Metadata Report for BODC Series Reference Number 2046994
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 Discovery cruise DY103 surface hydrography quality control report
Transmissometer
The non-toxic seawater supply was turned off and the sensors cleaned at regular intervals throughout the cruise, these instances were flagged accordingly. The output from the transmissometer appeared good until a ~5 hour period on 27/06/2019, during which the output from the transmissometer was subject to spiking, and it could not be determined which data were reliable. The transmissometer is suspected to have been affected by the presence of an air bubble. All data during this period were flagged in both the attenuation and transmittance channels calculated from the output from the transmissometer. After this period the output appeared normal, with the exception of a ~4.5 hour period where the ship docked in Cork, and the non-toxic seawater supply was turned off. Data during this period were also flagged accordingly.
Data Access Policy
Open Data supplied by Natural Environment Research Council (NERC)
You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."
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.
RRS Discovery cruise DY103 surface hydrography instrumentation
Instrumentation
The sea surface hydrographical suite of sensors was fed by the pumped-seawater, non-toxic supply. The depth of the seawater intake was at 5.5 m.
The following surface hydrology sensors were fitted:
| Manufacturer | Model | Serial number | Last manufacturer's calibration date | Comments |
| WETLabs Fluorometer | WETStar | WS3S-134 | 24/10/2018 | |
| WETLabs Transmissometer | C-Star | CST-1852PR | 19/03/2018 | 25 cm pathlength |
| Sea-Bird Temperature sensor | SBE38 | 3854115-0490 | 20/09/2018 | |
| Sea-Bird Thermosalinograph | SBE45 | 4548881-0231 | 07/09/2017 |
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 Discovery cruise DY103 surface hydrography data processing procedures
Originator's Data Processing
The data were logged by the TECHSAS (TECHnical and Scientific sensors Acquisition System) version 5.11 data logging system which is the main data logging system on NMF-SS operated research vessels. Data were processed daily using the National Oceanography Centre data processing routines into NetCDF files, and this TECHSAS (NetCDF) sea surface hydrography files provided to BODC were used for BODC processing. Please refer to the cruise report for more information.
File delivered to BODC
| Filename | Content description | Format | Interval | Start date/time (UTC) | End date/time (UTC) | Comments |
| *-*-Surf-DY-SM_DY1.SURFMETv3 | Fluorescence and water transmissibility | NetCDF | 1 hz | 20-Jun-2019 14:02:51 | 09-Jul-2019 18:04:13 | - |
| *-*-SBE45-SBE45_DY1.TSG | Sea surface temperature (hull sensor), thermosalinograph temperature (housing), conductivity, practical salinity (uncalibrated) | NetCDF | 1 hz | 20-Jun-2019 14:02:52 | 09-Jul-2019 18:04:13 | - |
BODC Data Processing
The files were reformatted to BODC internal format using standard data banking procedures. The following table shows how the variables within the files were mapped to appropriate BODC parameter codes:
*-*-Surf-DY-SM_DY1.SURFMETv3
| Originator's variable | Originator's units | Description | BODC Code | BODC Units | Unit conversion | Comments |
| fluo | Volts | Fluorometer raw output | FVLTWS01 | Volts | N/A | - |
| trans | Volts | Transmissometer raw output | TVLTZZ01 | Volts | N/A | - |
| flow1 | l/min | Flow rate of ship's flow-through system | INFLTF01 | l/min | N/A | - |
*-*-SBE45-SBE45_DY1.TSG
| Originator's variable | Originator's units | Description | BODC Code | BODC Units | Unit conversion | Comments |
| temp_r | °C | Hull Sea Surface Temperature (SST) | TEMPHU01 | °C | N/A | - |
| temp_h | °C | Thermosalinograph temperature (housing) | TMESSG01 | °C | N/A | - |
| cond | s/m | Conductivity | CNDCSG01 | s/m | N/A | - |
| salin | PSU | Practical salinity (uncalibrated) | PSALSU01 | Dimensionless | N/A | - |
All the reformatted data were visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag.
Calibration
Field Calibrations
No field calibrations were applied to the data at BODC.
Manufacturers Calibrations
Transmissometer
The transmissometer voltage channel was converted to beam transmittance (beamtrans) and beam attenuation (atten) as follows:
beamtrans [%] = ([Volts - Vdark] / [Vref - Vdark])*100
atten [per m] = (-1/pathlength) * ln(beamtrans)
where Vdark = 0.004 V, Vref = 4.7 V and pathlength = 0.25 m.
Fluorometer
The fluorescence voltage channel was converted to engineering units (chla) using the following calibration:
chla [µg/L] = SF (volts - CWO)
where SF = 11.3 µg/L/V and CWO = 0.075 V.
Screening
All reformatted data were visualised using the in-house EDSERPLO software. Where calibrations had been applied, only the calibrated versions of those parameters were screened. Suspect data were marked by adding an appropriate quality control flag.
Project Information
Marine LTSS: CLASS (Climate Linked Atlantic Sector Science)
Introduction
CLASS is a five year (2018 to 2023) programme, funded by the Natural Environment Research Council (NERC) and extended until March 2024.
Scientific Rationale
The ocean plays a vital role in sustaining life on planet Earth, providing us with both living resources and climate regulation. The trajectory of anthropogenically driven climate change will be substantially controlled by the ocean due to its absorption of excess heat and carbon from the atmosphere, with consequent impacts on ocean resources that remain poorly understood. In an era of rapid planetary change, expanding global population and intense resource exploitation, it is vital that there are internationally coordinated ocean observing and prediction systems so policy makers can make sound evidence-based decisions about how to manage our interaction with the ocean. CLASS will underpin the UK contribution to these systems, documenting and understanding change in the marine environment, evaluating the impact of climate change and effectiveness of conservation measures and predicting the future evolution of marine environments. Over the five-year period CLASS will enhance the cost-effectiveness of observing systems by migrating them towards cutting edge autonomous technologies and developing new sensors. Finally, CLASS will create effective engagement activities ensuring academic partners have transparent access to NERC marine science capability through graduate training partnerships and access to shipborne, lab based and autonomous facilities, and modelling capabilities.
Data Activity or Cruise Information
Cruise
| Cruise Name | DY103 |
| Departure Date | 2019-06-21 |
| Arrival Date | 2019-07-09 |
| Principal Scientist(s) | Susan E Hartman (National Oceanography Centre, Southampton) |
| Ship | RRS Discovery |
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 |
