Metadata Report for BODC Series Reference Number 1841128
No Problem Report Found in the Database
CTD data from cruise JR17001 Quality Report
Screening and Quality Control
During BODC quality control, data were screened using in house visualisation software. The data were screened and any obvious outliers and spikes were looked at in closer detail and flagged if necessary.
Improbable flags ('M') were applied to the CPHLPR01 channel where values were negative. There were a number of outliers in the POPTDR01 channel but it was not deemed that these outliers were anomalous and therefore did not required flagging.
This channel has been flagged where values are constant or increase with depth. The altimeter only collects good data within 100 m of the seabed and these instances of constant values or increases with depth occur more than 100 m from the seabed.
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."
Sea-Bird Dissolved Oxygen Sensor SBE 43 and SBE 43F
The SBE 43 is a dissolved oxygen sensor designed for marine applications. It incorporates a high-performance Clark polarographic membrane with a pump that continuously plumbs water through it, preventing algal growth and the development of anoxic conditions when the sensor is taking measurements.
Two configurations are available: SBE 43 produces a voltage output and can be incorporated with any Sea-Bird CTD that accepts input from a 0-5 volt auxiliary sensor, while the SBE 43F produces a frequency output and can be integrated with an SBE 52-MP (Moored Profiler CTD) or used for OEM applications. The specifications below are common to both.
|Housing||Plastic or titanium|
0.5 mil- fast response, typical for profile applications
1 mil- slower response, typical for moored applications
|Depth rating|| |
600 m (plastic) or 7000 m (titanium)
10500 m titanium housing available on request
|Measurement range||120% of surface saturation|
|Initial accuracy||2% of saturation|
|Typical stability||0.5% per 1000 h|
Further details can be found in the manufacturer's specification sheet.
Instrument Description for JR17001 CTD
CTD Unit and Auxiliary Sensors
The CTD unit comprised a Sea-Bird Electronics (SBE) 9plus underwater unit, an SBE 11 plus deck unit, a 24-way SBE 32 carousel and 24 Niskin bottles; all of which were mounted on a stainless steel 24-way CTD frame. Attached to the CTD were two SBE 3P temperature sensors, two SBE 4C conductivity sensors, one SBE 43 dissolved oxygen sensor, one QCP2350 PAR sensor, one CTG Aquatracka MKIII fluorometer, one WetLabs C-Star transmissometer, one Tritech Altimeter, one SBE35 temperature sensor and a RDI LADCP.
|Sensor unit||Model||Serial number||Full specification|
|CTD underwater unit||SBE 9plus||0707||SBE 9plus|
|CTD deck unit||SBE 11plus||0458||-|
|Carousel||SBE 32 - 24 Position Pylon||0636||SBE 32|
|Temperature sensor||SBE 3P||2705||SBE 03P|
|Temperature sensor||SBE 3P||5042||SBE 03P|
|Conductivity sensor||SBE 4C||3488||SBE 04C|
|Conductivity sensor||SBE 4C||2248*||SBE 04C|
|Dissolved oxygen sensor||SBE 43||0242||SBE 43|
|Altimeter||Tritech PA-200||10127||Tritech PA-200|
|Irradiance sensor||Biospherical QCP2350 PAR||70636||Biospherical QCP PAR sensor|
|Fluorometer||Chelsea MKIII Aquatracka||09-7324-001||Chelsea MKII Aquatracka|
|Transmissometer||WetLabs C-Star||396||WetLabs C-Star|
|Temperature sensor (Independent)||SBE 35||0024||SBE 35|
|LADCP||RDI Workhorse 300 kHz||15060**||LADCP|
* The secondary conductivity sensor was replaced during the cruise due to the output of the first sensor being spikey. The serial number of the first sensor was 2248 and the serial number of the second sensor was 2255.
** The LADCP was replaced during the cruise due to excessive file fragmentation. The LADCP was replaced by RDI Workhorse 300 kHz serial number 14897.
Sea-Bird Electronics SBE 911 and SBE 917 series CTD profilers
The SBE 911 and SBE 917 series of conductivity-temperature-depth (CTD) units are used to collect hydrographic profiles, including temperature, conductivity and pressure as standard. Each profiler consists of an underwater unit and deck unit or SEARAM. Auxiliary sensors, such as fluorometers, dissolved oxygen sensors and transmissometers, and carousel water samplers are commonly added to the underwater unit.
The CTD underwater unit (SBE 9 or SBE 9 plus) comprises a protective cage (usually with a carousel water sampler), including a main pressure housing containing power supplies, acquisition electronics, telemetry circuitry, and a suite of modular sensors. The original SBE 9 incorporated Sea-Bird's standard modular SBE 3 temperature sensor and SBE 4 conductivity sensor, and a Paroscientific Digiquartz pressure sensor. The conductivity cell was connected to a pump-fed plastic tubing circuit that could include auxiliary sensors. Each SBE 9 unit was custom built to individual specification. The SBE 9 was replaced in 1997 by an off-the-shelf version, termed the SBE 9 plus, that incorporated the SBE 3 plus (or SBE 3P) temperature sensor, SBE 4C conductivity sensor and a Paroscientific Digiquartz pressure sensor. Sensors could be connected to a pump-fed plastic tubing circuit or stand-alone.
Temperature, conductivity and pressure sensors
The conductivity, temperature, and pressure sensors supplied with Sea-Bird CTD systems have outputs in the form of variable frequencies, which are measured using high-speed parallel counters. The resulting count totals are converted to numeric representations of the original frequencies, which bear a direct relationship to temperature, conductivity or pressure. Sampling frequencies for these sensors are typically set at 24 Hz.
The temperature sensing element is a glass-coated thermistor bead, pressure-protected inside a stainless steel tube, while the conductivity sensing element is a cylindrical, flow-through, borosilicate glass cell with three internal platinum electrodes. Thermistor resistance or conductivity cell resistance, respectively, is the controlling element in an optimized Wien Bridge oscillator circuit, which produces a frequency output that can be converted to a temperature or conductivity reading. These sensors are available with depth ratings of 6800 m (aluminium housing) or 10500 m (titanium housing). The Paroscientific Digiquartz pressure sensor comprises a quartz crystal resonator that responds to pressure-induced stress, and temperature is measured for thermal compensation of the calculated pressure.
Optional sensors for dissolved oxygen, pH, light transmission, fluorescence and others do not require the very high levels of resolution needed in the primary CTD channels, nor do these sensors generally offer variable frequency outputs. Accordingly, signals from the auxiliary sensors are acquired using a conventional voltage-input multiplexed A/D converter (optional). Some Sea-Bird CTDs use a strain gauge pressure sensor (Senso-Metrics) in which case their pressure output data is in the same form as that from the auxiliary sensors as described above.
Deck unit or SEARAM
Each underwater unit is connected to a power supply and data logging system: the SBE 11 (or SBE 11 plus) deck unit allows real-time interfacing between the deck and the underwater unit via a conductive wire, while the submersible SBE 17 (or SBE 17 plus) SEARAM plugs directly into the underwater unit and data are downloaded on recovery of the CTD. The combination of SBE 9 and SBE 17 or SBE 11 are termed SBE 917 or SBE 911, respectively, while the combinations of SBE 9 plus and SBE 17 plus or SBE 11 plus are termed SBE 917 plus or SBE 911 plus.
Specifications for the SBE 9 plus underwater unit are listed below:
|Parameter||Range||Initial accuracy||Resolution at 24 Hz||Response time|
|Temperature||-5 to 35°C||0.001°C||0.0002°C||0.065 sec|
|Conductivity||0 to 7 S m-1||0.0003 S m-1||0.00004 S m-1||0.065 sec (pumped)|
|Pressure||0 to full scale (1400, 2000, 4200, 6800 or 10500 m)||0.015% of full scale||0.001% of full scale||0.015 sec|
Further details can be found in the manufacturer's specification sheet.
The Chelsea Instruments Aquatracka is a logarithmic response fluorometer. It uses a pulsed (5.5 Hz) xenon light source discharging between 320 and 800 nm through a blue filter with a peak transmission of 420 nm and a bandwidth at half maximum of 100 nm. A red filter with sharp cut off, 10% transmission at 664 nm and 678 nm, is used to pass chlorophyll-a fluorescence to the sample photodiode.
The instrument may be deployed either in a through-flow tank, on a CTD frame or moored with a data logging package.
Further details can be found in the manufacturer's specification sheet.
Biospherical Instruments QCP-2350 [underwater] PAR sensor
A cosine-corrected PAR quantum irradiance profiling sensor. For use in underwater applications with 24 bit ADC systems. Measures light available for photosynthesis on a flat surface. Operation is by a single channel compressed analog output voltage that is proportional to the log of incident PAR (400-700 nm) irradiance. The sensor is designed for operation in waters to depths of up to 2,000 m (standard) or 6,800 m (optional).
For more information, please see this document: https://www.bodc.ac.uk/data/documents/nodb/pdf/Biospherical_QCP2300_QCP2350_Apr2014.pdf
Tritech Digital Precision Altimeter PA200
This altimeter is a sonar ranging device that gives the height above the sea bed when mounted vertically. When mounted in any other attitude the sensor provides a subsea distance. It can be configured to operate on its own or under control from an external unit and can be supplied with simultaneous analogue and digital outputs, allowing them to interface to PC devices, data loggers, telemetry systems and multiplexers.
These instruments can be supplied with different housings, stainless steel, plastic and aluminum, which will limit the depth rating. There are three models available: the PA200-20S, PA200-10L and the PA500-6S, whose transducer options differ slightly.
|Beamwidth (°)||20 Conical||10 included conical beam||6 Conical|
|Operating range|| |
1 to 100 m
0.7 to 50 m
0.3 to 50 m
0.1 to 10 m
Common specifications are presented below
|Digital resolution||1 mm|
|Analogue resolution||0.25% of range|
|Depth rating||700 , 2000, 4000 and 6800 m|
|Operating temperature||-10 to 40°C|
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.
|Pathlength||10 or 25 cm|
|Wavelength||370, 470, 530 or 660 nm|
~ 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)
BODC Data Processing of CTD casts from cruise JR17001
Files from 43 of the 44 CTD casts from cruise JR17001 were processed and submitted to BODC in .nc format. The cast that was not submitted was a test cast. The files were subsequently archived and transferred to BODC internal format using standard BODC procedures. The variables provided in the files were mapped to BODC parameter codes as follows:
|Originator's Variable||Originator's Units||BODC Parameter Code||BODC Units||Comment|
|cond||mS cm-1||CNDCST01||S m-1||Conversion of * 0.1 applied.|
|fluor||µg L-1||CPHLPR01||mg m-3||Equivalent units|
|oxygen||µmol kg-1||DOXYZZ01||µmol L-1||Conversion of CTDOXY * ((sigma-T + 1000)/1000) applied.|
|par||number||IRRDUV01||µE m-2 s -1||-|
The following parameters were derived by BODC when the data were transferred to internal BODC netcdf format:
|BODC Parameter Code||BODC Units||Comment|
|OXYSZZ01||%||Derived by BODC using DOXYZZ01, TEMPST01 and PSALST01|
|POTMCV01||°C||Derived by BODC using TEMPST01, PSALST01 and PRESPR01.|
|SIGTPR01||kg m-3||Derived by BODC using POTMCV01, PSALST01 and PRESPR01.|
|TOKGPR01||L kg-1||Derived by BODC using SIGTPR01.|
The following originator's variables were not transferred to BODC internal format but are available on request:
- cond1, cond2 - the originator specfied cond as the preferred channel
- psal1, psal2 - the originator specfied psal as the preferred channel
- temp1, temp2 - the originator specfied temp as the preferred channel
- potemp, potemp1, potemp2 - the parameter is derived by BODC instead
Post transfer analysis and crosschecks were applied according to BODC procedures. This involved the screening of data using BODC's in house visualisation software where any suspect data were flagged but not removed. During screening, any data that were flagged as improbable by the originator were converted to BODC data flags.
Originator Data Processing of CTD casts from cruise JR17001
A total of 44 CTD casts were performed during JR17001 with 34 of these casts were completed as part of the ORCHESTRA programme and the remaining 10 casts completed for the NERC-CONICYT ICEBERGS programme. 20 of the ORCHESTRA casts surveyed the SR1b line.
The CTD data were acquired using Seabird SeaSave version 7.22.3. Subsequently, the following three processes were run in SBE Data Processing:
- Data conversion - converted raw data from engineering units to binary .cnv files.
- AlignCTD - applied a time alignment offset to the oxygen data relative to pressure to compensate for hysteresis effects.
- CellTM - corrected conductivity data for cell thermal mass effects.
Any settings used during these steps were provided by the manufacturer.
Data were then processed using a suite of Matlab programs developed by the Ocean Circulation and Processing group at the National Oceanography Centre (NOC).
The CTD temperature sensor was calibrated by comparison with SBE35 values obtained at the time of bottle firings. The calibration of the temperature sensors are as follows:
|Calibration equation as a function of station number, n|
|Sensor 1||tempcalib = tempraw + 0.00013n + 0.00441|
|Sensor 2||tempcalib = tempraw +0.00019n + 0.00686|
Conductivity calibrations were applied by comparing laboratory analysed values from Niskin water samples and CTD values at the time of bottle firing. The calibration of the sensors are as follows:
|Calibration equation as a function of station number, n, and pressure, p|
|Sensor 1||condcalib = condraw x (((0.007 - 0.0003n + interp([0 700 5000],[0.001 -0.0005 -0.001], p))/35 + 1)|
|Sensor 2||condcalib = condraw x (((0.0025 - 0.0001n + interp([0 400 5000],[0.0005 0.001 -0.001], p))/35 + 1)|
Dissolved oxygen calibrations were applied in post-cruise processing by comparing Winkler titration values from Niskin water samples and CTD values at the time of bottle firing.
Further information on the CTD processing can be found in section 12.2 of the cruise report.
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.
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.
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.
Three Work Packages have been funded by the ORCHESTRA programme. These are described in brief below:
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.
|Cruise Name||JR17001 (ORCHESTRA)|
|Principal Scientist(s)||Alexander Brearley (British Antarctic Survey), David Barnes (British Antarctic Survey), Yvonne L Firing (National Oceanography Centre, Southampton)|
|Ship||RRS James Clark Ross|
Complete Cruise Metadata Report is available here
No Fixed Station Information held for the Series
The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:
|<||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.)|
|E||End of CTD Down/Up Cast|
|G||Non-taxonomic biological characteristic uncertainty|
|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|
|O||Improbable value - user quality control|
|0||no quality control|
|2||probably good value|
|3||probably bad value|
|6||value below detection|
|7||value in excess|
|A||value phenomenon uncertain|
|Q||value below limit of quantification|