Metadata Report for BODC Series Reference Number 936001


Metadata Summary

Data Description

Data Category CTD or STD cast
Instrument Type
NameCategories
Sea-Bird SBE 43 Dissolved Oxygen Sensor  dissolved gas sensors
Chelsea Technologies Group Aquatracka fluorometer  fluorometers
Sea-Bird SBE 911plus CTD  CTD; water temperature sensor; salinity sensor
Benthos PSA-916T Sonar Altimeter  altimeters
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Ms Mary Woodgate-Jones
Originating Organization National Oceanography Centre, Southampton
Processing Status banked
Project(s) CLIVAR
Oceans 2025
Oceans 2025 Theme 1
Oceans 2025 Theme 1 WP1.3
 

Data Identifiers

Originator's Identifier CTD_JC031_023_2DB
BODC Series Reference 936001
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2009-02-12 08:35
End Time (yyyy-mm-dd hh:mm) 2009-02-12 09:45
Nominal Cycle Interval 2.0 decibars
 

Spatial Co-ordinates

Latitude 60.07040 S ( 60° 4.2' S )
Longitude 68.18940 W ( 68° 11.4' W )
Positional Uncertainty Unspecified
Minimum Sensor Depth 6.93 m
Maximum Sensor Depth 3497.97 m
Minimum Sensor Height 4.03 m
Maximum Sensor Height 3495.07 m
Sea Floor Depth 3502.0 m
Sensor Distribution Variable common depth - All sensors are grouped effectively at the same depth, but this depth varies significantly during the series
Sensor Depth Datum Approximate - Depth is only approximate
Sea Floor Depth Datum Approximate - Depth is only approximate
 

Parameters

BODC CODE Rank Units Short Title Title
ACYCAA01 1 Dimensionless Record_No Sequence number
AHSFZZ01 1 Metres Height Height above bed in the water body
CNDCST01 1 Siemens per metre CTDCond Electrical conductivity of the water body by CTD
CNDCST02 1 Siemens per metre CTDCond2 Electrical conductivity of the water body by CTD (sensor 2)
CPHLPM01 1 Milligrams per cubic metre chl-a_water_ISfluor_manufctrcal_sensor1 Concentration of chlorophyll-a {chl-a CAS 479-61-8} per unit volume of the water body [particulate >unknown phase] by in-situ chlorophyll fluorometer and manufacturer's calibration applied
DEPHPR01 1 Metres CmpDep Depth below surface of the water body by profiling pressure sensor and converted to seawater depth using UNESCO algorithm
DOXYSC01 1 Micromoles per litre WC_dissO2_calib Concentration of oxygen {O2 CAS 7782-44-7} per unit volume of the water body [dissolved plus reactive particulate phase] by Sea-Bird SBE 43 sensor and calibration against sample data
PRESPR01 1 Decibars Pres_Z Pressure (spatial co-ordinate) exerted by the water body by profiling pressure sensor and corrected to read zero at sea level
PSALCC01 1 Dimensionless P_sal_CTD_calib Practical salinity of the water body by CTD and computation using UNESCO 1983 algorithm and calibration against independent measurements
PSALCC02 1 Dimensionless P_sal_CTD_calib2 Practical salinity of the water body by CTD (second sensor) and computation using UNESCO 1983 algorithm and calibration against independent measurements
TEMPCU01 1 Degrees Celsius Uncal_CTD_Temp Temperature of the water body by CTD and NO verification against independent measurements
TEMPCU02 1 Degrees Celsius Uncal_CTD_Temp2 Temperature of the water body by CTD (second sensor) and NO verification against independent measurements
TOKGPR01 1 Litres per kilogram Vol2MassCTD Conversion factor (volume to mass) for the water body by CTD and computation of density (in-situ potential temperature surface pressure) reciprocal from pressure, temperature and salinity
 

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

Problem Reports

Measurements made by the secondary conductivity sensor (CNDCST02) from stations 13-84 should be used with caution. This is because the data exhibited a slight pressure trend and poor stability. The data originator's have indicated that the primary data (CNDCST01, TEMPCU01, PSALCC01) should be used in preference.

Data Quality Report

Removal of PAR Sensors

The originators reported that up-welling (UWIRPP01) and down-welling (DWIRPP01) PAR sensors were removed from CTD casts performed in the dark and casts greater than 600 m in depth. The presence/absence of sensors was judged for each CTD cast in turn at BODC. Subsequently, DWIRPP01 and UWIRPP01 were deleted from series where is was clear the sensors had been removed.

Data Quality Report

Low negative values (Chlorophyll-a)

The manufacturer's calibrations applied to the Chelsea MKIII Aquatracka fluorometers did not offset to exactly zero, resulting in low negative values at zero signal. The low negative values are typically less than the accuracy of the instrument but have been flagged suspect because they have fallen below the parameter code limit.


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

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.

Specifications

Housing Plastic or titanium
Membrane

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 .

Benthos Programmable Sonar Altimeter (PSA) 916 and 916T

The PSA 916 is a submersible altimeter that uses the travel time of an acoustic signal to determine the distance of the instrument from a target surface. It provides the user with high resolution altitude or range data while simultaneously outputting data through a digital serial port. A wide beam angle provides for reliable and accurate range measurements under the most severe operational conditions. The instrument is electronically isolated to eliminate any potential signal interference with host instrument sensors. The PSA 916 is an upgrade of the PSA 900.

The standard model (PSA 916) has an operational depth range of 0 - 6000 m, while the titanium PSA 916T has a depth range of 0 - 10000 m. All other specifications for the two versions are the same.

Specifications

Transmit frequency 200 kHz
Transmit pulse width 250 µs
Beam pattern 14° conical
Pulse repetition rate

internal selection: 5 pps

external selection: up to 5 pps- user controlled

Range

100 m full scale

1.0 m guaranteed minimum

0.8 m typical

Range

1 cm for RS232 output

2.5 cm for analog output

Operating depth 6000 m (PSA 916) or 10000 m (PSA 916T)

Further details can be found in the manufacturer's specification sheets for the PSA 916 and the PSA 916T .

Instrument Description

CTD Unit and Auxiliary Sensors

Two CTD packages were used during RRS James Cook cruise 31 (JC031). The first CTD package (stations 1-12) comprised a Sea-Bird 911 plus CTD system, auxiliary sensors and Sea-Bird SBE 32, 24-way carousel fitted to a stainless steel frame with fin. During it's recovery at station 12 (08/02/2009), the package was pulled into the hydroboom block resulting in the total loss of the CTD package over the side. Consequently, the entire package was replaced (see below). A full description of the package is as follows:

Instrument/Sensor Serial Number Manufacturer's
Calibration Date
Comments
Sea-Bird SBE 9 plus underwater unit (aluminium) 09P-24680-0636    
Sea-Bird SBE 11 plus deck unit 11P-34173-0676    
Sea-Bird SBE 3P temperature sensor (aluminium) 03P-4301 4-Apr-08 primary (frame-mounted)
Sea-Bird SBE 4C conductivity sensor (titanium) 04C-3153(T) 22-Apr-08 primary (frame-mounted)
Sea-Bird SBE 3P temperature sensor (aluminium) 03P-4490 4-Apr-08 secondary (fin-mounted)
Sea-Bird SBE 4C conductivity sensor (titanium) 04C-3153(T) 22-Apr-08 secondary (fin-mounted)
Digiquartz temperature compensated pressure sensor 83008 10-Sep-08  
Sea-Bird SBE 32 24-way carousel 32-45661-0621    
20L OTE external spring water samplers     rosette positions 1-24
Sea-Bird SBE 43 dissolved oxygen sensor (titanium) 43-1196 3-Oct-08  
Chelsea MKIII Aquatracka fluorometer (titanium) 88108 9-Jan-08 configured for chl- a
Chelsea MKII Alphatracka transmissometer (titanium) 161045 8-Sep-05 660nm, 25cm path
Wetlabs BBRTD backscatter sensor (titanium) 115R 13-May-08 660nm
PML 2-pi PAR sensor (upwelling) 9 21-Jun-08 only fitted on casts <600m in daylight hours
PML 2-pi PAR sensor (downwelling) 10 14-Apr-08 only fitted on casts <600m in daylight hours
RDI Workhorse Monitor 300kHz ADCP (titanium) 10629   downward-looking master configuration
Benthos PSA-916T 200kHz altimeter (titanium) 1040 Mar-03  
NMF 10kHz pinger B5    
Sea-Bird SBE 5T submersible pump (titanium) 05T-4166   primary
Sea-Bird SBE 5T submersible pump (titanium) 05T-2793   secondary (fin-mounted)

The replacement CTD package (stations 13-84) also comprised a Sea-Bird 911 plus CTD system, auxiliary sensors and Sea-Bird SBE 32, 24-way carousel fitted to a stainless steel frame with fin. The LADCP (s/n 4275) was damaged during the deployment of station 35 and was replaced prior to station 36. A full description of this package is as follows:

Instrument/Sensor Serial Number Manufacturer's
Calibration Date
Comments
Sea-Bird SBE 9 plus underwater unit (titanium) 09P-24680-0637(T)    
Sea-Bird SBE 11 plus deck unit (titanium) 11P-34173-0676    
Sea-Bird SBE 3P temperature sensor (titanium) 03P-4592(T) 28-May-08 primary (frame-mounted)
Sea-Bird SBE 4C conductivity sensor (titanium) 04C-3272(T) 13-Jun-08 primary (frame-mounted)
Sea-Bird SBE 3P temperature sensor (aluminium) 03P-4782 17-Jun-08 secondary (fin-mounted)
Sea-Bird SBE 4C conductivity sensor (aluminium) 04C-3258 6-Jun-08 secondary (fin-mounted)
Digiquartz temperature compensated pressure sensor (titanium) 79501 22-Sep-08  
Sea-Bird SBE 32, 24-way carousel 32-19817-0243    
20L OTE external spring water samplers     rosette positions 21-24
10L OTE external spring water samplers     rosette positions 1-20
Sea-Bird SBE 43 dissolved oxygen sensor (titanium) 43-0619 11-Nov-08  
Chelsea MKIII Aquatracka fluorometer (titanium) 88244 10-Jun-08 configured for chl- a
Chelsea MKII Alphatracka transmissometer (titanium) 07-6075-001 18-Oct-07 660nm, 25cm path
Wetlabs BBRTD backscatter sensor (titanium) 182 20-Jun-07 660nm
PML 2-pi PAR upwelling sensor 9 21-Jun-08 only used on casts <600m and in daylight
PML 2-pi PAR downwelling sensor 10 14-Apr-08 only used on casts <600m and in daylight
RDI Workhorse Monitor 300kHz LADCP (aluminium) 4275   downward-looking master configuration (stations 13-35)
RDI Workhorse Monitor 300kHz LADCP (titanium) 10607   downward-looking master configuration (stations 36-84)
Benthos PSA-916T 200kHz altimeter (titanium) 41302 26-Apr-07  
Sea-Bird SBE 5T submersible pump (titanium) 05T-3002   primary
Sea-Bird SBE 5T submersible pump (titanium) 05T-4513   secondary (fin-mounted)

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.

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.

Additional sensors

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

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 .

Aquatracka fluorometer

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 .

BODC Processing

The data arrived at BODC in 84 MSTAR NetCDF format files. These represented all of the CTD casts taken during the cruise. The files did not include transmissometer or backscatter data as this was not processed by the originators. The files were reformatted to the internal QXF format using transfer function 445. Due to a pressure trend on the primary conductivity sensor, the PSO and data originator for the cruise have indicated that the secondary temperature, conductivity and salinity sensors should be used in preference to the primary sensors for stations 1-12. In addition, they have indicated that the primary sensors should be used in preference to secondary sensors for stations 13-84 because of a slight pressure trend and the poor stability of the secondary conductivity sensor at these stations. For these reasons, the files were transferred to QXF format in two groupings - stations 1-12 and stations 13-84. For stations 1-12, the secondary sensors were mapped to '*01' BODC parameter codes while the primary sensors were mapped to '*02' BODC parameter codes. For stations 13-84, the primary sensors were mapped to '*01' parameter codes instead. The following table shows how the variables of station 1-12 were mapped to appropriate BODC parameter codes:

Originator's Variable Units Description BODC Parameter Code Units Comment
pumps - pump status (=1 when pump on) - - Not transferred - not environmental variable
press decibar Pressure sensor PRESPR01 decibar  
pressure_temp deg C (ITS-90) pressure sensor electronics temperature - - Not transferred - not environmental variable
temp deg C (ITS-90) primary temperature sensor (frame-mounted) TEMPCU02 deg C (ITS-90)  
cond mS/cm primary conductivity sensor (frame-mounted) CNDCST02 S/m cond divided by 10
temp2 deg C (ITS-90) secondary temperature sensor (fin-mounted) TEMPCU01 deg C (ITS-90) To be used in preference to primary sensor
cond2 mS/cm secondary conductivity sensor (fin-mounted) CNDCST01 S/m cond2 divided by 10
To be used in preference to primary sensor
oxygen µmol/kg dissolved oxygen sensor DOXYSC01 µmol/l µmol/kg * ((sigma-theta + 1000)/1000)
Density was calculated from PRESPR01, TEMPCU01 and CNDCST01 using Fofonoff and Millard (1983) algorithm
altimeter metres depth from sea floor AHSFZZ01 metres  
nbf - number of CTD bottles fired - - Not transferred - not environmental variable
par_uplook W/m 2 down-welling PAR sensor DWIRPP01 W/m 2  
par_downlook W/m 2 up-welling PAR sensor UWIRPP01 W/m 2  
fluo µg/l chlorophyll- a concentration CPHLPM01 mg/m 3 1 µg/l = 1 mg/m 3
psal pss-78 practical salinity derived from press, cond and temp PSALCC02 pss-78  
psal2 pss-78 practical salinity derived from press, cond2 and temp2 PSALCC01 pss-78 To be used in preference to salinity from primary sensors
depth metres depth of CTD calculated from press and latitude DEPHPR01 metres  
potemp deg C (ITS-90) potential temperature derived from press, psal and temp - - Not transferred - can be calculated from PRESPR01, PSALCC02 and TEMPCU02
potemp2 deg C (ITS-90) potential temperature derived from press, psal2, temp2 - - Not transferred - can be calculated from PRESPR01, PSALCC01 and TEMPCU01

The following table shows how the variables of stations 13-84 were mapped to appropriate BODC parameter codes:

Originator's Variable Units Description BODC Parameter Code Units Comment
pumps - pump status (=1 when pump on) - - Not transferred - not environmental variable
press decibar Pressure sensor PRESPR01 decibar  
pressure_temp deg C (ITS-90) pressure sensor electronics temperature - - Not transferred - not environmental variable
temp deg C (ITS-90) primary temperature sensor (frame-mounted) TEMPCU01 deg C (ITS-90) To be used in preference to secondary sensor
cond mS/cm primary conductivity sensor (frame-mounted) CNDCST01 S/m cond divided by 10
To be used in preference to secondary sensor
temp2 deg C (ITS-90) secondary temperature sensor (fin-mounted) TEMPCU02 deg C (ITS-90)  
cond2 mS/cm secondary conductivity sensor (fin-mounted) CNDCST02 S/m cond2 divided by 10
oxygen µmol/kg dissolved oxygen sensor DOXYSC01 µmol/l µmol/kg * ((sigma-theta + 1000)/1000)
Density was calculated from PRESPR01, TEMPCU01 and CNDCST01 using Fofonoff and Millard (1983) algorithm
altimeter metres depth from sea floor AHSFZZ01 metres  
nbf - number of CTD bottles fired - - Not transferred - not environmental variable
par_uplook W/m 2 down-welling PAR sensor DWIRPP01 W/m 2  
par_downlook W/m 2 up-welling PAR sensor UWIRPP01 W/m 2  
fluo µg/l chlorophyll- a concentration CPHLPM01 mg/m 3 1 µg/l = 1 mg/m 3
psal pss-78 practical salinity derived from press, cond and temp PSALCC01 pss-78 To be used in preference to salinity from secondary sensors
psal2 pss-78 practical salinity derived from press, cond2 and temp2 PSALCC02 pss-78  
depth metres depth of CTD calculated from press and latitude DEPHPR01 metres  
potemp deg C (ITS-90) potential temperature derived from press, psal and temp - - Not transferred - can be calculated from PRESPR01, PSALCC01 and TEMPCU01
potemp2 deg C (ITS-90) potential temperature derived from press, psal2, temp2 - - Not transferred - can be calculated from PRESPR01, PSALCC02 and TEMPCU02

To enable the oxygen unit conversion from µmol/kg to µmol/l, the parameter TOKGPR01 (density reciprocal) was created in the output QXF files.

The reformatted data were then visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag. Missing data were marked by both setting the data to an appropriate value and setting the quality control flag.

Reference

Fofonoff N.P. and Millard Jr. R.C., 1983. Algorithms for computations of fundamental properties of seawater. UNESCO Technical Papers in Marine Science, 44, 53pp.

Originator's Data Processing

Sampling Strategy

The aim of JC031 was to occupy repeats of hydrographic sections in Drake Passage. The sections studied are as follows: Section SR1 (also known as A21), which is located in Drake Passage between the Southern tip of South America and the West Antarctic Peninsula; section SR1b is located further to the east. In addition to the previous section of SR1b, extra stations were sampled on the northern side of the Burdwood Bank, located south of the Falkland Islands. The data collected during JC031 comprised physical, chemical and biological measurements. There were five main scientific teams, physics, nutrients and oxygen, carbon, CFC's and transient tracers, and biology (phytoplankton). The data will contribute to the current knowledge of the physical, chemical and biological properties in this region, and will also allow comparisons to be drawn with previous cruise data so that the change in water properties and transport through Drake Passage from west to east can be observed.

A total of 84 CTD (conductivity-temperature-depth) casts were performed during the cruise. Of these casts, 48 (stations 2-49) were taken along the SR1 transect and 35 casts (stations 50-84) were taken along the SR1b transect. A 24-bottle rosette was used to take water samples at CTD stations with the general aim of sampling the full water column. Also mounted on the frame was a LADCP (lowered acoustic doppler current profiler), fluorometer, transmissometer, PAR and a dissolved oxygen sensor. Station 1 was a test cast, allowing scientists to practice sampling. At station 12, the CTD package ran into the blocks and the CTD was lost. CTD data were collected but there were no water samples or LADCP data from this station. Consequently, station 13 was a test cast with the new package (max wire out ~100m). The CTD cast was aborted at station 34 due to loss of communications at the start of the upcast. The cast was also aborted at station 35 when electrical termination flooded at 936m on the downcast. Station 36 was a successful repeat of stations 35 and 34.

Data Processing

Initial data processing was performed on a PC using the Seabird processing software SBE Data Processing, Version 7.18. Further information about Sea-Bird processing can be found in section 1 (p1) of the technical report for this cruise. After initial processing with the Seabird routines, all data were run through MSTAR MEXEC processing, which consisted of a suite of NOCS-generated programs. This was performed in Matlab and used NetCDF file formats to store all data. Further information about MEXEC processing can be found in sections 2, 3 and 4 (from p2-6) of the technical report from this cruise.

Field Calibrations

Salinity

CTD salinity was calibrated against independent bottle samples. Bottle samples were taken from all unique depths on every CTD cast. They were analysed using a Guildline 8400B Autosal. Further information about the collection and analysis of salinity bottle samples can be found here . Further information about the calibration of CTD salinity can be found in section 2.3 on page 3 of the technical report for this cruise.

Oxygen

CTD oxygen was calibrated against independent bottle samples. Bottle samples were taken from every CTD niskin bottle that had been fired and was sampled for other analyses. Samples were analysed using the Winkler whole bottle titration method with amperometric endpoint detection. Further information about the collection and analysis of independent bottles samples can be found here . Further information about the calibration of CTD oxygen can be found in section 2.4 (pages 4-5) of the technical report for this cruise.

Chlorophyll- a

The fluorescence sensor was not calibrated with independent bottle samples. Chlorophyll- a bottle samples were collected during the cruise but for purposes other than CTD fluorescence sensor calibration. Consequently, it may be possible to calibrate the sensor should these samples become available at a later date.


Project Information

Climate Variability and Predictability (CLIVAR)

CLIVAR is an international research programme investigating climate variability and predictability on different time-scales and the response of the climate system to anthropogenic forcing. Climate variability, its extremes and possible future changes, has a strong impact on mankind. CLIVAR seeks to better understand and predict our climate in order to take precautions and to reduce impacts of climate variability and change on our planet. CLIVAR is one of the major components of the World Climate Research Programme (WCRP). It started in 1995 and will have a lifetime of 15 years.

The specific objectives of CLIVAR are:

Further information may be obtained from the Official CLIVAR Project web site and theBODC web site


Oceans 2025 - The NERC Marine Centres' Strategic Research Programme 2007-2012

Who funds the programme?

The Natural Environment Research Council (NERC) funds the Oceans 2025 programme, which was originally planned in the context of NERC's 2002-2007 strategy and later realigned to NERC's subsequent strategy (Next Generation Science for Planet Earth; NERC 2007).

Who is involved in the programme?

The Oceans 2025 programme was designed by and is to be implemented through seven leading UK marine centres. The marine centres work together in coordination and are also supported by cooperation and input from government bodies, universities and other partners. The seven marine centres are:

Oceans2025 provides funding to three national marine facilities, which provide services to the wider UK marine community, in addition to the Oceans 2025 community. These facilities are:

The NERC-run Strategic Ocean Funding Initiative (SOFI) provides additional support to the programme by funding additional research projects and studentships that closely complement the Oceans 2025 programme, primarily through universities.

What is the programme about?

Oceans 2025 sets out to address some key challenges that face the UK as a result of a changing marine environment. The research funded through the programme sets out to increase understanding of the size, nature and impacts of these changes, with the aim to:

In order to address these aims there are nine science themes supported by the Oceans 2025 programme:

In the original programme proposal there was a theme on health and human impacts (Theme 7). The elements of this Theme have subsequently been included in Themes 3 and 9.

When is the programme active?

The programme started in April 2007 with funding for 5 years.

Brief summary of the programme fieldwork/data

Programme fieldwork and data collection are to be achieved through:

The data is to be fed into models for validation and future projections. Greater detail can be found in the Theme documents.


Oceans 2025 Theme 1: Climate, Ocean Circulation and Sea Level

Through fieldwork, analysis and modelling, Theme 1 will provide detailed knowledge of how the Atlantic, Arctic and Southern Oceans are responding to, and driving, climate change. In combination with geodetic studies, it will also improve our ability to predict global sea level and UK land movements in the century ahead.

The official Oceans 2025 documentation for this Theme is available from the following link: Oceans 2025 Theme 1

Weblink: http://www.oceans2025.org/


Oceans 2025 Theme 1, Work Package 1.3: Physical-biogeochemical budgets and mixing in the Southern Ocean

This Work Package is run by the National Oceanography Centre, Southampton (NOCS) and aims to establish regional budgets of heat, freshwater and carbon, and to develop more accurate parameterisations for predictive ocean models by quantitatively investigating diapycnal and isopycnal transport processes using observations.

Vast, though poorly quantified, amounts of anthropogenic CO2 (~20 Pg) are believed to have been absorbed into the Antarctic mode and intermediate waters. Much of this uptake is achieved in the Antarctic Circumpolar Current (ACC), involving the upwelling of North Atlantic Deep Water, its northward transport by a delicate balance between Ekman drift and eddies, followed by subduction as mode waters. Models suggest that the rate of CO2 uptake is sensitive to changes in the wind and to changes to the eddy fluxes (Mignone et al., 2005).

To predict climate change, it is essential that the size of this carbon sink be known, and the processes that control it be understood. Even the exchanges of heat and freshwater between the Atlantic and Southern Oceans are poorly known. NOCS will combine observations and modelling to quantify and understand the processes controlling property fluxes and trends in the Atlantic sector of the Southern Ocean, where the Atlantic overturning circulation is partially closed as it meets the ACC. The observational effort will be fully integrated with the international Climate Variability and Predictability (CLIVAR)/Carbon repeat hydrography program, and with the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) initiative to study mixing rates and processes; this work has been accepted as a contribution to the International Polar Year. The budgets and mixing rates inferred from field measurements will be used to both evaluate and improve numerical models.

More detailed information on this Work Package is available at pages 10 - 11 of the official Oceans 2025 Theme 1 document: Oceans 2025 Theme 1

Weblink: http://www.oceans2025.org/

References

Mignone B., Gnanadesikan A., Sarmiento JL., and Slater RD., 2005. Central role of Southern Hemisphere winds and eddies in modulating the oceanic uptake of anthropogenic carbon, Geophys Res Lett, 32 doi:101029/2005Gl024464


Data Activity or Cruise Information

Cruise

Cruise Name JC031
Departure Date 2009-02-03
Arrival Date 2009-03-03
Principal Scientist(s)Elaine McDonagh (National Oceanography Centre, Southampton)
Ship RRS James Cook

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameDrake Passage - WOCE SR1
CategoryOffshore route/traverse

World Ocean Circulation Experiment (WOCE) Southern Repeat Section 1 - South America to West Antarctic Peninsula

WOCE established a repeat hydrographic section across Drake Passage and designated it SR1 (also known as A21). The section is located between the Southern tip of South America and the West Antarctic Peninsula within a bounding box of 55° 19.40' S, 68° 15.80' W (North-Western corner) and 64° 8.52' S, 63° 4.80' W (South-Eastern corner).

A table of cruises which occupied SR1 is presented below with links to the relevant cruise reports (where available).

Cruise Country Start Date End Date
R/V Meteor 11/5 Germany 23-01-1990 08-03-1990
Polarstern ANT 10-5 Germany 08-08-1992 26-09-1992
R/V Vidal Gormaz 20VDSR0193_1 Chile 02-11-1993 25-12-1993
R/V Vidal Gormaz 20VDSR0194_1 Chile 08-11-1994 08-12-1994
R/V Vidal Gormaz 20VDSR0195_1 Chile 04-12-1995 15-12-1995
R/V Vidal Gormaz 20VDSR0196_1 Chile 28-11-1996 13-12-1996
R/V Vidal Gormaz 20VDSR0198_1 Chile 26-11-1998 15-12-1998
RRS James Clark Ross JR40 United Kingdom 15-03-1999 22-04-1999
RRS James Cook JC031 United Kingdom 03-02-2009 03-03-2009
RRS James Cook JC054 United Kingdom 28-11-2010 08-01-2011
RRS James Cook JC069 United Kingdom 31-01-2012 22-03-2012

Other Series linked to this Fixed Station for this cruise - 912096 912103 912115 912127 912139 912140 912152 912164 912176 912188 912207 912219 912220 912232 912244 912256 912268 912281 912293 912300 912312 912324 912336 912348 912361 912373 912385 912397 912404 912416 912428 912441 912453 912465 912477 912489 912490 912508 912521 912533 912545 912557 912569 912570 912582 912594 912987 912999 913002 913014 913026 913038 913051 913063 913075 913087 913099 913106 913118 913131 913143 913155 913167 913179 913180 913192 913211 913223 913235 913247 913259 913260 913272 913284 913296 913303 913315 913327 913339 913340 913352 913364 913376 913388 913407 913419 913420 913432 913444 913456 913468 913481 935789 935790 935808 935821 935833 935845 935857 935869 935870 935882 935894 935901 935913 935925 935937 935949 935950 935962 935974 935986 935998 936013 936025 936037 936049 936050 936062 936074 936086 936098 936105 936117 936129 936130 936142 936154 936166 936178 936191 936209 936210 936222 936234 936246 936258 936271 936283 1022017 1022030

Other Cruises linked to this Fixed Station (with the number of series) - JC054 (UKD-2) (45) JC069 (UKD-3) (8) JR19950320 (JR10) (128) JR20110409 (JR276, UKD-2.5) (13)

Fixed Station Information

Station NameDrake Passage
CategoryOffshore area
Latitude59° 0.00' S
Longitude62° 0.00' W
Water depth below MSL

Drake Passage

The World Ocean Circulation Experiment (WOCE, 1990-1998) was a major international experiment which made measurements and undertook modelling studies of the deep oceans in order to provide a much improved understanding of the role of ocean circulation in changing and ameliorating the Earth's climate.

The Drake Passage is the narrowest constriction of the Antarctic Circumpolar Current (ACC) - the largest current in the world and connects all three major oceanic basins both horizontally and vertically, thus being a key control in the global overturning circulation.Within the Drake Passage, two repeat hydrographic sections (SR1 and SR1b) were established by WOCE. These were designed to extend measurements collected earlier by the International Southern Ocean Studies (ISOS) programme and have continued beyond the WOCE time-frame.

The original section was SR1 (which also covers part of the A21 one time survey track). Subsequently, the section was shifted to the east (and designated SR1b) in order for it to lie on a satellite ground track as illustrated in the image below.

BODC image

In addition to the hydrographic measurements, UK research in Drake Passage also includes a network of coastal and deep tide gauges, analysis of satellite altimeter data, and state-of-the-art global numerical modeling.

Other Series linked to this Fixed Station for this cruise - 912096 912103 912115 912127 912139 912140 912152 912164 912176 912188 912207 912219 912220 912232 912244 912256 912268 912281 912293 912300 912312 912324 912336 912348 912361 912373 912385 912397 912404 912416 912428 912441 912453 912465 912477 912489 912490 912508 912521 912533 912545 912557 912569 912570 912582 912594 912601 912613 912625 912637 912649 912650 912662 912674 912686 912698 912705 912717 912729 912730 912742 912754 912766 912778 912791 912809 912810 912822 912834 912846 912858 912871 912883 912895 912902 912914 912926 912938 912951 912963 912987 912999 913002 913014 913026 913038 913051 913063 913075 913087 913099 913106 913118 913131 913143 913155 913167 913179 913180 913192 913211 913223 913235 913247 913259 913260 913272 913284 913296 913303 913315 913327 913339 913340 913352 913364 913376 913388 913407 913419 913420 913432 913444 913456 913468 913481 913493 913500 913512 913524 913536 913548 913561 913573 913585 913597 913604 913616 913628 913641 913653 913665 913677 913689 913690 913708 913721 913733 913745 913757 913769 913770 913782 913794 913801 913813 913825 913837 913849 913850 935789 935790 935808 935821 935833 935845 935857 935869 935870 935882 935894 935901 935913 935925 935937 935949 935950 935962 935974 935986 935998 936013 936025 936037 936049 936050 936062 936074 936086 936098 936105 936117 936129 936130 936142 936154 936166 936178 936191 936209 936210 936222 936234 936246 936258 936271 936283 936295 936302 936314 936326 936338 936351 936363 936375 936387 936399 936406 936418 936431 936443 936455 936467 936479 936480 936492 936511 936523 936535 936547 936559 936560 936572 936584 936596 936603 936615 936627 936639 936640 936652 936664 1022017 1022029 1022030 1022042

Other Cruises linked to this Fixed Station (with the number of series) - JC041 (UKD-1) (66) JC054 (UKD-2) (146) JC069 (UKD-3) (24) JR16002 (61) JR19931120 (JR00a) (30) JR19941113 (JR0B) (29) JR19961128 (JR16) (29) JR20000113 (JR47) (29) JR20001121 (JR55) (32) JR20021224 (JR81) (32) JR20031211 (JR94) (30) JR20041201 (JR111, JR115) (35) JR20050124 (JR112, JR113) (5) JR20060216 (JR136, JR137) (1) JR20061206 (JR155, JR163, JR164) (1) JR20071129 (JR171, JR193, JR196 Leg1, JR212) (32) JR20091118 (JR195, JR198) (33) JR20101205 (JR242) (9) JR20110409 (JR276, UKD-2.5) (65) JR20130317 (JR252B, JR272B, JR273A, JR281, UKD-4) (175) JR20140309 (JR293 Leg1, JR299 Leg1, UKD-5) (21) JR20150110 (JR305, JR306) (1) RATS/CTD100 (1) RATS/CTD103 (1) RATS/CTD106 (1) RATS/CTD108 (1) RATS/CTD111 (1) RATS/CTD113 (1) RATS/CTD115 (1) RATS/CTD120 (1) RATS/CTD122 (1) RATS/CTD124 (1) RATS/CTD126 (1) RATS/CTD129 (1) RATS/CTD131 (1) RATS/CTD133 (1) RATS/CTD136 (1) RATS/CTD138 (1) RATS/CTD140 (1) RATS/CTD142 (1) RATS/CTD145 (1) RATS/CTD147 (1) RATS/CTD150 (1) RATS/CTD151 (1) RATS/CTD153 (1) RATS/CTD154 (1) RATS/CTD156 (1) RATS/CTD157 (1) RATS/CTD160 (1) RATS/CTD163 (1) RATS/CTD164 (1) RATS/CTD166 (1) RATS/CTD167 (1) RATS/CTD169 (1) RATS/CTD170 (1) RATS/CTD173 (1) RATS/CTD175 (1) RATS/CTD177 (1) RATS/CTD180 (1) RATS/CTD182 (1) RATS/CTD184 (1) RATS/CTD186 (1) RATS/CTD189 (1) RATS/CTD191 (1) RATS/CTD193 (1) RATS/CTD195 (1) RATS/CTD198 (1) RATS/CTD200 (1) RATS/CTD202 (1) RATS/CTD204 (1) RATS/CTD206 (1) RATS/CTD208 (1) RATS/CTD210 (1) RATS/CTD214 (1) RATS/CTD217 (1) RATS/CTD219 (1) RATS/CTD221 (1) RATS/CTD223 (1) RATS/CTD225 (1) RATS/CTD227 (1) RATS/CTD230 (1) RATS/CTD232 (1) RATS/CTD234 (1) RATS/CTD237 (1) RATS/CTD239 (1) RATS/CTD241 (1) RATS/CTD243 (1) RATS/CTD245 (1) RATS/CTD247 (1) RATS/CTD249 (1) RATS/CTD251 (1) RATS/CTD254 (1) RATS/CTD256 (1) RATS/CTD258 (1) RATS/CTD260 (1) RATS/CTD262 (1) RATS/CTD265 (1) RATS/CTD267 (1) RATS/CTD269 (1) RATS/CTD271 (1) RATS/CTD273 (1) RATS/CTD275 (1) RATS/CTD277 (1) RATS/CTD281 (1) RATS/CTD283 (1) RATS/CTD285 (1) RATS/CTD287 (1) RATS/CTD289 (1) RATS/CTD291 (1) RATS/CTD293 (1) RATS/CTD295 (1) RATS/CTD297 (1) RATS/CTD301 (1) RATS/CTD305 (1) RATS/CTD307 (1) RATS/CTD309 (1) RATS/CTD311 (1) RATS/CTD313 (1) RATS/CTD315 (1) RATS/CTD317 (1) RATS/CTD319 (1) RATS/CTD321 (1) RATS/CTD323 (1) RATS/CTD325 (1) RATS/CTD327 (1) RATS/CTD329 (1) RATS/CTD331 (1) RATS/CTD335 (1) RATS/CTD337 (1) RATS/CTD341 (1) RATS/CTD343 (1) RATS/CTD345 (1) RATS/CTD347 (1) RATS/CTD351 (1) RATS/CTD353 (1) RATS/CTD355 (1) RATS/CTD357 (1) RATS/CTD361 (1) RATS/CTD363 (1) RATS/CTD365 (1) RATS/CTD373 (1) RATS/CTD375 (1) RATS/CTD377 (1) RATS/CTD379 (1) RATS/CTD381 (1) RATS/CTD383 (1) RATS/CTD385 (1) RATS/CTD387 (1) RATS/CTD389 (1) RATS/CTD395 (1) RATS/CTD397 (1) RATS/CTD399 (1) RATS/CTD401 (1) RATS/CTD403 (1) RATS/CTD405 (1) RATS/CTD407 (1) RATS/CTD409 (1) RATS/CTD411 (1) RATS/CTD415 (1) RATS/CTD417 (1) RATS/CTD419 (1) RATS/CTD423 (1) RATS/CTD425 (1) RATS/CTD427 (1) RATS/CTD429 (1) RATS/CTD43 (1) RATS/CTD431 (1) RATS/CTD433 (1) RATS/CTD437 (1) RATS/CTD439 (1) RATS/CTD443 (1) RATS/CTD445 (1) RATS/CTD461 (1) RATS/CTD463 (1) RATS/CTD465 (1) RATS/CTD467 (1) RATS/CTD469 (1) RATS/CTD471 (1) RATS/CTD473 (1) RATS/CTD475 (1) RATS/CTD477 (1) RATS/CTD479 (1) RATS/CTD481 (1) RATS/CTD483 (1) RATS/CTD485 (1) RATS/CTD487 (1) RATS/CTD489 (1) RATS/CTD49 (1) RATS/CTD491 (1) RATS/CTD493 (1) RATS/CTD495 (1) RATS/CTD497 (1) RATS/CTD499 (1) RATS/CTD501 (1) RATS/CTD503 (1) RATS/CTD505 (1) RATS/CTD507 (1) RATS/CTD509 (1) RATS/CTD51 (1) RATS/CTD511 (1) RATS/CTD513 (1) RATS/CTD515 (1) RATS/CTD517 (1) RATS/CTD519 (1) RATS/CTD521 (1) RATS/CTD523 (1) RATS/CTD525 (1) RATS/CTD527 (1) RATS/CTD529 (1) RATS/CTD53 (1) RATS/CTD531 (1) RATS/CTD534 (1) RATS/CTD536 (1) RATS/CTD538 (1) RATS/CTD540 (1) RATS/CTD542 (1) RATS/CTD545 (1) RATS/CTD547 (1) RATS/CTD549 (1) RATS/CTD55 (1) RATS/CTD551 (1) RATS/CTD553 (1) RATS/CTD555 (1) RATS/CTD557 (1) RATS/CTD559 (1) RATS/CTD561 (1) RATS/CTD563 (1) RATS/CTD565 (1) RATS/CTD567 (1) RATS/CTD569 (1) RATS/CTD571 (1) RATS/CTD573 (1) RATS/CTD575 (1) RATS/CTD577 (1) RATS/CTD579 (1) RATS/CTD58 (1) RATS/CTD581 (1) RATS/CTD583 (1) RATS/CTD585 (1) RATS/CTD587 (1) RATS/CTD589 (1) RATS/CTD591 (1) RATS/CTD593 (1) RATS/CTD595 (1) RATS/CTD597 (1) RATS/CTD599 (1) RATS/CTD60 (1) RATS/CTD601 (1) RATS/CTD603 (1) RATS/CTD605 (1) RATS/CTD607 (1) RATS/CTD609 (1) RATS/CTD611 (1) RATS/CTD613 (1) RATS/CTD615 (1) RATS/CTD617 (1) RATS/CTD619 (1) RATS/CTD62 (1) RATS/CTD621 (1) RATS/CTD623 (1) RATS/CTD625 (1) RATS/CTD627 (1) RATS/CTD629 (1) RATS/CTD631 (1) RATS/CTD633 (1) RATS/CTD635 (1) RATS/CTD637 (1) RATS/CTD639 (1) RATS/CTD64 (1) RATS/CTD654 (1) RATS/CTD66 (1) RATS/CTD669 (1) RATS/CTD678 (1) RATS/CTD68 (1) RATS/CTD687 (1) RATS/CTD695 (1) RATS/CTD70 (1) RATS/CTD705 (1) RATS/CTD72 (1) RATS/CTD722 (1) RATS/CTD724 (1) RATS/CTD727 (1) RATS/CTD729 (1) RATS/CTD731 (1) RATS/CTD733 (1) RATS/CTD735 (1) RATS/CTD737 (1) RATS/CTD739 (1) RATS/CTD74 (1) RATS/CTD741 (1) RATS/CTD743 (1) RATS/CTD745 (1) RATS/CTD747 (1) RATS/CTD749 (1) RATS/CTD751 (1) RATS/CTD753 (1) RATS/CTD755 (1) RATS/CTD757 (1) RATS/CTD759 (1) RATS/CTD761 (1) RATS/CTD763 (1) RATS/CTD765 (1) RATS/CTD767 (1) RATS/CTD77 (1) RATS/CTD771 (1) RATS/CTD773 (1) RATS/CTD775 (1) RATS/CTD777 (1) RATS/CTD779 (1) RATS/CTD781 (1) RATS/CTD783 (1) RATS/CTD785 (1) RATS/CTD787 (1) RATS/CTD789 (1) RATS/CTD795 (1) RATS/CTD797 (1) RATS/CTD799 (1) RATS/CTD80 (1) RATS/CTD801 (1) RATS/CTD803 (1) RATS/CTD805 (1) RATS/CTD807 (1) RATS/CTD809 (1) RATS/CTD811 (1) RATS/CTD813 (1) RATS/CTD817 (1) RATS/CTD819 (1) RATS/CTD82 (1) RATS/CTD821 (1) RATS/CTD823 (1) RATS/CTD825 (1) RATS/CTD827 (1) RATS/CTD829 (1) RATS/CTD831 (1) RATS/CTD833 (1) RATS/CTD837 (1) RATS/CTD839 (1) RATS/CTD84 (1) RATS/CTD841 (1) RATS/CTD843 (1) RATS/CTD845 (1) RATS/CTD847 (1) RATS/CTD849 (1) RATS/CTD851 (1) RATS/CTD853 (1) RATS/CTD855 (1) RATS/CTD857 (1) RATS/CTD859 (1) RATS/CTD861 (1) RATS/CTD863 (1) RATS/CTD865 (1) RATS/CTD867 (1) RATS/CTD869 (1) RATS/CTD87 (1) RATS/CTD871 (1) RATS/CTD873 (1) RATS/CTD879 (1) RATS/CTD881 (1) RATS/CTD883 (1) RATS/CTD885 (1) RATS/CTD887 (1) RATS/CTD889 (1) RATS/CTD89 (1) RATS/CTD891 (1) RATS/CTD893 (1) RATS/CTD895 (1) RATS/CTD897 (1) RATS/CTD899 (1) RATS/CTD901 (1) RATS/CTD903 (1) RATS/CTD905 (1) RATS/CTD907 (1) RATS/CTD909 (1) RATS/CTD91 (1) RATS/CTD913 (1) RATS/CTD915 (1) RATS/CTD917 (1) RATS/CTD919 (1) RATS/CTD921 (1) RATS/CTD923 (1) RATS/CTD925 (1) RATS/CTD927 (1) RATS/CTD929 (1) RATS/CTD93 (1) RATS/CTD931 (1) RATS/CTD933 (1) RATS/CTD935 (1) RATS/CTD937 (1) RATS/CTD939 (1) RATS/CTD941 (1) RATS/CTD943 (1) RATS/CTD945 (1) RATS/CTD947 (1) RATS/CTD949 (1) RATS/CTD951 (1) RATS/CTD953 (1) RATS/CTD955 (1) RATS/CTD957 (1) RATS/CTD959 (1) RATS/CTD96 (1) RATS/CTD961 (1) RATS/CTD963 (1) RATS/CTD965 (1) RATS/CTD967 (1) RATS/CTD969 (1) RATS/CTD971 (1) RATS/CTD973 (1) RATS/CTD975 (1) RATS/CTD977 (1) RATS/CTD979 (1) RATS/CTD98 (1) RATS/CTD981 (1) RATS/CTD983 (1) RATS/CTD985 (1) RATS/CTD987 (1) RATS/CTD989 (1) RATS/CTD991 (1)


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