Metadata Report for BODC Series Reference Number 1903773
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
The underway fluorometer with serial number 1100243 was giving near zero readings constantly during the cruise. Inspection of the fluorometer onboard showed the lamp on indicator was not lit and there was water in the lamp casing due to a crack in the flow through cuvette which had been drip feeding into the lamp cavity over some time. As the instrument was under voltage throughout, there was much corrosion on all electrical contacts, and substantial corrosion on all mechanical linkages. It was deemed that this instrument was beyond on-site repair, and as such it was removed from the oceanlogger system.
An old fluorometer with serial number 6456 was in the science hold. This instrument was brought up but was found to have a very different connector for power and serial communications. The connector on 1100243 was still serviceable and was fitted to 6456 allowing underway fluorometry to continue. It was not calibrated as this required standards which were not available aboard. The LabView VI that reads the fluorometer was modified and no longer dropped out due to synch issues.
The fluorometer channel should therefore be used with caution and the data considered to be unrealistic prior to 15/01/2017 01:50. All anomalous data have been flagged.
RRS James Clark Ross Cruise JR16003 Surface Hydrography Data Quality Document
Temperature, conductivity, salinity and sound velocity
Unrealistic values in the salinity, conductivity and temperature channels were flagged as suspect. There are several instances in the time series where the surface underway system was switched off. These instances can be identified by a sudden change in values of each parameter followed by sensor drift and then a switch back to previous values. These periods of data have been flagged.
Beam transmission and attenuation
The transmittance channel was noisy and spikes in the channel have been flagged to clean up the noise. There are several instances in the time series where the surface underway system was switched off. These instances can be identified by a sudden change in transmittance values and have been flagged. Attenuation, which is derived from transmittance, has also been flagged accordingly.
Fluorescence
The fluorescence channel should be used with caution. The fluorometer records unreliable constant values of around zero throughout the majority of the cruise. On 15/01/2017 01:50:00 the fluorometer starts to display readings, however due to the unreliable nature of the current fluorometer on the JCR, caution is advised when using these data.
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.
RRS James Clark Ross Cruise JR16003 Surface Hydrography Instrument Description Document
The sea surface hydrographical suite of sensors was fed by the pumped-seawater, non-toxic supply. The seawater intake was located at 5.5 m below the sea surface. The following surface hydrology sensors were fitted:
Manufacturer | Model | Main Function | Serial number | Last calibration date |
Sea Bird Electronics | SBE45 | Thermosalinograph | 0016 | 14/05/2014 |
Sea Bird Electronics | SBE38 | Temperature x2 sensors | 0601 and 0599 | 11/06/2015 |
Chelsea Technologies | 10 AU-005 | Fluorometer | 1100243 | - |
Wet Labs | C-Star | Transmissometer | CST-396DR | 06/08/2015 |
Litremeter | 05SPFA40CE | Flow meter | 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 JR16003 Surface Hydrography Processing Procedures 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 5.5 m. The data streams were logged every second to the SCS system and merged into a comma separated file format, and logged to the Oceanlogger.ACO file. The header information was stored in the associated .TPL files.
Filename | Content Discription | Format | Interval | Start date | Start Time | End date | End Time |
oceanlogger.ACO |
| ASCII (.ACO) | ~5 seconds | 04/12/2016 | 12:45:32 | 20/01/2017 | 02:02:10 |
BODC Data Processing
The files were reformatted to BODC internal format using standard data banking procedures. All files were averaged to 60 second intervals. The following table shows how the variables within the files were mapped to appropriate BODC parameter codes:
Originator's File | Originator's Parameter | Originator's Units | Description | BODC code | BODC Units | Comments and unit conversions |
---|---|---|---|---|---|---|
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 | - |
oceanlogger.ACO | sstemp | °C | Temperature of the water body by thermosalinograph hull sensor and NO verification against independent measurements | TEMPHU01 | °C | - |
oceanlogger.ACO | sstemp2 | °C | Temperature of the water body by thermosalinograph hull sensor and NO verification against independent measurements sensor 2 | TEMPHU02 | °C | - |
oceanlogger.ACO | tstemp | °C | Temperature of conductivity measurement by thermosalinograph | TMESSG01 | °C | - |
oceanlogger.ACO | conductivity | S m-1 | Electrical conductivity of the water body by thermosalinograph | CNDCSG01 | S m-1 | - |
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 | m s-1 | - |
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 | flowrate | l min-1 | Flow rate through instrument | INFLTF01 | l min-1 | Channel dropped, available on request. |
oceanlogger.ACO | trans | % | Transmittance | POPTDR01 | % | x 100 % |
Calibrations
Manufacturers Calibrations
Transmissometer
The table below shows the Manufacturers calibration applied to the light transmittance channel.
Channel | Manufactuers Calibration equation | Coefficient Values |
Attenuance | Attenuance (m-1) = (-1/path length) x ln(decimal transmittance) | path length = 0.25 m, decimal transmittance (Tr) = light transmission (%) / 100. |
Project Information
BAS Long Term Monitoring and Survey
Introduction
The Long Term Monitoring and Survey project (LTMS) has been running since the British Antarctic Survey (BAS) was created. This project is one of the BAS core projects, with several groups of scientists collecting various types of data e.g biological, geological, atmospheric, among others.
Data collection is achievable through a wide scope of instruments and platforms, e.g. the Antarctic research stations, autonomous instrument platforms deployed on or from BAS research ships, BAS aircrafts, satellite remote sensing and others.
Scientific Objectives
This project was implemented in order to measure change and variability in the Earth system. Its long term duration allows for the monitoring of processes that could be missed in shorter term studies and experiments. The data collected is also used to check and improve the reliability of models used to stimulate and predict the behavior of the Earth system.
The main objectives are:
- Topographic survey
- Geosciences survey
- Biological survey and monitoring
- Atmospheric and oceanographic monitoring
Data Availability
The data sets obtained through this project are available to the academic community.
Data Activity or Cruise Information
Cruise
Cruise Name | JR16003 |
Departure Date | 2016-12-08 |
Arrival Date | 2017-01-19 |
Principal Scientist(s) | Sophie Fielding (British Antarctic Survey), Teal R Riley (British Antarctic Survey) |
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 |