Metadata Report for BODC Series Reference Number 1762353
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
Fluorescence
The chlorophyll sensor for the underway system is considered suspect and care should be taken when using these data.
RRS James Clark Ross Cruise AMT24 (JR20140922) Surface Hydrography Data Quality Document
For all hydrogrpahy channels data were flagged before the underway system was turned on and after it was turned off. Obvious spikes were flagged suspect for TEMPHU01, PSALSU01 and CPHLUMTF.
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.
Turner Designs 10AU Field Fluorometer
The Turner Designs 10AU is designed for continuous-flow monitoring or discrete sample analyses of fluorescent species. A variety of optical kits with appropriate filters and lamps are available for a wide range of applications. Individual filters and lamps are also available for customised applications.
Standard optical kits include those for chlorophyll-a (extracted and/or in vivo), phycocyanin, phycoerythrin, CDOM, ammonium, rhodamine and fluorescein dye tracing, crude oil, refined oil, histamine and optical brighteners.
The instrument's light source is a 4 watt lamp and the detector is a photomultiplier tube with a standard detection range of 300-650 nm. A red-sensitive version with a detetion range of 185-970 nm is also available.
Specifications
| Operating temperature | 0 to 55°C |
| Detector | PhotoMultiplier Tube 300 to 650 nm (standard) 185 to 870 nm (Red) |
| Detection Limits: Extracted Chlorophyll-a Rhodamine WT Dye Fluorescein Dye | 0.025 µg L-1 0.01 ppb (in potable water) 0.01 ppb (in potable water) |
| Linear range: Extracted Chlorophyll-a Rhodamine WT Dye Fluorescein Dye | 0 to 250µg L-1 0 to 250 ppb 0 to 250 ppb |
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.
Litre Meter flow meter
A flow meter used to monitor water flow rates for pumped systems such as ships' continuous seawater supplies.
RRS James Clark Ross Cruise AMT24 (JR20140922) Surface Hydrography Instrument Description Document
Instrumentation
| Manufacturer | Model | Main function | Serial Number | Calibration Date |
| Seatex | Seapath 320+ | Position (Latitude and Longitude) | - | - |
| Sea Bird Electronics | SBE 45 | Temperature/Salinity of the water body | 0130 | 14/05/2014 |
| Sea Bird Electronics | SBE 38 | Temperature | 0771 | 17/03/2014 |
| Sea Bird electronics | SBE 38 | Temperature | - | - |
| Chelsea Technologies | 10 AU005 | Fluorometer | - | - |
| Wet Labs | C-Star | Transmittance | CST-1279DR | 07/09/2014 |
| Litre Meter | 05SPFA40CE | Flow rate | 05/811950 | 09/06/2011 |
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 Clark Ross Cruise AMT24 (JR20140922) Surface Hydrography Processing Document
Originator's Data Processing
The sea surface hydrography measurements were performed by a Sea Bird electronics thermosalinograph in the ship's flow through system and by a temperature sensor located near the flow through intake, at the hull. The depth of the flow through intake was 6.5 m. The data streams were logged every second to the SCS system and merged into a comma separated file format (.ACO), and the header information was stored in .TPL files.
The surface hydrography data were also logged to the oceanlogger.ACO file.
| Filename | Content Description | Format | Interval | Start Date | Start Time | End Date | End Time |
|---|---|---|---|---|---|---|---|
| seatex-gga.ACO | Latitude and Longitude | ASCII (.ACO) | 1 Hz | 11/09/2014 | 12:37:39 | 02/11/2014 | 15:47:52 |
| oceanlogger.ACO | Temperature Housing | ASCII (.ACO) | ~1 Hz | 18/09/2014 | 14:33:25 | 02/11/2014 | 15:47:00 |
| Temperature Hull Sensor x2 | |||||||
| Transmissometer | |||||||
| Conductivity | |||||||
| Salinity | |||||||
| Fluorometer | |||||||
| Sound velocity | |||||||
| Flow Meter |
BODC Data Processing
Sea surface hydrography parameters were transferred to internal BODC format and matched against BODC parameter codes, as presented in the table below. No unit conversions were applied, as the originators units were equivalent to the units of the respective BODC parameter code units assigned. BODC processing procedures included loading of data and reduction through averaging, unit conversions, visual screening and flagging of anomalous values. files were averaged to 60 second intervals.
| Originator's File | Originator's Parameter | Originator's Units | Description | BODC parameter code | BODC units | Comments and unit conversions |
|---|---|---|---|---|---|---|
| seatex-gga.ACO | lat | Degrees (+ve N) | Latitude north (WGS84) by Seatex Seapath DGPS | ALATGP01 | Degrees (+ve N) | - |
| seatex-gga.ACO | lon | Degrees (+ve E) | Longitude east (WGS84) by Seatex Seapath DGPS | ALONGP01 | Degrees (+ve N) | - |
| oceanlogger.ACO | salinity | psu | Practical salinity of the water body by thermosalinograph and computation using UNESCO 1983 algorithm and NO calibration against independent measurements. | PSALSU01 | Dimensionless | |
| - | - | - | Practical salinity of the water body by thermosalinograph and computation using UNESCO 1983 algorithm and calibration against independent measurements | PSALSG01 | Dimensionless | BODC calibrated salinity. ICALRF 7936 |
| oceanlogger.ACO | sstemp | °C | Temperature of the water body by thermosalinograph hull sensor and NO verification against independent measurements | TEMPHU01 | Degrees Celsius | - |
| Temperature of the water body by thermosalinograph hull sensor and verification against independent measurements | TEMPHG01 | Degrees Celsius | BODC calibrated temperature. ICALRF 7937- | |||
| oceanlogger.ACO | sstemp2 | °C | Temperature of the water body by thermosalinograph hull sensor (second sensor) and NO verification against independent measurements | TEMPHU02 | Degrees Celsius | Parameter used as a second sensor |
| oceanlogger.ACO | tstemp | °C | Temperature of conductivity measurement by thermosalinograph | TMESSG01 | Degrees Celsius | - |
| oceanlogger.ACO | conductivity | S m-1 | Electrical conductivity of the water body by in-situ conductivity cell | CNDCSG01 | Siemens per metre | - |
| oceanlogger.ACO | sound_velocity | m s-1 | Sound velocity in the water body by thermosalinograph and computation from temperature and salinity by unspecified algorithm | SVELSG01 | Metres per second | - |
| oceanlogger.ACO | chlorophyll | µg L-1 | Concentration of chlorophyll-a {chl-a} per unit volume of the water body [particulate phase] by through-flow fluorometer plumbed into non-toxic supply and manufacturer's calibration applied | CPHLUMTF | mg m-3 | - |
| oceanlogger.ACO | trans | 0< Tr <1 | Transmittance | POPTDR01 | Percent | * 100 |
| oceanlogger.ACO | flowrate | l/min | Flow rate through instrument | INFLTF01 | L min-1 | - |
Sample Calibrations
Temperature
The hull temperature sensor data were calibrated against the CTD temperature sensors during the cruise. The data from the hull sensor were compared with the temperature from the average of two externally mounted CTD temperature sensors at 6 decibars at corresponding measurement times. The temperature offset (CTD - Hull) were plotted against cruise day and CTD sensor temperature to identify and remove outliers. A regression analysis was run on the remaining data points and revealed a weak and insignificant relationship between the offset and CTD sensor data (R2= 0.0281; n = 65; p = 0.1819). A weak but significant relationship was found between offset and cruise time (R2 = 0.18997; n = 65; p = 0.0003).
Due to the significance between the offset and cruise time the following offset was applied to the Hull temperature sensor:
BODC ICALRF 7937 TEMPHG01 = 1.0034 * TEMPHU01 - 0.1069
Salinity
Bench salinometer discrete surface samples (at least 3 per day) collected from the non-toxic underway system during the cruise were used to create a calibration dataset for the calibration of the SBE45 TSG salinity data. The offset between the bench salinity and TSG salinity was calculated and plotted against bench salinity to identify outliers. There was a significant regression of the offset with bench salinity measurement (n = 86; R2 = 0.241; p < 0.001).
BODC ICALRF 7936 PSALSG01 = 0.9978 * PSALSU01 + 0.0588
Fluorometer
Although discrete chlorophyll samples were collected from the ship's underway system. Fluorometer values were considered unreliable. No calibration has been applied.
Project Information
No Project Information held for the Series
Data Activity or Cruise Information
Cruise
| Cruise Name | JR20140922 (AMT24, JR303) |
| Departure Date | 2014-09-22 |
| Arrival Date | 2014-11-01 |
| Principal Scientist(s) | Tim Smyth (Plymouth Marine Laboratory) |
| Ship | RRS James Clark Ross |
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 |
