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Metadata Report for BODC Series Reference Number 1743816


Metadata Summary

Data Description

Data Category Bathythermograph -expendable
Instrument Type
NameCategories
Lockheed Martin Sippican T-5 XBT probe  bathythermographs; water temperature sensor; Expendable bathythermographs
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Dr Jon Watkins
Originating Organization British Antarctic Survey
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) -
 

Data Identifiers

Originator's Identifier T5_00018
BODC Series Reference 1743816
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2009-12-23 07:41
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 0.7 metres
 

Spatial Co-ordinates

Latitude 53.86789 S ( 53° 52.1' S )
Longitude 37.72817 W ( 37° 43.7' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor or Sampling Depth 2.7 m
Maximum Sensor or Sampling Depth 1830.5 m
Minimum Sensor or Sampling Height -
Maximum Sensor or Sampling Height -
Sea Floor Depth -
Sea Floor Depth Source -
Sensor or Sampling Distribution Variable common depth - All sensors are grouped effectively at the same depth, but this depth varies significantly during the series
Sensor or Sampling Depth Datum Unspecified -
Sea Floor Depth Datum -
 

Parameters

BODC CODERankUnitsTitle
ACYCAA011DimensionlessSequence number
DEPHCV011MetresDepth (spatial coordinate) relative to water surface in the water body by computation from probe free-fall time using unspecified algorithm
SVELCV011Metres per secondSound velocity in the water body by computation from temperature and salinity by unspecified algorithm
TEMPET011Degrees CelsiusTemperature of the water body by expendable bathythermograph (XBT)

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 Quality Report

During visual screening procedures M flags were applied to suspect values identified on the following series:

Series Reference Comments
1743632 From cycle 2238 to end of cast
1743644 From cycle 2062 to end of cast
1743681 From cycle 1264 to end of cast
1743693 From cycle 526 to end of cast
1743700 From cycle 623 to end of cast
1743761 From cycle 733 to end of cast
1743797 From cycle 802 to end of cast
1743804 From cycle 336 to end of cast
1743816 From cycle 788 to end of cast
1743828 From cycle 329 to end of cast
1743841 From cycle 176 to end of cast
1743853 From cycle 1531 to end of cast
1743921 From cycle 1257 to end of cast
1743933 From cycle 305 to end of cast
1743957 Flagged cycles 44-152, 187-401 and from 641 to end of cast
1743969 From cycle 2092 to end of cast
1743970 Flagged the whole cast
1743994 Flagged the whole cast
1744008 Flagged the whole cast
1744021 Flagged the whole cast
1744033 Flagged the whole cast
1744045 From cycle 371 to end of cast
1744057 From cycle 333 to end of cast
1744069 From cycle 1803 to end of cast

Possible causes for the anomalous data can be due to wire snapping or probe hitting the sea floor. The originator reported that 5 XBT's collected data despite not being deployed, this was due to a malfunction in the XBT gun.


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

Instrument description

Lockheed Martin Sippican T-5 XBT Probe

The Expendable Bathythermograph system uses a sea water ground. As soon as an electrode within the nose of the expendable probe makes contact with the water, the circuit is complete and temperature or sound velocity data can be telemetered to the ship-board data processing equipment. The T-5 XBT Probe can be used within a maximum depth of 1830 m, with a rated ship speed of 6 knots and has a vertical resolution of 65 cm.

Manufacturer specifications can be found here

Originator's processing document for JR20091212 (JR228) XBT data

Sampling strategy

39 Sippican T5 Expendable Bathythermographs probes (XBT) were launched whilst the ship was sailing at 6 knots. The data were transferred to a PC via a USB interface that provided the communication with the XBT launcher.

Data Processing

When data were exported, a noise reduction procedure was applied. The noise threshold was of 3.0. Sound Velocity was calculated by assuming the following salinities:

Series Reference Salinity
1743632 33.95
1743644 34
1743656 33.88
1743668 33.86
1743681 33.9
1743693 33.84
1743700 33.85
1743712 33.85
1743724 33.85
1743736 33.96
1743748 33.97
1743761 33.97
1743773 34
1743785 33.8
1743797 33.84
1743804 33.83
1743816 33.82
1743828 33.82
1743841 33.8
1743853 33.84
1743865 33.96
1743877 33.96
1743889 33.87
1743890 33.95
1743908 33.85
1743921 33.77
1743933 33.78
1743945 33.83
1743957 33.83
1743969 33.8
1743970 33.78
1743982 33.78
1743994 33.8
1744008 33.8
1744021 33.8
1744033 33.8
1744045 33.8
1744057 33.8
1744069 31.9

Processing by BODC of RRS James Clark Ross JR20091212 (JR228) XBT data

The files were sent to BODC in .EDF format, which can be opened with a text editor. No processing was carried out at BODC.

The files were converted to BODC internal format (QXF) using BODC established procedures. There was no need to apply unit conversions as the originator's units were equivalent to the units stored on BODC's vocabulary dictionary.

The following table shows how the variables within the originator's files were mapped to appropriate BODC parameter codes:

Originator's Parameter Name Units Description BODC Parameter Code Units
Depth m Depth below surface of the water body by computation from probe free-fall time using unspecified algorithm DEPHCV01 m
Temperature °C Temperature of the water body by expendable bathythermograph (XBT) TEMPET01 °C
Sound Velocity m s-1 Sound velocity in the water body by computation from temperature and salinity by unspecified algorithm SVELCV01 m s-1

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


Project Information


No Project Information held for the Series

Data Activity or Cruise Information

Cruise

Cruise Name JR20091211 (JR228)
Departure Date 2009-12-11
Arrival Date 2009-12-30
Principal Scientist(s)Jonathan L Watkins (British Antarctic Survey)
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