Metadata Report for BODC Series Reference Number 2207254
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 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
DY040 Underway Document
Cruise details
| Cruise | RRS Discovery DY040 |
|---|---|
| Dates | 6th December 2015 - 22nd January 2016 (UTC) |
| Principal Scientific Officer | Brian King (National Oceanography Centre) |
| Embarkation Port | Nassau, Bahamas |
| Disembarkation Port | Las Palmas, Spain |
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.
DY040 Surface Hydrography Instrumentation
Instrumentation
The sea surface hydrographical suite of sensors was fed by the pumped-seawater, non-toxic supply. The estimated depth of the seawater intake at nominal load was at 4.6 m per the cruise report.
The following surface hydrography sensors were fitted:
| Manufacturer | Model | Serial number | Last calibration date | Comments |
| Sea-Bird Thermosalinograph | SBE45 | 4548881-0229 | 25/06/2015 | Internally calibrated. |
| Sea-Bird Temperature sensor | SBE38 | 3854115-0491 | 13/08/2015 | Internally calibrated. |
| WETLabs Fluorometer | WETStar 3S | WS3S-246 | 01/09/2015 | - |
| WETLabs Transmissometer | C-Star | CST-112R | 26/06/2014 | 25 cm pathlength |
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.
DY040 Surface Hydrography Data Processing Procedures
Originator's Data Processing
The data were logged by the TECHSAS (TECHnical and Scientific sensors Acquisition System) version 5.7 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 these TECHSAS (NetCDF) sea surface hydrography files were then converted onboard to MSTAR processed files and provided to BODC and used for BODC processing. Please refer to the DY040 cruise report for more information. The originator calibrated thermosalinograph (TSG) salinity data against independent samples, in addition to removing measurements when the pumps were switched over for all sea surface hydrography parameters. These incidences have automatically been assigned BODC 'N' flags.
File delivered to BODC
| Filename | Content description | Format | Interval | Start date/time (UTC) | End date/time (UTC) | Comments |
| met_tsg_dy040_01_medav_clean_cal.nc | Sea surface temperature, thermosalinograph temperature (housing), conductivity, fluorescence, transmissivity, and practical salinity (calibrated against independent samples) | MSTAR | 1 min | 03-Dec-2015 17:39:00 | 22-Jan-2016 00:00:00 |
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:
met_tsg_dy040_01_medav_clean_cal.nc
| Originator's variable | Originator's units | Description | BODC Code | BODC Units | Unit conversion | Comments |
| trans | volts | millivolts | TVLTDR01 | volts | none | |
| fluo | volts | Surface water fluorescence | FVLTWS01 | volts | none | Units are equivalent. |
| salin_cal | pss-78 | TSG salinity calibrated against independent samples | PSALSG01 | dimensionless | none | |
| temp_h | degrees celcius | Housing water temperature | TMESSG01 | degrees celcius | none | |
| cond | milliSiemens/cm | Conductivity | CNDCSG01 | Siemens/m | /10 | milliSiemens/cm to Siemens/m |
| temp_m | degrees celcius | Remote water temperature | TEMPHU01 | degrees celcius | none |
Calibration
Field Calibrations
No field calibrations have been applied to the data by BODC, but salinity field calibrations were applied by the originator as noted above.
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 = 0.058 V, Vref = 4.623 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 = 14.5 µg/L/V and CWO = 0.053 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. All channels were of decent quality, flags were added to a period on 10th December where transmittance (and thus derived attenuation) dropped unusually following a cleaning event. These suspect data were marked by adding a BODC 'M' flag.
Project Information
The Global Ocean Ship-based Hydrographic Investigations Program (GO-SHIP) project document
The Global Ocean Ship-based Hydrographic Investigations Program (GO-SHIP) brings together scientists with interests in physical oceanography, the carbon cycle, marine biogeochemistry and ecosystems, and other users and collectors of ocean interior data to develop a sustained global network of hydrographic sections as part of the Global Ocean / Climate Observing System.
The GO-SHIP Panel was established in 2007 by the IOCCP and CLIVAR to develop a strategy for a sustained global repeat hydrography program as a contribution to the OceanObs09 Conference (September 2009) and to revise the 1994 WOCE hydrographic program manual. Based on community discussions at the OceanObs09 Conference, the Panel recommended the development of a sustained repeat hydrography program to:
- develop formal international agreements for a sustained international repeat ship-based hydrography program, including an internationally-agreed strategy and implementation plan building on the guidelines in the Community White Paper,
- advocate for national contributions to this strategy and participation in the global program,
- provide a central forum for communication and coordination, and
- develop syntheses of hydrographic data, in partnership with national, regional, and global research programs.
The IOCCP and CLIVAR International Project Offices have agreed to provide project office support to this program as it develops.
Project office support for GO-SHIP is provided by the IOC-SCOR International Ocean Carbon Coordination Project (IOCCP) and the Climate Variability and Predictability Project (CLIVAR). Major financial support for this project is provided by the U.S. National Science Foundation through a grant to UNESCO - IOC (OCE - 0715161) and a grant to the Scientific Committee on Oceanic Research (OCE - 0608600) for the IOCCP.
For more information please see the official project website at GO-SHIP
NOCS National Capability
The National Oceanography Centre Southampton National Capability focuses on long term science concerned with basin/decadal variability of the Ocean.
Data Activity or Cruise Information
Cruise
| Cruise Name | DY040 |
| Departure Date | 2015-12-06 |
| Arrival Date | 2016-01-22 |
| Principal Scientist(s) | Brian A King (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 |
