Metadata Report for BODC Series Reference Number 2309298
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 Cook Cruise JC062 Sea surface hydrography: Data Quality Report
The non-toxic sea water supply was unlikely to have been switched on until around 24/07/2011 10:30. Data were flagged appropriately. (BODC assessment)
Unseasonally low conductivity and salinity values were observed and flagged between 2/8/2011 07:00:08-19:46:08. Suspect values were also echoed in all other hydrography channels. The data were flagged appropriately. (BODC assessment)
Noisy conductivity and salinity between 26/7/2011 09:45:08 and 26/7/2011 13:25:08, and 31/7/2011 21:44:08 and 1/8/2011 21:02:08. Suspect data flagged appropriately. (BODC assessment)
Both the fluorimeter and transmissometer experienced high bloom conditions towards the end of the cruise resulting in high chlorophyll concentrations, low transmission and high attenuation. Fluorimeter measurements above the upper range of the sensor occurred between 24/08/2011 12:37:08 and 29/08/2011 11:35:08. Transmission appeared to be saturated between 25/08/2011 10:29:08 and 26/08/2011 16:56:08. All measurements were flagged appropriately. (BODC assessment)
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
SeaBird Digital Oceanographic Thermometer SBE38
The SBE38 is an ultra-stable thermistor that can be integrated as a remote temperature sensor with an SBE21 Thermosalinograph or an SBE 45 Micro TSG, or as a secondary temperature sensor with an SBE 16 plus, 16plus-IM, 16plus V2, 16plus-IM V2 or 19plus V2 SEACAT CTD.
Temperature is determined by applying an AC excitation to reference resistances and an ultra-stable aged thermistor. The reference resistor is a hermetically sealed VISHAY. AC excitation and ratiometric comparison using a common processing channel removes measurement errors due to parasitic thermocouples, offset voltages, leakage currents and gain errors.
The SBE38 can operate in polled sampling, where it takes one sample and transmits the data, or in continuous sampling.
Specifications
| Depth rating | up to 10500 m |
| Temperature range | -5 to 35°C |
| Initial accuracy | ± 0.001°C |
| Resolution | 0.00025°C |
| Stability | 0.001°C in 6 months |
| Response time | 500 ms |
| Self-heating error | < 200 µK |
Further details can be found in the manufacturer's specification sheet.
WET Labs WETStar Fluorometers
WET Labs WETStar fluorometers are miniature flow-through fluorometers, designed to measure relative concentrations of chlorophyll, CDOM, uranine, rhodamineWT dye, or phycoerythrin pigment in a sample of water. The sample is pumped through a quartz tube, and excited by a light source tuned to the fluorescence characteristics of the object substance. A photodiode detector measures the portion of the excitation energy that is emitted as fluorescence.
Specifications
By model:
| Chlorophyll WETStar | CDOM WETStar | Uranine WETStar | Rhodamine WETStar | Phycoerythrin WETStar | |
|---|---|---|---|---|---|
| Excitation wavelength | 460 nm | 370 nm | 485 nm | 470 nm | 525 nm |
| Emission wavelength | 695 nm | 460 nm | 530 nm | 590 nm | 575 nm |
| Sensitivity | 0.03 µg l-1 | 0.100 ppb QSD | 1 µg l-1 | - | - |
| Range | 0.03-75 µg l-1 | 0-100 ppb; 0-250 ppb | 0-4000 µg l-1 | - | - |
All models:
| Temperature range | 0-30°C |
|---|---|
| Depth rating | 600 m |
| Response time | 0.17 s analogue; 0.125 s digital |
| Output | 0-5 VDC analogue; 0-4095 counts digital |
Further details can be found in the manufacturer's specification sheet, and in the instrument manual.
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.
SeaBird MicroTSG Thermosalinograph SBE 45
The SBE45 MicroTSG is an externally powered instrument designed for shipboard measurement of temperature and conductivity of pumped near-surface water samples. The instrument can also compute salinity and sound velocity internally.
The MicroTSG comprises a platinum-electrode glass conductivity cell and a stable, pressure-protected thermistor temperature sensor. It also contains an RS-232 port for appending the output of a remote temperature sensor, allowing for direct measurement of sea surface temperature.
The instrument can operate in Polled, Autonomous and Serial Line Sync sampling modes:
- Polled sampling: the instrument takes one sample on command
- Autonomous sampling: the instrument samples at preprogrammed intervals and does not enter quiescence (sleep) state between samples
- Serial Line Sync: a pulse on the serial line causes the instrument to wake up, sample and re-enter quiescent state automatically
Specifications
| Conductivity | Temperature | Salinity | |
|---|---|---|---|
| Range | 0 to 7 Sm-1 | -5 to 35°C | |
| Initial accuracy | 0.0003 Sm-1 | 0.002°C | 0.005 (typical) |
| Resolution | 0.00001 Sm-1 | 0.0001°C | 0.0002 (typical) |
| Typical stability (per month) | 0.0003 Sm-1 | 0.0002°C | 0.003 (typical) |
Further details can be found in the manufacturer's specification sheet.
RRS James Cook Cruise JC062 Underway hydrography: Instrumentation
The following hydrographic and scientific systems were fitted:
| Sensor | Serial number | Last calibration date |
| Sea-Bird SBE 45 MicroTSG | 4548881-0231 | 1/9/2010 Calibrations applied by sensor firmware |
| Sea-Bird SBE 38 digital thermometer | 3853440-0475 | 15/3/2011 Calibrations applied by sensor firmware |
| Wet Labs WETStar fluorometer | WS3S-134 | 13/9/2010 |
| WET Labs CStar Transmissometer 25 cm path length, red (660 nm) light transmissometer | CST-114PR | 20/10/2010 |
RRS James Cook Cruise JC062 Underway hydrography: BODC processing
sbe45 and surfmet was selected for transfer into BODC format since they contained the most processed sea surface hydrography data. The TSG data (salinity, temperature and conductivity) were sourced from the sbe45 data stream as the same variables in surfmet may be delayed in time. The data was reformatted to NetCDF using BODC standard data banking procedures. The following table shows how variables within the file were mapped to appropriate BODC parameter codes:
TSG data (sbe45)
| Originator's variable | Units | Description | BODC code | BODC units | Comments |
| temp_h | Degrees Celsius | Housing temperature | TMESSG01 | Degrees Celsius | - |
| cond | S m-1 | Conductivity | CNDCSG01 | S m-1 | - |
| salin | Dimensionless | Practical salinity1 | PSALSU01 | Dimensionless | Calculated from temp_h and cond |
| sndspeed | m s-1 | Sound velocity | - | - | Derived |
| temp_r | Degrees Celsius | Hull temperature (SST) | TEMPTC01 | Degrees Celsius | - |
Other sea surface data (surfmet)
| Originator's variable | Units | Description | BODC code | BDOC units | Comments |
| temp_h | Degrees Celsius | Housing temperature | - | - | sbe45 preferred source |
| temp_r | Degrees Celsius | Hull temperature (SST) | - | - | sbe45 preferred source |
| cond | S m-1 | Conductivity | - | - | sbe45 preferred source |
| fluo | Volts | Raw fluorometer output | FVLTWS01 | Volts | - |
| trans | Volts | Raw transmissometer output | TVLTDR01 | Volts | - |
| press | hPa | Air pressure | - | - | Transferred elsewhere |
| ppar | Volts x 105 | Raw PAR sensor output (port) | - | - | Transferred elsewhere |
| spar | Volts x 105 | Raw PAR sensor output (starboard) | - | - | Transferred elsewhere |
| speed | m s-1 | Relative wind speed | - | - | Transferred elsewhere |
| direct | Degrees | Relative wind direction | - | - | Transferred elsewhere |
| airtemp | Degrees Celsius | Air temperature (dry) | - | - | Transferred elsewhere |
| humidity | Percent | Relative humidity | - | - | Transferred elsewhere |
| ptir | Volts x 105 | Raw TIR sensor output (port) | - | - | Transferred elsewhere |
| stir | Volts x 105 | Raw TIR sensor output (starboard) | - | - | Transferred elsewhere |
The following manufacturer's calibration was applied to the WETStar fluorometer (s/n WS3S-134) to derive chlorophyll-a concentration:
| CHL (µg L-1) = SF x (a - CWO) | ||||||||||||||||||||||||||||||||||||||||
where 'a' is the raw voltage output, the scale factor (SF) = 15.0 µg V-1 and the clean water offset (CWO) = 0.064 V (1 µg L-1 = 1 mg m-3)
The following manufacturer's calibrations were applied to the CStar transmissometer (s/n CST-114PR) to derive transmittance and beam attenuation:
| light transmission (%) = M x volts + B | ||||||||||||||||||||||||||||||||||||||||
where M = ( Tw / [W0 - Y0] ) (A0 - Y0) / (A1 - Y1) = 21.54243860405 and B = - M x Y1 = -1.27100387763895.
| A0 = Vair = factory voltage output in air (manufacturer factory calibration) = 4.801 A1 = current (most recent) voltage output in air = 4.801 Y0 = Vd = factory dark or zero (blocked path) voltage (manufacturer factory calibration) = 0.059 Y1 = current (most recent) dark or zero (blocked path) voltage = 0.059 W0 = Vref = factory voltage output in pure water (manufacturer factory calibration) = 4.701 Tw = % transmission in pure water = 100% | ||||||||||||||||||||||||||||||||||||||||
Then:
| Attenuance (m-1) = (-1/a) x ln(Tr) | ||||||||||||||||||||||||||||||||||||||||
where a is the pathlength in metres (=0.25 m) and Tr is the decimal transmittance (=light transmission(%)/100).
All the data were then visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag, missing data by both setting the data to an appropriate value and setting the quality control flag.
Calibration
Currently, no independent data are available for calibration against samples.
Project Information
Oceans 2025 Theme 10, Sustained Observation Activity 2: Porcupine Abyssal Plain Ocean Observatory
The NERC Delivery Plan (2005) gives priority to developing ocean observing systems to detect climate change and its impact on ecosystems. One of the most effective ways to achieve this is by fixed point time-series eulerian observatories equipped with a diverse array of physical, biological and biogeochemical sensors. The Porcupine Abyssal Plain (PAP) observatory, involving high frequency measurements of both water column and seafloor processes, is the only UK open ocean observatory which meets these criteria. The PAP site has been monitored through a variety of projects since 1989. The National Oceanography Centre, Southampton (NOCS) will manage all monitoring activities at the PAP site for Oceans 2025. Spatial context to Sustained Observation Activity (SO) 2 will be provided by the Atlantic Meridional Transects (AMT) in SO 1 and by a Continuous Plankton Recorder (CPR) route (SO 15) which pass nearby.
More detailed information on this Work Package is available at pages 9 - 11 of the official Oceans 2025 Theme 10 document: Oceans 2025 Theme 10
Weblink: http://www.oceans2025.org/
Data Activity or Cruise Information
Cruise
| Cruise Name | JC062 |
| Departure Date | 2011-07-24 |
| Arrival Date | 2011-08-29 |
| Principal Scientist(s) | Henry Ruhl (National Oceanography Centre, Southampton) |
| Ship | RRS James Cook |
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 |
