Metadata Report for BODC Series Reference Number 1885678
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
Data quality report for CTD data from FRV Scotia cruises 0515S, 1315S and 1815S
During BODC quality control, data were screened using in house visualisation software. The data were screened and any obvious outliers and spikes were looked at in closer detail and flagged if necessary. The originator provided quality flags for all data and so minimal flags were added during BODC processing as data had already been through originator QC. The originator's flags were converted to 'L' flags during processing.
There were a number of profiles where CPHLZZXX and CPHLPR01 are negative for the duration of the cast and so the whole of these casts have been flagged 'M'.
CCOMD002
The first cycle of the series 1886252 has the value -95.292503 ppb which was flagged by the originator. During BODC processing this value was set to null.
Data Access Policy
Open 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.
If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:
"Contains public sector information licensed under the Open Government Licence v1.0."
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.
CTD data from FRV Scotia cruises 0215S, 0315S, 0515S, 0815S, 1015S, 1115S, 1315S, 1415S, 1715S and 1815S: Instrumentation
Cruise | Manufacturer | Model | Sensor | Serial Number |
---|---|---|---|---|
0215S, 0315S, 0815S | Sea-Bird | SBE 19plus V2 SEACAT | CTD | 6028 |
WETLabs | ECO-FLNTU | Combined fluorometer and turbidity sensor | 0942 | |
1015S, 1115S, 1415S, 1715S | Sea-Bird | SBE 19plus V2 SEACAT | CTD | 6029 |
WETLabs | ECO-FLNTU | Combined fluorometer and turbidity sensor | 0947 | |
0515S, 1315S, 1815S | Sea-Bird | SBE 911plus | CTD | |
Paroscientific | Digiquartz Depth sensors | Pressure | 64240 | |
Sea-Bird | SBE 3plus | Temperature | 2041 | |
Sea-Bird | SBE 4C | Conductivity | 1615 | |
Sea-Bird | SBE 43 | Dissolved Oxygen | 0504 | |
WETLabs | ECO-FLNTU | Combined fluorometer and turbidity sensor | 2542 | |
Chelsea Technologies Group | UV Aquatracka | Fluorometer | 9644 | |
WETLabs | ECO FL | Fluorometer | 3700 |
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.
Aquatracka fluorometer
The Chelsea Instruments Aquatracka is a logarithmic response fluorometer. It uses a pulsed (5.5 Hz) xenon light source discharging between 320 and 800 nm through a blue filter with a peak transmission of 420 nm and a bandwidth at half maximum of 100 nm. A red filter with sharp cut off, 10% transmission at 664 nm and 678 nm, is used to pass chlorophyll-a fluorescence to the sample photodiode.
The instrument may be deployed either in a through-flow tank, on a CTD frame or moored with a data logging package.
Further details can be found in the manufacturer's specification sheet.
WETLabs ECO FLNTU fluorescence and turbidity sensor
The Environmental Characterization Optics (ECO) Fluorometer and Turbidity (FLNTU) sensor is a dual wavelength, single-angle instrument that simultaneously determines chlorophyll fluorescence and turbidity. It is easily integrated in CTD packages and provides a reliable turbidity measurement that is not affected by Colored Dissolved Organic Matter (CDOM) concentration.
The FLNTU can operate continuously or periodically and has two different types of connectors to output the data. There are 5 other models that operate the same way as this instrument but have slight differences, as stated below:
- FLNTU(RT) - has an analog an RS-232 serial output and operates continuously, when power is supplied
- FLNTU(RT)D - similar to the FLNTU(RT) but has a depth rating of 6000 m
- FLNTUB - has internal batteries for autonomous operation
- FLNTUS - has an integrated anti-fouling bio-wiper
- FLNTUSB - has the same characteristics as the FLNTUS but with internal batteries for autonomous operation
Specifications
Temperature range | 0 to 30°C |
Depth rating | 600 m (standard) 6000 m (deep) |
Turbidity | |
Wavelength | 700 nm |
Sensitivity | 0.01 NTU |
Typical range | 0.01 to 25 NTU |
Fluorescence | |
Wavelength | 470 nm (excitation), 695 nm (emission) |
Sensitivity | 0.01 µg L-1 |
Typical range | 0.01 to 50 µg L-1 |
Linearity | 99% R2 |
Further details can be found in the manufacturer's specification sheet.
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.
BODC Processing of CTD data from FRV Scotia cruises 0215S, 0315S, 0515S, 0815S, 1015S, 1115S, 1315S, 1415S, 1715S and 1815S.
Data Processing
Data were submitted to BODC as 10 ASCII files by SFT and following BODC procedures the data were archived. The files contained all CTD casts from each of the following FRV Scotia cruises: 0215S (49 casts), 0315S (47 casts), 0515S (57 casts), 0815S (32 casts), 1015S (65 casts), 1115S (20 casts), 1315S (125 casts), 1415S (6 casts), 1715S (40 casts) and 1815S (108 casts). The data from cruises 0515S, 1315S and 1815S were also accompanied by a file of quality control flags. The header of each file contained the type of CTD used for each cruise, the sensors on the CTD and their serial numbers, an explanation of the format of the file and details of any calibrations.
The concatenated files were sub-divided into individual files for each cast using in house BODC Matlab software. The divided files were then transferred to BODC internal format using standard BODC processing procedures. The originator's variables were mapped to BODC parameter codes as follows:
Originator's Variable | Units | BODC Parameter Code | Units | Comment |
---|---|---|---|---|
Pressure | dbar | PRESPR01 | dbar | |
Temperature (edit) | °C | TEMPST01 | °C | This channel has had QC applied by the originator. |
Conductivity (edit) | mS cm-1 | CNDCST01 | S m-1 | Conversion of /10 applied. This channel has had QC applied by the originator. |
Temperature (pri) | °C | TEMPST01 | °C | Channel not transferred. The edited channel has been through originator's editing procedures and is of a better quality. |
Conductivity (pri) | mS cm-1 | CNDCST01 | S cm-1 | Channel not transferred. The edited channel has been through originator's editing procedures and is of a better quality. |
Temperature (sec) | °C | TEMPST02 | °C | Channel not transferred. The edited channel has been through originator's editing procedures and is of a better quality. |
Conductivity (sec) | mS cm-1 | CNDCST02 | S cm-1 | Channel not transferred. The edited channel has been through originator's editing procedures and is of a better quality. |
Fluorescence | μg L-1 | CPHLPR01 | mg m-3 | Equivalent units |
Turbidity | NTU | TURBXXXX | NTU | |
Oxygen | mL L-1 | DOXYZZ01 | μmol L-1 | Conversion of * 44.66 applied. Series from cruises 0515S, 1315S and 1815S only. |
Fluorescence CDOM-AQ | μg L-1 | CCOMD001 | mg m-3 | Series from cruises 0515S, 1315S and 1815S only. |
Fluorescence CDOM-WL | μg L-1 | CCOMD002 | mg m-3 | Series from cruises 1315S and 1815S only. |
PSALST01 | dimensionless | Channel derived during transfer using Fofonoff and Millard (1983). | ||
SIGTPR01 | kg m-3 | Channel derived during transfer using Fofonoff and Millard (1983). | ||
OXYSSU01 | % | Channel derived during transfer using Benson and Krause (1984) if oxygen channel is present. |
Channels that were not transferred are available on request.
Screening
Post transfer analysis and crosschecks were applied according to BODC procedures. This involved the screening of data using BODC's in house visualisation software where any suspect data were flagged but not removed.
References
Benson B.B. and Krause D., 1984. The concentration and isotopic fractionation of oxygen dissolved in freshwater and seawater in equilibrium with the atmosphere. Limnol. Oceanogr., 29(3), 620-632.
Fofonoff N.P. and Millard R.C., 1983. Algorithms for computations of fundamental properties of seawater. UNESCO Technical Papers in Marine Science No. 44, 53pp.
Originator Processing of CTD data from FRV Scotia cruises 0215S, 0315S, 0515S, 0815S, 1015S, 1115S, 1315S, 1415S, 1715S and 1815S.
Sampling Strategy
During 2015 a number of cruises occurred on the FRV Scotia were objectives covered trawl sampling, fish sampling and hydrographic sampling. As part of the hydrographic sampling numerous CTD casts were completed on each cruise. The time channel of these casts was recorded in GMT.
Cruise | Cruise Dates | Number of CTD Casts |
---|---|---|
0215S | 23 JAN 2015 - 13 FEB 2015 | 49 |
0315S | 16 FEB 2015 - 09 MAR 2015 | 47 |
0515S | 25 APR 2015 - 8 MAY 2015 | 57 |
0815S | 25 JUN 2015 - 14 JUL 2015 | 32 |
1015S | 30 JUL 2015 - 20 AUG 2015 | 65 |
1115S | 23 AUG 2015 - 3 SEPT 2015 | 20 |
1315S | 19 SEPT 2015 - 02 OCT 2015 | 125 |
1415S | 5 OCT 2015 - 16 OCT 2015 | 6 |
1715S | 18 NOV 2015 - 8 DEC 2015 | 40 |
1815S | 10 DEC 2015 -23 DEC 2015 | 108 |
Data Processing
The CTD data were processed by Marine Scotland using the Sea-Bird SeaSoft routines as recommended in the SeaSoft manual for model type Sea-Bird SBE19plus V2 SEACAT.
Pressure data were binned to 1 dbar using SeaSoft and the primary temperature and conductivity channels were adjusted to produce 'edit' channels. Marine Scotland regards the 'edit' channels as the definitive version of the data.
The adjustments consisted of a de-spiking process using Marine Scotland in-house visualisation software and, as necessary, application of a low pass filter as described in Sy (1985).
Field Calibrations
For a number of the cruises Marine Scotland used water samples collected during the CTD casts to generate a calibration equations for the conductivity and fluorescence channels. However, these calibrations were not applied to the data by the originator.
Conductivity
Cruise | Number of samples used in calibration | Calibration Equation |
---|---|---|
0215S | 98 | Calibrated Conductivity (mS cm-1) = measured conductivity x 1.000403 - 0.008508 |
0315S | 94 | Calibrated Conductivity (mS cm-1) = measured conductivity x 1.0012 - 0.0397 |
0515S | 324 | Calibrated Conductivity (mS cm-1) = measured conductivity x 0.99909 + 0.034932 |
0815S | 51 | Calibrated Conductivity (mS cm-1) = measured conductivity x 1.000135 + 0.004973 |
1015S | 108 | Calibrated Conductivity (mS cm-1) = measured conductivity x 0.998795 + 0.051757 |
1115S | 39 | Calibrated Conductivity (mS cm-1) = measured conductivity x 1.000269 - 0.006588 |
1315S | 280 | Calibrated Conductivity (mS cm-1) = measured conductivity x 0.99924 + 0.025999 |
1415S | 9 | Calibrated Conductivity (mS cm-1) = measured conductivity x 0.999563 + 0.017777 |
1715S | 73 | Calibrated Conductivity (mS cm-1) = measured conductivity x 1.002776 - 0.101829 |
1815S | 274 | Calibrated Conductivity (mS cm-1) = measured conductivity x 1 - 0.00065 |
Fluorescence
Cruise | Number of samples used in calibration | Calibration Equation |
---|---|---|
0515S | 101 | Calibrated Fluorescence (µg L-1) = measured fluorescence x 0.000889 + 0.034492 |
1315S | 102 | Calibrated Fluorescence (µg L-1) = measured fluorescence x 0.000261 + 0.3669 |
1815S | 107 | Calibrated Fluorescence (µg L-1) = measured fluorescence x 0.001304 - 0.067764 |
Reference
Sy A., 1985. An alternative editing technique for oceanographic data. Deep Sea Research, 32 (12), 1591-1599.
Project Information
No Project Information held for the Series
Data Activity or Cruise Information
Cruise
Cruise Name | 1315S |
Departure Date | 2015-09-19 |
Arrival Date | 2015-10-02 |
Principal Scientist(s) | Sarah Hughes (Marine Scotland Aberdeen Marine Laboratory) |
Ship | FRV Scotia |
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 |