Metadata Report for BODC Series Reference Number 1743355


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 Mr Hugh Venables
Originating Organization British Antarctic Survey
Processing Status banked
Project(s) DISCOVERY 2010
 

Data Identifiers

Originator's Identifier JR161XBT16
BODC Series Reference 1743355
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2006-10-31 09:32
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 1.0 decibars
 

Spatial Co-ordinates

Latitude 58.92132 S ( 58° 55.3' S )
Longitude 49.87822 W ( 49° 52.7' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth 2.7 m
Maximum Sensor Depth 1337.2 m
Minimum Sensor Height 2483.3 m
Maximum Sensor Height 3817.8 m
Sea Floor Depth 3820.5 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 Chart reference - Depth extracted from available chart
 

Parameters

BODC CODE Rank Units Short Title Title
ACYCAA01 1 Dimensionless Record_No Sequence number
PRESCX01 1 Decibars Press Pressure (spatial co-ordinate) exerted by the water body by computation of depth using unspecified drop rate algorithm converted to pressure using UNESCO 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 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

RRS James Clark Ross cruise JR20061024 (JR161) XBT data

Cruise details

Dates (UT) 2006-10-24 to 2006-12-03
Principal Scientific Officer Rachael Shreeve, British Antarctic Survey, Cambridge

Content of data series

Parameter Units Parameter code
Pressure dbar PRESCX01
Temperature °C TEMPET01

Instrument Descriptions

Sippican T5 probes were deployed during the cruise. The launcher was clamped to the rear of the aft deck on board the James Clark Ross.

Originator's Data Processing

Sampling Strategy

A total of 32 XBTs were launched whilst the ship was sailing. The ship decreased its speed to 8 knots for deploying most probes and data were logged by a Viglen IBM-type 486 PC running the Sippican WinMk12 software. Data were written directly to the Unix system.

During part of the cruise, the magnetometer was also deployed, which limited the XBTs depth to about 600 m. For some deployments the ship's speed was kept at about 10 knots, which resulted in data being collected to only a depth of 1000 m. Whenever excessive spiking or clearly unrealistic values were logged,, the drop was aborted and a new probe was launched.

Data Processing

Matlab scripts were used to process the XBT data, the procedures involved reading the ascii files converting them to .mat format.

BODC Processing

Data Processing

32 files were processed at the British Antarctic Survey and were sent to BODC in .mat format.

Reformatting

The data were converted to BODC internal format using BODC's established procedures. 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
pres - Pressure (spatial co-ordinate) exerted by the water body by computation of depth using unspecified drop rate algorithm converted to pressure using UNESCO algorithm PRESCX01 dbar
temp - Temperature of the water body by expendable bathythermograph (XBT) TEMPET01 °C

Screening

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

Banking

Once quality control screening was complete, all CTD downcasts were loaded into BODC's shelf sea database under the Oracle Relational Database Management System.


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 JR20061024 (JR156, JR161)
Departure Date 2006-10-24
Arrival Date 2006-12-03
Principal Scientist(s)Rachael Shreeve (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