Metadata Report for BODC Series Reference Number 1972491
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 JC159 surface hydrography quality control report
Transmissometer
The non-toxic water supply was turned off and the sensors cleaned at intervals throughout the cruise (see table below for details). The output from the transmissometer appeared good until a cleaning event on 14/03/2018, after which the output appeared to tail off 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. A successive cleaning event on 21/03/2018 did not appear to fix the problem, and the output continued to tail off following this event. All data following these two cleaning events were flagged in both the attenuation and transmittance channels calculated from the output from the transmissometer, up until a further cleaning event on 28/03/2018 which concluded at 16:06, after which the sensor readings appeared realistic.
Date | Underway Start Time | Underway Stop Time | Comments |
28/02/2018 | 22:21 | - | - |
07/03/2018 | - | 13:17 | Stopped for cleaning. |
07/03/2018 | 13:40 | - | - |
14/03/2018 | - | 14:22 | Stopped for cleaning. |
14/03/2018 | 15:05 | - | - |
21/03/2018 | - | 16:42 | Stopped for cleaning. |
21/03/2018 | 17:09 | - | - |
28/03/2018 | - | 15:20 | Stopped for cleaning. |
28/03/2018 | 16:10 | - | - |
02/04/2018 | - | 18:00 | Stopped port call at Walvis Bay, and for cleaning. |
03/04/2018 | 14:55 | - | - |
06/04/2018 | - | 12:15 | Stopped port call at Walvis Bay. |
06/04/2018 | 14:50 | - | - |
08/04/2018 | - | 07:00 | Stopped on entry to South African waters. |
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
RRS James Cook cruise JC159 underway document
Cruise details
Dates | 28th February 2018 - 11th April 2018 (UTC) |
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Principal Scientific Officer | Brian A King (National Oceanography Centre, Southampton) |
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 | |
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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 |
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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 James Cook cruise JC159 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 | 27/10/2017 | |
WETLabs Transmissometer | C-Star | CST-114PR | 19/12/2016 | 25 cm pathlength |
Sea-Bird Temperature sensor | SBE38 | 3854115-0489 | 25/10/2017 | |
Sea-Bird Thermosalinograph | SBE45 | 4548881-0485 | 28/07/2016 |
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 | |
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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 JC159 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 MSTAR data processing routines into a NetCDF file, and this TECHSAS MSTAR (NetCDF) sea surface hydrography file provided to BODC was 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 |
met_tsg_jc159_01_medav_clean_cal.nc | Fluorescence, sea surface temperature, thermosalinograph temperature (housing), conductivity, transmittance, practical salinity (uncalibrated), and practical salinity (calibrated against independent samples) | NetCDF | 60 seconds | 24/02/2018 21:29:00 | 08/04/2018 00:00:00 | - |
BODC Data Processing
The file was reformatted to BODC internal format using standard data banking procedures. The following table shows how the variables within the file were mapped to appropriate BODC parameter codes:
met_tsg_jc159_01_medav_clean_cal.nc
Originator's variable | Originator's units | Description | BODC Code | BODC Units | Unit conversion | Comments |
fluo | volts | Fluorometer raw output | FVLTWS01 | volts | N/A | - |
temp_m | °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 | - |
trans | volts | Transmissometer raw output | TVLTZZ01 | volts | N/A | - |
psal | pss-78 | Practical salinity (uncalibrated) | PSALSU01 | pss-78 | N/A | - |
psal_cal | pss-78 | Practical salinity (calibrated against independent samples) | PSALSG01 | pss-78 | 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
Practical salinity data were calibrated against discrete samples taken from the ships underway seawater supply. There were 197 samples analysed, taken approximately every four hours throughout most of the cruise. The differences between the sampled and thermosalinograph (TSG) salinities were compared using MATLAB script mtsg_bottle_compare.m where they were smoothed using a three-step filtering procedure. The resulting smooth curve was added to the TSG salinities, with the offsets applied ranging from -0.015 to -0.022 psu over time, resulting in a post-calibration residual with zero mean and a standard deviation of 0.0015 psu.
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 = 4.667 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 = 11.6 µg/L/V and CWO = 0.050 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
Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports (ORCHESTRA)
The Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports (ORCHESTRA) is a £8.4 million, five year (2016-2021) research programme funded by the Natural Environment Research Council (NERC). The aim of the research is to to advance the understanding of, and capability to predict, the Southern Ocean's impact on climate change via its uptake and storage of heat and carbon. The programme will significantly reduce uncertainties concerning how this uptake and storage by the ocean influences global climate, by conducting a series of unique fieldwork campaigns and innovative model developments.
Background
ORCHESTRA represents the first fully-unified activity by NERC institutes to address these challenges, and will draw in national and international partners to provide community coherence, and to build a legacy in knowledge and capability that will transcend the timescale of the programme itself.
It brings together science teams from six UK research institutions to investigate the role that the Southern Ocean plays in our changing climate and atmospheric carbon draw-down. It is led by British Antarctic Survey, in partnership with National Oceanography Centre, British Geological Survey, Plymouth Marine Laboratory, the Centre for Polar Observation and Modelling and the Sea Mammal Research Unit.
The oceans around Antarctica play a critical a key role in drawing down and storing large amounts of carbon and vast quantities of heat from from the atmosphere. Due to its remoteness and harsh environment, the Southern Ocean is the world's biggest data desert, and one of the hardest places to get right in climate models. The ORCHESTRA programme will make unique and important new measurements in the Southern Ocean using a range of techniques, including use of the world-class UK research vessel fleet, and deployments of innovative underwater robots. The new understanding obtained will guide key improvements to the current generation of computer models, and will enhance greatly our ability to predict climate into the future.
The scope of the programme includes interaction of the Southern Ocean with the atmosphere, exchange between the upper ocean mixed layer and the interior and exchange between the Southern Ocean and the global ocean.
Further details are available on the ORCHESTRA page.
Participants
Six different organisations are directly involved in research for ORCHESTRA. These institutions are:
- British Antarctic Survey (BAS)
- National Oceanography Centre (NOC)
- Plymouth Marine Laboratory (PML)
- British Geological Survey (BGS)
- Centre for Polar Observation and Modelling (CPOM)
- Sea Mammal Research Unit (SMRU)
GO-SHIP are a third party organisation that, although not directly involved with the programme, will conduct ship based observations that will also be used by ORCHESTRA.
Research details
Three Work Packages have been funded by the ORCHESTRA programme. These are described in brief below:
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Work Package 1: Interaction of the Southern ocean with the atmosphere
WP1 will use new observations of surface fluxes and their controlling parameters in order to better constrain the exchanges of heat and carbon loss across the surface of the Southern Ocean. -
Work Package 2: Exchange between the upper ocean mixed layer and the interior.
This work package will combine observationally-derived data and model simulations to determine and understand the exchanges between the ocean mixed layer and its interior. -
Work Package 3: Exchange between the Southern Ocean and the global ocean .
This WP will use budget analyses of the hydrographic/tracer sections to diagnose the three-dimensional velocity field of the waters entering, leaving and recirculating within the Southern Atlantic sector of the Southern ocean. -
Fieldwork and data collection
The campaign consists of 12 core cruises on board the NERC research vessels RRS James Clark Ross and RRS James Cook and will include hydrographic/tracer sections conducted across Drake Passage (SR1b), the northern Weddell Sea/Scotia Sea (A23), the northern rim of the Weddell Gyre (ANDREXII) and across the South Atlantic (24S). Section I6S will be performed by GO-SHIP Project Partners. Measurements will include temperature, salinity, dissolved oxygen, velocity, dissolved inorganic carbon, total alkalinity, inorganic nutrients, oxygen and carbon isotopes, and underway meteorological and surface ocean observations including pCO2.
Tags will be deployed on 30 Weddel seals and these will provide temperature and salinity profiles that can be used alongside the Argo data.
Autonomous underwater ocean gliders will conduct multi-month missions and will deliver data on ocean stratification, heat content, mixed layer depth and turbulent mixing over the upper 1 km, with previously-unobtainable temporal resolution. These gliders will be deployed in the Weddell Gyre and the ACC.
Field campaigns with the MASIN meteorological aircrafts will be conducted flying out of Rothera and Halley research stations and the Falkland Islands. These campaigns will deliver information on key variables relating to air-sea fluxes (surface and air temperature, wind, humidity, atmospheric CO2, radiation, turbulent fluxes of heat, momentum and CO2), in different sea ice conditions and oceanic regimes.
Eart Observation datasets will be used to inform the programme on the properties of the ocean, sea ice and atmosphere and on interactions between them.
A cluster of 6 deep ocean moorings in the Orkney Passage will collect year round series of AABW temperatre and transport. This work connects to the NERC funded project Dynamics of the Orkney Passage Outflow (DYNOPO).
The UK Earth System model (UKESM) and underlying physical model will be used to conduct analyses of heat and carbon uptake and transport by the Southern Ocean and their links to wider climate on decadal timescales.
An eddy-resolving (1/12°) sector model of the ocean south of 30°S with 75 vertical levels, will be built using the NEMO model coupled to the Los Alamos sea ice (CICE) model. The improvements on the ocean boundary layer will be based from the results from the NERC-funded OSMOSIS project and the inclusion of tides.
20-5 year runs of an adjoint model will be conducted to determine how key forcings and model states affect the uptake and subduction of heat and carbon by the ocean.
Data Activity or Cruise Information
Cruise
Cruise Name | JC159 |
Departure Date | 2018-02-28 |
Arrival Date | 2018-04-10 |
Principal Scientist(s) | Brian A King (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 |
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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 |
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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 |