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Metadata Report for BODC Series Reference Number 1813521


Metadata Summary

Data Description

Data Category Currents -subsurface Eulerian
Instrument Type
NameCategories
Teledyne RDI Ocean Surveyor 75 kHz vessel-mounted ADCP  current profilers
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Dr Peggy Courtois
Originating Organization University of Southampton School of Ocean and Earth Science
Processing Status banked
Online delivery of data Download not available
Project(s) DIMES
 

Data Identifiers

Originator's Identifier OS75_JR276NNX_01
BODC Series Reference 1813521
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2011-04-11 15:44
End Time (yyyy-mm-dd hh:mm) 2011-04-26 10:57
Nominal Cycle Interval -
 

Spatial Co-ordinates

Start Latitude 56.49991 S ( 56° 30.0' S )
End Latitude 56.49991 S ( 56° 30.0' S )
Start Longitude 77.99994 W ( 77° 60.0' W )
End Longitude 77.99996 W ( 77° 60.0' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor or Sampling Depth 30.24 m
Maximum Sensor or Sampling Depth 814.29 m
Minimum Sensor or Sampling Height -
Maximum Sensor or Sampling Height -
Sea Floor Depth -
Sea Floor Depth Source -
Sensor or Sampling Distribution Sensor fixed with measurements made at multiple depths within a fixed range (e.g. ADCP) - The sensor is at a fixed depth, but measurements are made remotely from the sensor over a range of depths (e.g. ADCP measurements)
Sensor or Sampling Depth Datum Approximate - Depth is only approximate
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODERankUnitsTitle
BINNUMBR0DimensionlessBin number
AADYAA011DaysDate (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ011DaysTime (time between 00:00 UT and timestamp)
ACYCAA011DimensionlessSequence number
ALATGP011DegreesLatitude north relative to WGS84 by unspecified GPS system
ALONGP011DegreesLongitude east relative to WGS84 by unspecified GPS system
APEWGP011Centimetres per secondEastward velocity of measurement platform relative to ground surface by unspecified GPS system
APNSGP011Centimetres per secondNorthward velocity of measurement platform relative to ground surface by unspecified GPS system
DBINAA012MetresDepth (spatial coordinate) of ADCP bin relative to water surface {bin depth} in the water body
LCEWAS012Centimetres per secondEastward velocity of water current (Eulerian measurement) in the water body by shipborne acoustic doppler current profiler (ADCP)
LCNSAS012Centimetres per secondNorthward velocity of water current (Eulerian measurement) in the water body by shipborne 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

These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.

If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:

"Contains public sector information licensed under the Open Government Licence v1.0."


Narrative Documents

RD Instruments- Ocean Surveyor 75kHz Vessel mounted ADCP.

Long-Range Mode
Vertical Resolution Cell Size3 Max. Range (m)1 Precision (cm/s)2
8m 520 - 650 30
16m 560 - 700 17
High-Precision Mode
Vertical Resolution Cell Size3 Max. Range (m)1 Precision (cm/s)2
8m 310 - 430 12
16m 350 - 450 9

1 Ranges at 1 to 5 knots ship speed are typical and vary with situation.
2 Single-ping standard deviation.
3 User's choice of depth cell size is not limited to the typical values specified.

Profile Parameters

  • Velocity long-term accuracy (typical): ±1.0%, ±0.5cm/s
  • Velocity range: -5 to 9m/s
  • # of depth cells: 1 - 128
  • Max ping rate: 0.7

Bottom Track

Maximum altitude (precision <2cm/s): 950m

Echo Intensity Profile

Dynamic range: 80dB
Precision: ±1.5dB

Transducer and Hardware

Beam angle: 30°
Configuration: 4-beam phased array
Communications: RS-232 or RS-422 hex-ASCII or binary output at 1200 - 115,200 baud
Output power: 1000W

Standard Sensors

Temperature (mounted on transducer)

  • Range: -5° to 45°C
  • Precision: ±0.1°C
  • Resolution: 0.03°

Environmental

Operating temperature: -5° to 40°C (-5° to 45°C)*
Storage temperature: -30° to 50°C (-30° to 60°C)*

*later instruments have greater range.

Web Page

Further details can be found on the manufacturer's website or in the specification sheet

WOCE SR1b Drake Passage cruise JR276 75 kHz RD Instruments Ocean Surveyor (OS75) ADCP data processing

The following was taken from the JR20110409 (JR276, UKD-2.5) cruise report. For more detailed information please refer to the cruise report.

Data were acquired from the OS75 using Version 1.42 of the RDI VmDas software.

ADCP setup

Variable Setting
Number of Bins 50
Bin size 16m
Blanking distance 8m
Transducer depth 6.3m
Processing mode Two processing modes during JR276: narrowband with bottom-tracking on and narrowband with bottom-tracking off.
Maximum range 800m

Post-processing

The final processing of data was done using the Hawaii CODAS System.. The processing route can be summarised as copying the raw files, converting them into a working format, merging navigation data, deriving velocities, quality control, and conversion of data to matlab and netcdf files.

Calibration

Calibrations derived from the CODAS processing.

The water track mode amplitude average was 1.0179 and the average phase was -1.1023. The Bottom track mode amplitude average was 1.0116 and the average phase was -1.0564.

Processing by BODC of RRS James Clark Ross Vessel Mounted ADCP data: JR20110409 (JR276, UKD-2.5)

The data arrived at BODC in one MStar file representing the data collected from the vessel mounted ADCP during cruise JR20110409 (JR276, UKD-2.5). The data were reformatted to BODC's internal NetCDF format. The following table shows the mapping of variables within the MStar file to appropriate BODC parameter codes:

Originator's Variable Originator's Units BODC Parameter Code BODC Units Comment
uabs cm/s LCEWAS01 cm/s -
vabs cm/s LCNSAS01 cm/s -
uship m/s APEWGP01 cm/s Conversion *100 applied
vship m/s APNSGP01 cm/s Conversion *100 applied
speed cm/s - - Not transferred as direction is not included
shipspd m/s - - Not transferred as direction is not included
depth metres DBINAA01 metres -
lat degrees ALATGP01 degrees -
lon degrees ALONGP01 degrees Conversion from -180 to 180 applied

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.


Project Information

Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) project document

DIMES is a US/UK field program aimed at measuring diapycnal and isopycnal mixing in the Southern Ocean, along the tilting isopycnals of the Antarctic Circumpolar Current.

The Meridional Overturning Circulation (MOC) of the ocean is a critical regulator of the Earth's climate processes. Climate models are highly sensitive to the representation of mixing processes in the southern limb of the MOC, within the Southern Ocean, although the lack of extensive in situ observations of Southern Ocean mixing processes has made evaluation of mixing somewhat difficult. Theories and models of the Southern Ocean circulation have been built on the premise of adiabatic flow in the ocean interior, with diabatic processes confined to the upper-ocean mixed layer. Interior diapycnal mixing has often been assumed to be small, but a few recent studies have suggested that diapycnal mixing might be large in some locations, particularly over rough bathymetry. Depending on its extent, this interior diapycnal mixing could significantly affect the overall energetics and property balances for the Southern Ocean and in turn for the global ocean. The goals of DIMES are to obtain measurements that will help us quantify both along-isopycnal eddy-driven mixing and cross-isopycnal interior mixing.

DIMES includes tracer release, isopycnal following RAFOS floats, microstructure measurements, shearmeter floats, EM-APEX floats, a mooring array in Drake Passage, hydrographic observations, inverse modeling, and analysis of altimetry and numerical model output.

DIMES is sponsored by the National Science Foundation (U.S.), Natural Environment Research Council (U.K) and British Antarctic Survey (U.K.)

For more information please see the official project website at DIMES


Data Activity or Cruise Information

Cruise

Cruise Name JR20110409 (JR276, UKD-2.5)
Departure Date 2011-04-09
Arrival Date 2011-04-26
Principal Scientist(s)Andrew J Watson (University of East Anglia School of Environmental Sciences)
Ship RRS James Clark Ross

Complete Cruise Metadata Report is available here


Fixed Station Information


No Fixed Station Information held for the Series


BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Flag Description
Blank Unqualified
< Below detection limit
> In excess of quoted value
A Taxonomic flag for affinis (aff.)
B Beginning of CTD Down/Up Cast
C Taxonomic flag for confer (cf.)
D Thermometric depth
E End of CTD Down/Up Cast
G Non-taxonomic biological characteristic uncertainty
H Extrapolated value
I Taxonomic flag for single species (sp.)
K Improbable value - unknown quality control source
L Improbable value - originator's quality control
M Improbable value - BODC quality control
N Null value
O Improbable value - user quality control
P Trace/calm
Q Indeterminate
R Replacement value
S Estimated value
T Interpolated value
U Uncalibrated
W Control value
X Excessive difference

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Flag Description
0 no quality control
1 good value
2 probably good value
3 probably bad value
4 bad value
5 changed value
6 value below detection
7 value in excess
8 interpolated value
9 missing value
A value phenomenon uncertain
B nominal value
Q value below limit of quantification