Metadata Report for BODC Series Reference Number 725732
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
Data Description |
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Problem Reports
No Problem Report Found in the Database
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 Dissolved Oxygen Sensor SBE 43 and SBE 43F
The SBE 43 is a dissolved oxygen sensor designed for marine applications. It incorporates a high-performance Clark polarographic membrane with a pump that continuously plumbs water through it, preventing algal growth and the development of anoxic conditions when the sensor is taking measurements.
Two configurations are available: SBE 43 produces a voltage output and can be incorporated with any Sea-Bird CTD that accepts input from a 0-5 volt auxiliary sensor, while the SBE 43F produces a frequency output and can be integrated with an SBE 52-MP (Moored Profiler CTD) or used for OEM applications. The specifications below are common to both.
Specifications
| Housing | Plastic or titanium |
| Membrane | 0.5 mil- fast response, typical for profile applications 1 mil- slower response, typical for moored applications |
| Depth rating | 600 m (plastic) or 7000 m (titanium) 10500 m titanium housing available on request |
| Measurement range | 120% of surface saturation |
| Initial accuracy | 2% of saturation |
| Typical stability | 0.5% per 1000 h |
Further details can be found in the manufacturer's specification sheet.
Instrument Description
CTD Unit and Auxiliary Sensors
A Sea-Bird Electronics SBE25 Sealogger CTD unit was used. The CTD unit included the following sensors.
| Sensor | Manufacturer | Serial number | Calibration date |
|---|---|---|---|
| Pressure | Sea-Bird | 0583 | 2006-06-14 |
| Temperature | Sea-Bird | 4357 | 2005-11-17 |
| Conductivity | Sea-Bird | 2864 | 2005-11-17 |
| Oxygen | Sea-Bird | 0450 | 2005-05-03 |
| ECO_FL Fluorometer | Wet Labs | FLRTD-064 | 2003-11-08 |
| C-Star Transmissometer | Wet Labs | CST-704DR | 2003-08-25 |
| PAR (downwards facing) | Chelsea | 46071 | 2002-07-02 |
| PAR (upwards facing) | Chelsea | 46072 | 2002-07-02 |
Calibrations
Independent water samples were used to calibrate the CTD conductivity and fluorescence data. The following calibration values were supplied to BODC, who applied them to the data as part of the transfer process. By applying the calibrations to the fluoresence values (V) the results are chlorophyll (a) in ug/l.
| Parameter | Value of m (y=mx+c) | Value of c (y=mx+c) | Equation |
|---|---|---|---|
| Conductivity | 1.006761 | -0.264339 | C(cal) = 1.006761C(obs) - 0.264339 |
| Fluorescence | 0.009593 | -1.066200 | Chl(a) = 0.009593F(V) -1.066200 |
Sea-Bird SBE 25 SEALOGGER CTD
The SBE 25 SEALOGGER is a research-quality CTD profiling system used for coastal, estuarine and, can also be a practical option, for deep-water work. It is easily configured in the field for a wide range of auxiliary sensors. The SEALOGGER is self-powered, requires no conductive cable, and is designed for use up to 6800 meters (10,000 psia). It uses the SBE3F temperature and SBE4 conductivity sensors as well as having an external strain gauge pressure sensor. It provides pump-controlled T-C ducted flow, samples at 8 Hz, records internally and provides simultaneous real-time data via its built-in RS-232 interface.
The standard CTD unit comes with a plastic housing (rated to 600 m), although this can be replaced by aluminium housing for depths up to 6800 m.
Specifications
| Parameter | SBE 25 |
|---|---|
| Temperature | Range: -5 to +35 °C Accuracy: 0.002 °C Resolution: 0.0003 °C |
| Conductivity | Range: 0 to 7 S m-1 (0 to 70 mmho cm-1) Accuracy: 0.0003 S m-1 Resolution: 0.00004 S m-1 |
| Strain gauge pressure sensor | Range: 0 to 20, 100, 350, 600, 1000, 2000, 3500, 7000 metres (expressed in metres of deployment depth capability) Accuracy: 0.1% of full scale range Resolution: 0.015% of full scale range |
Options and accessories
Additional sensors can be attached to the CTD, including:
- Dissolved Oxygen (SBE 43 DO Sensor)
- pH (SBE 18 pH Sensor or SBE 27 pH/ORP Sensor)
- fluorescence
- radiance (PAR)
- light transmission
- optical backscatter (turbidity)
The SBE 5T titanium pump can be used in place of SBE 5P pump. Further details can be found in the manufacturer's SBE 25 instrument specification.
WETLabs ECO-FL Fluorometer
The Environmental Characterization Optics series of single channel fluorometers are designed to measure concentrations of natural and synthetic substances in water, and are therefore useful for biological monitoring and dye trace studies. Selected excitation and emission filters allow detection of the following substances: chlorophyll-a, coloured dissolved organic matter (CDOM), uranine (fluorescein), rhodamine, phycoerythrin and phycocyanin.
The ECO-FL can operate continuously or periodically and has two different types of connectors to output the data (analogue and RS-232 serial output). The potted optics block results in long term stability of the instrument and the optional anti-biofouling technology delivers truly long term field measurements.
In addition to the standard model, five variants are available, and the differences between these and the basic ECO-FL are listed below:
- FL(RT): similar to the FL but operates continuously when power is supplied
- FL(RT)D: similar model to the (RT) but has a depth rating of 6000 m
- FLB: includes internal batteries for autonomous operation and periodic sampling
- FLS: similar to FLB but has an integrated anti-fouling bio-wiper
- FLSB: similar to the FLS, but includes internal batteries for autonomous operation
Specifications
| Temperature range | 0 to 30°C |
| Depth rating | 600 m (standard) 6000 m (deep) |
| Linearity | 99 % R2 |
| Chlorophyll-a | |
| Wavelength (excitation/emission) | 470/695 nm |
| Sensitivity | 0.01 µg L-1 |
| Typical range | 0.01 to 125 µg L-1 |
| CDOM | |
| Wavelength (excitation/emission) | 370/460 nm |
| Sensitivity | 0.01 ppb |
| Typical range | 0.09 to 500 ppb |
| Uranine | |
| Wavelength (excitation/emission) | 470/530 nm |
| Sensitivity | 0.07 ppb |
| Typical range | 0.12 to 230 ppb |
| Rhodamine | |
| Wavelength (excitation/emission) | 540/570 nm |
| Sensitivity | 0.01 ppb |
| Typical range | 0.01 to 230 ppb |
| Phycoerythrin | |
| Wavelength (excitation/emission) | 540/570 nm |
| Sensitivity | 0.01 ppb |
| Typical range | 0.01 to 230 ppb |
| Phycocyanin | |
| Wavelength (excitation/emission) | 630/680 nm |
| Sensitivity | 0.15 ppt |
| Typical range | 0.15 to 400 ppt |
Further details can be found in the manufacturer's specification sheet.
WETLabs C-Star transmissometer
This instrument is designed to measure beam transmittance by submersion or with an optional flow tube for pumped applications. It can be used in profiles, moorings or as part of an underway system.
Two models are available, a 25 cm pathlength, which can be built in aluminum or co-polymer, and a 10 cm pathlength with a plastic housing. Both have an analog output, but a digital model is also available.
This instrument has been updated to provide a high resolution RS232 data output, while maintaining the same design and characteristics.
Specifications
| Pathlength | 10 or 25 cm |
| Wavelength | 370, 470, 530 or 660 nm |
| Bandwidth | ~ 20 nm for wavelengths of 470, 530 and 660 nm ~ 10 to 12 nm for a wavelength of 370 nm |
| Temperature error | 0.02 % full scale °C-1 |
| Temperature range | 0 to 30°C |
| Rated depth | 600 m (plastic housing) 6000 m (aluminum housing) |
Further details are available in the manufacturer's specification sheet or user guide.
BODC Processing
Data were received by BODC in one ASCII format file that was subsequently split into seven separate files, one for each CTD profile. The series were reformatted to the internal QXF format using BODC transfer function 340. The following table details the mapping of variables to BODC parameter codes.
| Original parameter name | Original Units | Description | BODC Parameter Code | BODC Units | Comments |
|---|---|---|---|---|---|
| Pressure | Decibars | Pressure exerted by the water column | PRESPR01 | Decibars | |
| Temperature | °C | Temperature of the water column | TEMPST01 | °C | |
| Conductivity | mS cm-1 | Electrical conductivity of the water column | CNDCST01 | S m-1 | Conversion by transfer (mS cm-1 x 0.1) |
| Salinity | Dimensionless | Practical salinity of the water column by CTD and computation using UNESCO 1983 algorithm | PSALST01 | Dimensionless | |
| Fluorescence | µg l-1 | In-situ fluorescence with manufacturer's calibrations | CPHLPM01 | mg m-3 | |
| Fluorescence | µg l-1 | In-situ fluorescence with calibration against sample data | CPHLPS01 | mg m-3 | |
| Beam attenuation | m-1 | Attenuance of the water column | ATTNZS01 | m-1 | |
| Downwelling PAR | Volts | Instrument output (voltage) by PML/Chelsea Instruments 2-pi PAR downwelling light meter | LVLTPD01 | Volts | |
| Upwelling PAR | Volts | Instrument output (voltage) by PML/Chelsea Instruments 2-pi PAR upwelling light meter | LVLTPU01 | Volts | |
| Oxygen | ml l-1 | Dissolved oxygen | DOXYPR01 | µmol l-1 | Conversion by transfer (ml l-1 x 44.6) |
Following transfer to QXF, the data were screened using BODC's in-house visualisation software, EDSERPLO. Any data considered as suspect were flagged 'M'. Flags from the originator marking suspect data were retained during transfer and flagged 'L'.
Originator's Data Processing
The raw CTD data files were processed through the SeaBird Electronics SeaSoft data processing software following standard procedures. The originators used in-house interactive visual display editing software to edit out individual spikes in the primary temperature and conductivity channels. An ASCII file was generated for each CTD cast and all files from a cruise were concatenated into one ASCII file which was submitted to BODC.
Project Information
No Project Information held for the Series
Data Activity or Cruise Information
Cruise
| Cruise Name | 1206C Part 1 |
| Departure Date | 2006-08-28 |
| Arrival Date | 2006-09-06 |
| Principal Scientist(s) | Matt Gubbins (Fisheries Research Services Aberdeen Marine Laboratory) |
| Ship | FRV Clupea |
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 |
