unit or SEARAM. Auxiliary sensors, such as fluorometers, dissolved oxygen sensors and transmissometers, and carousel water samplers are commonly added to the underwater unit.
Underwater unit
The CTD underwater unit (SBE 9 or SBE 9 plus) comprises a protective cage (usually with a carousel water sampler), including a main pressure housing containing power supplies, acquisition electronics, telemetry circuitry, and a suite of modular sensors. The original SBE 9 incorporated Sea-Bird's standard modular SBE 3 temperature sensor and SBE 4 conductivity sensor, and a Paroscientific Digiquartz pressure sensor. The conductivity cell was connected to a pump-fed plastic tubing circuit that could include auxiliary sensors. Each SBE 9 unit was custom built to individual specification. The SBE 9 was replaced in 1997 by an off-the-shelf version, termed the SBE 9 plus, that incorporated the SBE 3 plus (or SBE 3P) temperature sensor, SBE 4C conductivity sensor and a Paroscientific Digiquartz pressure sensor. Sensors could be connected to a pump-fed plastic tubing circuit or stand-alone.
Temperature, conductivity and pressure sensors
The conductivity, temperature, and pressure sensors supplied with Sea-Bird CTD systems have outputs in the form of variable frequencies, which are measured using high-speed parallel counters. The resulting count totals are converted to numeric representations of the original frequencies, which bear a direct relationship to temperature, conductivity or pressure. Sampling frequencies for these sensors are typically set at 24 Hz.
The temperature sensing element is a glass-coated thermistor bead, pressure-protected inside a stainless steel tube, while the conductivity sensing element is a cylindrical, flow-through, borosilicate glass cell with three internal platinum electrodes. Thermistor resistance or conductivity cell resistance, respectively, is the controlling element in an optimized Wien Bridge oscillator circuit, which produces a frequency output that can be converted to a temperature or conductivity reading. These sensors are available with depth ratings of 6800 m (aluminium housing) or 10500 m (titanium housing). The Paroscientific Digiquartz pressure sensor comprises a quartz crystal resonator that responds to pressure-induced stress, and temperature is measured for thermal compensation of the calculated pressure.
Additional sensors
Optional sensors for dissolved oxygen, pH, light transmission, fluorescence and others do not require the very high levels of resolution needed in the primary CTD channels, nor do these sensors generally offer variable frequency outputs. Accordingly, signals from the auxiliary sensors are acquired using a conventional voltage-input multiplexed A/D converter (optional). Some Sea-Bird CTDs use a strain gauge pressure sensor (Senso-Metrics) in which case their pressure output data is in the same form as that from the auxiliary sensors as described above.
Deck unit or SEARAM
Each underwater unit is connected to a power supply and data logging system: the SBE 11 (or SBE 11 plus) deck unit allows real-time interfacing between the deck and the underwater unit via a conductive wire, while the submersible SBE 17 (or SBE 17 plus) SEARAM plugs directly into the underwater unit and data are downloaded on recovery of the CTD. The combination of SBE 9 and SBE 17 or SBE 11 are termed SBE 917 or SBE 911, respectively, while the combinations of SBE 9 plus and SBE 17 plus or SBE 11 plus are termed SBE 917 plus or SBE 911 plus.
Specifications
Specifications for the SBE 9 plus underwater unit are listed below:
| Parameter | Range | Initial accuracy | Resolution at 24 Hz | Response time |
|---|---|---|---|---|
| Temperature | -5 to 35°C | 0.001°C | 0.0002°C | 0.065 sec |
| Conductivity | 0 to 7 S m-1 | 0.0003 S m-1 | 0.00004 S m-1 | 0.065 sec (pumped) |
| Pressure | 0 to full scale (1400, 2000, 4200, 6800 or 10500 m) | 0.015% of full scale | 0.001% of full scale | 0.015 sec |
Further details can be found in the manufacturer's specification sheet.
RRS Challenger Cruise 86/91 CTD Data Documentation
Introduction
Documentation for the CTD data collected on RRS Challenger 86/91 (November - December 1991) by the Dunstaffnage Marine Laboratory, Oban, Argyll, Scotland, UK, under the direction of D. J. Ellett.
Instrumentation and Processing
The instrument used was a Seabird 9/11 CTD, and the data were processed using the Seabird software. The manufacturer's calibrations were used. Data have been averaged to 1 decibar values.
Project Information
No Project Information held for the Series
Data Activity or Cruise Information
Cruise
| Cruise Name | CH86B |
| Departure Date | 1991-11-23 |
| Arrival Date | 1991-12-02 |
| Principal Scientist(s) | Anton Edwards (Dunstaffnage Marine Laboratory) |
| Ship | RRS Challenger |
Complete Cruise Metadata Report is available here
Fixed Station Information
Fixed Station Information
| Station Name | DML North Channel CTD Stations/Sections |
| Category | Offshore area |
| Latitude | 54° 58.52' N |
| Longitude | 5° 32.50' W |
| Water depth below MSL |
DML North Channel CTD Stations/Sections
The North Channel region, between Northern Ireland and the west coast of Scotland, has been extensively surveyed since the late 1970s (especially in the 1980s) by numerous research and government institutes. The region contains several repeated hydrographic stations, some of which collectively form transects. These repeated survey transects represent the southernmost part of a greater network of similar sections on the western Scottish continental shelf which were established by Dunstaffnage Marine Laboratory (DML).
Map of standard North Channel CTD Stations
Map produced using the GEBCO Digital Atlas.
The upwards-pointing triangles indicate the nominal positions of individual Line A stations, the single downwards-pointing triangle indicates the nominal position of the Larne - Stranraer midway station. Nominal positions of Line Y and Z stations are shown by the circles and squares respectively. Measurements made at Northern Channel CTD stations lie within a box bounded by co-ordinates 54.667° N, 6° W at the south west corner and 55.283° N, 5.083° W at the north east corner.
Nominal station details:
DML Line A: Kintyre (Scotland) - Antrim (Northern Ireland)
DML Station LS: Larne (Northern Ireland) - Stranraer (Scotland) midway station
DML Line Y: Corsewall (Stranraer, Scotland) - Sanda Island (Kintyre, Scotland)
DML Line Z: Copeland Islands (Northern Ireland) - Portpatrick (Scotland)
Other Series linked to this Fixed Station for this cruise - 384555 384579 384580 384592 384623 384635 384647 384659 384660 384672 384684 384696 384703 384727
Other Cruises linked to this Fixed Station (with the number of series) - CD10B (16) CD44 (1) CH1/85 (16) CH10/81 (4) CH10/84 (14) CH11/83 (11) CH14 (16) CH2/84 (19) CH25 (16) CH30 (16) CH4/85 (16) CH7A/83 (10) CH8/85 (16) CH86B (14) CH9 (9) CH97 (16) DSK1/86 (18) FR13/85 (14) FR13/87 (12) FR14A/87 (6) FR14B/87 (9) FR7B/86 (5) FR8/86 (14) GTH1/88 (7) LF1/89 (17) LF2/89 (16)
Fixed Station Information
| Station Name | DML Line A |
| Category | Offshore route/traverse |
DML Line A
Line A is a survey section in the North Channel between Kintyre (Scotland) and Antrim (Northern Ireland). The line comprises five fixed CTD stations, which were established as part of routine monitoring of the Scottish continental shelf by Dunstaffnage Marine Laboratory (DML). Line A was occupied during the 1980s and 1990s.
Nominal station details:
DML Line A: Kintyre (Scotland) - Antrim (Northern Ireland)
| Station | Nominal latitude | Nominal longitude | Approx. depth (m) | Comment |
|---|---|---|---|---|
| 1A | 55 17.0' N | 05 43.5' W | 50 | Southend (Kintyre) |
| 2A | 55 15.2' N | 05 47.5' W | 135 | |
| 3A | 55 13.1' N | 05 52.0' W | 125 | |
| 4A | 55 11.4' N | 05 56.0' W | 150 | |
| 5A | 55 09.5' N | 06 00.0' W | 70 | Runabay Head (Antrim) |
Other Series linked to this Fixed Station for this cruise - 384555 384579 384580 384592
Other Cruises linked to this Fixed Station (with the number of series) - CD10B (5) CH1/85 (5) CH10/81 (4) CH10/84 (1) CH11/83 (5) CH14 (5) CH2/84 (5) CH25 (5) CH30 (5) CH4/85 (5) CH7A/83 (4) CH8/85 (5) CH86B (4) CH9 (5) CH97 (5) DSK1/86 (5) FR13/85 (5) FR13/87 (3) FR14B/87 (3) FR8/86 (5) LF1/89 (5) LF2/89 (5)
Fixed Station Information
| Station Name | DML Line A Station 4A |
| Category | Offshore location |
| Latitude | 55° 11.40' N |
| Longitude | 5° 56.00' W |
| Water depth below MSL | 150.0 m |
DML Station 4A
Station 4A is one of five fixed CTD stations between Kintyre (Scotland) and Antrim (Northern Ireland), established by scientists at Dunstaffnage Marine Laboratory (DML).
Other Cruises linked to this Fixed Station (with the number of series) - CD10B (1) CH1/85 (1) CH10/81 (1) CH11/83 (1) CH14 (1) CH2/84 (1) CH25 (1) CH30 (1) CH4/85 (1) CH8/85 (1) CH9 (1) CH97 (1) DSK1/86 (1) FR13/85 (1) FR13/87 (1) FR14B/87 (1) FR8/86 (1) LF1/89 (1) LF2/89 (1)
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 |
