Metadata Report for BODC Series Reference Number 912975


Metadata Summary

Data Description

Data Category Currents -subsurface Eulerian
Instrument Type
NameCategories
Teledyne RDI 300kHz Workhorse Monitor direct-reading ADCP  current profilers
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Mr David Hamersley
Originating Organization National Oceanography Centre, Southampton
Processing Status banked
Project(s) Oceans 2025
Oceans 2025 Theme 1
Oceans 2025 Theme 1 WP1.3
 

Data Identifiers

Originator's Identifier PRO_DATA_J001_02_UPCAST
BODC Series Reference 912975
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2009-02-05 14:41
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 20.0 metres
 

Spatial Co-ordinates

Latitude 57.13000 S ( 57° 7.8' S )
Longitude 68.25000 W ( 68° 15.0' W )
Positional Uncertainty Unspecified
Minimum Sensor Depth 20.0 m
Maximum Sensor Depth 4380.0 m
Minimum Sensor Height 12.0 m
Maximum Sensor Height 4372.0 m
Sea Floor Depth 4392.0 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 Unspecified -
Sea Floor Depth Datum Approximate - Depth is only approximate
 

Parameters

BODC CODE Rank Units Short Title Title
ACYCAA01 1 Dimensionless Record_No Sequence number
ADEPZZ01 1 Metres DepBelowSurf Depth below surface of the water body
LCEWLW01 1 Centimetres per second CurrVelE_ADCP Eastward current velocity (Eulerian) in the water body by lowered acoustic doppler current profiler (ADCP)
LCNSLW01 1 Centimetres per second CurrVelN_ADCP Northward current velocity (Eulerian) in the water body by lowered acoustic doppler current profiler (ADCP)
LRZALW01 1 Centimetres per second UpVelLADCP Upward current velocity in the water body by lowered acoustic doppler current profiler (ADCP)
NLADCPBN 1 Dimensionless Num_LADCP_bin Number (per bin) of measurements by lowered acoustic doppler current profiler (ADCP)
SDEWLW01 1 Centimetres per second Std_dev_EW_LADCP Eastward current velocity standard deviation (Eulerian) in the water body by lowered acoustic doppler current profiler (ADCP)
SDNSLW01 1 Centimetres per second Std_dev_NS_LADCP Northward current velocity standard deviation (Eulerian) in the water body by lowered acoustic doppler current profiler (ADCP)
SDZALW01 1 Centimetres per second UpVelStdDevLADCP Upward current velocity standard deviation in the water body by lowered acoustic doppler current profiler (ADCP)
 

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

No Problem Report Found in the Database


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

Teledyne RDI's Workhorse Monitor ADCP

The Workhorse Monitor acoustic doppler current profler (Teledyne RD Instruments) is a long-range and long-term self contained ADCP. It has a patented four beam signal (300, 600 or 1200 kHz) and a standard depth rating of 200m or 600m. It operates effectively between temperatures of -5°C and 45°C and has a velocity accuracy of ±1% ±5mm/s.

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)

BODC Processing

The data arrived at BODC in 81 Matlab (.MAT) format files. These represented all of the available measurements taken during the cruise that were processed using the shear method implemented in University of Hawaii software. The downcast and upcast data were reformatted into separate internal QXF format files using BODC transfer function 438. The following table shows how the upcast variables within the .MAT files were mapped to appropriate BODC parameter codes:

Originator's Variables Units Description BODC Parameter Code Units Comment
d_samp metres Depth below sea surface (ADCP bin) DBINAA01 metres  
pxy decimal degrees latitude and longitude position at start - - Not transferred
sm_dn_i - Flags indicating whether bin contains real or fill value (downcast) - - Not converted
sm_mn_i - Flags indicating whether bin contains real or fill value (mean) - - Not converted - mean data are not transferred into QXF
sm_up_i - Flags indicating whether bin contains real or fill value (upcast) - - Converted to BODC QC flags
sn_dn_i None Number (per bin) of measurements by lowered acoustic doppler current profiler (ADCP) (downcast) - - Not transferred
sn_mn_i None Number (per bin) of measurements by lowered acoustic doppler current profiler (ADCP) (mean) - - Not transferred - mean data are not transferred into QXF
sn_up_i None Number (per bin) of measurements by lowered acoustic doppler current profiler (ADCP) (upcast) NLADCPBN None  
su_dn_i m s -1 Eastward current velocity (Eulerian) in the water column (downcast) - - Not transferred
su_mn_i m s -1 Eastward current velocity (Eulerian) in the water column (mean) - - Not transferred - can be derived from upcast and downcast velocities
su_up_i m s -1 Eastward current velocity (Eulerian) in the water column (upcast) LCEWLW01 cm s -1 Velocity * 100
sv_dn_i m s -1 Northward current velocity (Eulerian) in the water column (downcast) - - Not transferred
sv_mn_i m s -1 Northward current velocity (Eulerian) in the water column (mean) - - Not transferred - can be derived from upcast and downcast velocities
sv_up_i m s -1 Northward current velocity (Eulerian) in the water column (upcast) LCNSLW01 cm s -1 Velocity * 100
sw_dn_i m s -1 Upward current velocity in the water column (downcast) - - Not transferred
sw_mn_i m s -1 Upward current velocity in the water column (mean) - - Not transferred - can be derived from upcast and downcast velocities
sw_up_i m s -1 Upward current velocity in the water column (upcast) LRZALW01 cm s -1 Velocity * 100
sv_var_dn_i m s -1 Variance of shear in the northward velocity component (downcast) - - Not transferred
sv_var_mn_i m s -1 Variance of shear in the northward velocity component (mean) - - Not transferred - can be derived from upcast and downcast velocities
sv_var_up_i m s -1 Variance of shear in the northward velocity component (upcast) SDNSLW01 cm s -1 (variance 0.5 ) * 100
sw_var_dn_i m s -1 Variance of shear in the upward velocity component (downcast) - - Not transferred
sw_var_mn_i m s -1 Variance of shear in the upward velocity component (mean) - - Not transferred - can be derived from upcast and downcast velocities
sw_var_up_i m s -1 Variance of shear in the upward velocity component (upcast) SDZALW01 cm s -1 (variance 0.5 ) * 100
su_var_dn_i m s -1 Variance of shear in the eastward velocity component (downcast) - - Not transferred
su_var_mn_i m s -1 Variance of shear in the eastward velocity component (mean) - - Not transferred - can be derived from upcast and downcast velocities
su_var_up_i m s -1 Variance of shear in the eastward velocity component (upcast) SDEWLW01 cm s -1 (variance 0.5 ) * 100
txy_start_end decimal Day, latitude and longitude at start and end of profile - - Not transferred into QXF

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

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.

In total 84 CTD (conductivity-temperature-depth) stations were occupied. A 24-bottle rosette was used to take water samples at these CTD stations. Also mounted on the frame was a LADCP (lowered acoustic doppler current profiler), fluorometer, transmissometer, and a dissolved oxygen sensor. Of these casts, only 81 yielded LADCP measurements. This was due to an incident with the winch during station 12 which caused the total loss of the CTD package (including LADCP). Data was not collected during station 13 as this was only a test station. Station 50 did not yield any LADCP data because the deploy command was not sent. Stations 35 and 36 were repeats of station 34.

Data Processing

Data collected from the instrument was downloaded after each cast by the technician on watch. Subsequently, data were processed using two methods; the shear method implemented in University of Hawaii software and the least squares method implemented in LDEO software version 7. Further information about processing methods can be found in the report (from p68) for cruise RRS Charles Darwin 139 (CD139). Additional information can also be found in the LADCP report from cruise JC031.


Project Information

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


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