Metadata Report for BODC Series Reference Number 751867


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 Garaint Tarling
Originating Organization British Antarctic Survey
Processing Status banked
Project(s) DISCOVERY 2010
 

Data Identifiers

Originator's Identifier T5_00056
BODC Series Reference 751867
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2008-02-07 02:13
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 0.7 metres
 

Spatial Co-ordinates

Latitude 50.52950 S ( 50° 31.8' S )
Longitude 34.05683 W ( 34° 3.4' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth 2.0 m
Maximum Sensor Depth 411.7 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

Data Quality Report

Cycles 257 to 611 were flagged as suspect.


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 JR20071227 (JR177, JR205, JR207) XBT data

The data arrived at BODC in 56 ASCII format files representing the casts taken during JR20071227. These were reformatted to the internal QXF format using established BODc procedures. The following table shows how the variables within the ASCII files were mapped to appropriate BODC parameter codes:

Originator's Variable 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
Sound Velocity m s -1 Sound velocity in the water body by computation from temperature and salinity by unspecified SVELCV01 m s -1
Temperature °C Temperature of the water body by expendable bathythermograph (XBT) TEMPET01 °C

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.

Instrument Description

XBT Unit and Auxiliary Sensors

Probe Type T-5
Terminal Depth 1830 m
Depth Equation Standard
Depth Coeff. 1 0.0
Depth Coeff. 2 6.828
Depth Coeff. 3 -0.00182
Depth Coeff. 4 0.0
Pressure Pt Correction 100.0%

Project Information

DISCOVERY 2010

DISCOVERY 2010 will investigate and describe the response of an ocean ecosystem to climate variability, climate change and commercial exploitation. The programme builds on past studies by BAS on the detailed nature of the South Georgia marine ecosystem and its links with the large-scale physical and biological behaviour of the Southern Ocean.

The aim is to identify, quantify and model key interactions and processes on scales that range from microscopic life forms to higher predators (penguins, albatrosses, seals and whales), and from the local to the circumpolar.

Objectives

Assess the links between the status of local marine food webs and variability and change in the Southern Ocean. Develop a linked set of ecosystem models applying relevant marine physics and biology over scales from the local to that of the entire Southern Ocean.

Relevance to Global Science

Ocean ecosystems play a crucial role in maintaining biodiversity, in depositing carbon into the deep ocean, and as a source of protein for humans. However, fishing and climate change are having significant and often detrimental effects. To predict the future state of ocean ecosystems we must develop computer models capable of simulating biological and physical processes on a range of scales from the local to an entire ocean. Developing such predictive models is crucial to the sustainable management of world fisheries and requires integrated analyses of the way whole ecosystems work. DISCOVERY 2010 aims to take this work forward and at the same time help manage the South Georgia and South Sandwich Islands maritime zone. We will do this through providing information on the state of the ecosystem to the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), the international body that manages sustainable fishing in the Southern Ocean.

Delivering the Results

DISCOVERY 2010 will undertake an integrated programme of shipboard and land-based field studies of the marine food web, combined with modelling. We will pay particular attention to critical phases in the life cycles of key species, and to examining interactive effects in food webs. Interacting biological and physical processes will be modelled across a range of spatial scales to significantly improve our representation of the ocean ecosystem, upon which sustainable management and the prediction of future climate change can be based. DISCOVERY 2010 will link to BIOFLAME, ACES, and COMPLEXITY, two international programmes, and to a collaborative programme with the University of East Anglia on the role of the Southern Ocean in the global carbon cycle.

Component Projects


Data Activity or Cruise Information

Cruise

Cruise Name JR20071227 ( JR177, JR205, JR207)
Departure Date 2007-12-31
Arrival Date 2008-02-16
Principal Scientist(s)Geraint Tarling (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