Metadata Report for BODC Series Reference Number 1173737


Metadata Summary

Data Description

Data Category Bathythermograph -expendable
Instrument Type
NameCategories
Lockheed Martin Sippican T-5 XBT probe  bathythermographs; water temperature sensor
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Dr Robert Larter
Originating Organization British Antarctic Survey
Processing Status banked
Project(s) GRADES
 

Data Identifiers

Originator's Identifier T5_00001
BODC Series Reference 1173737
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2008-03-06 03:04
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 1.0 metres
 

Spatial Co-ordinates

Latitude 74.37179 S ( 74° 22.3' S )
Longitude 104.78492 W ( 104° 47.1' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth 2.7 m
Maximum Sensor Depth 1830.5 m
Minimum Sensor Height -
Maximum Sensor Height -
Sea Floor Depth -
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 Instantaneous - Depth measured below water line or instantaneous water body surface
Sea Floor Depth Datum -
 

Parameters

BODC CODE Rank Units Short Title Title
ACYCAA01 1 Dimensionless Record_No Sequence number
DEPHCV01 1 Metres Depth Depth below surface of the water body by computation from probe free-fall time using unspecified algorithm
SVELCV01 1 Metres per second Cmpval Sound velocity in the water body by computation from temperature and salinity by unspecified algorithm
TEMPET01 1 Degrees Celsius XBTTmp Temperature 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

Quality report for James Clark Ross cruise JR20080221 (JR179) XBT data

All casts were screened and M flags applied to cycles where suspect data were identified. The following series/cycles were flagged:

Series reference Cycles Comments
46400 2202-2903 Constant/suspect values
46700 1433-2903 Constant/suspect values

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

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

BODC processing document for XBT data

BODC Processing

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

Reformatted XBT data were visualised using the in-house graphical editor EDSERPLO. Quality control flags were applied to data as necessary.

Originator's processing document for JR20080221 (JR179) XBT data

A total of four expendable bathymetry thermographs (XBT) were launched, at pre-defined positions, during cruise JR20080221 (JR179) whilst the ship was sailing. The data were transferred to a PC via a USB interface that provided the communication with the XBT launcher.

The data were obtained with T5 Sippican probes and were not processed or calibrated by the originator.


Project Information

Glacial Retreat in Antarctica and Deglaciation of the Earth System (GRADES)

Introduction

GRADES was designed to investigate the state and stability of the Antarctic ice sheet, and its results will contribute to a better prediction of how the WAIS contributes to sea level rise.

Throughout the project ice-sheet models will be developed and tested using newly acquired ice-sheets histories. These models will use satellite data, reconstruct ions of past states of the ice sheet and new data assimilation techniques.

This project has three components:

GRADES has links to other BAS programs like GEACEP, CACHE, ACES and COMPLEXITY.

Objectives:

Data Availability

The data produced during this project are available to the academic community.

Acronyms used in the text:


Data Activity or Cruise Information

Cruise

Cruise Name JR20080221 (JR179)
Departure Date 2008-02-21
Arrival Date 2008-04-11
Principal Scientist(s)Peter Enderlein (British Antarctic Survey), Robert D Larter (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