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Metadata Report for BODC Series Reference Number 1806978


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 Mr Hugh Venables
Originating Organization British Antarctic Survey
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) DISCOVERY 2010
 

Data Identifiers

Originator's Identifier JR200XBT2
BODC Series Reference 1806978
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2009-03-29 13:40
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 0.7 decibars
 

Spatial Co-ordinates

Latitude 56.77933 S ( 56° 46.8' S )
Longitude 42.22033 W ( 42° 13.2' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor or Sampling Depth 3.4 m
Maximum Sensor or Sampling Depth 1386.3 m
Minimum Sensor or Sampling Height 2599.2 m
Maximum Sensor or Sampling Height 3982.1 m
Sea Floor Depth 3985.5 m
Sea Floor Depth Source GEBCO1401
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 Approximate - Depth is only approximate
Sea Floor Depth Datum Chart reference - Depth extracted from available chart
 

Parameters

BODC CODERankUnitsTitle
ACYCAA011DimensionlessSequence number
PRESCX011DecibarsPressure (spatial coordinate) exerted by the water body by computation of depth using unspecified drop rate algorithm converted to pressure using UNESCO algorithm
SVELVP011Metres per secondSound velocity in the water body by sound velocity profiler
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

RRS James Clark Ross cruise JR20090310 XBT Data Quality Report

M flags were applied to all cycles where the probe's wire length (1380 m) was exceeded as data were considered anomalous. Please use the flagged data series below with caution.

  • Series 1806978- Flagged from cycle 2151 to the end of the profile
  • Series 1806991- Flagged from cycle 2151 to the end of the profile
  • Series 1807005- Flagged from cycle 2151 to the end of the profile
  • Series 1807017- Flagged from cycle 2152 to the end of the profile
  • Series 1807029- Flagged from cycle 2151 to the end of the profile
  • Series 1807030- Flagged from cycle 2061 to the end of the profile
  • Series 1807042- Flagged from cycle 2152 to the end of the profile
  • Series 1807054- Flagged from cycle 2152 to the end of the profile
  • Series 1807066- Flagged from cycle 2152 to the end of the profile
  • Series 1807078- Flagged from cycle 2152 to the end of the profile
  • Series 1807091- Flagged from cycle 2153 to the end of the profile
  • Series 1807109- Flagged from cycle 1882 to the end of the profile
  • Series 1807110- Flagged from cycle 1876 to the end of the profile
  • Series 1807122- Flagged from cycle 1893 to the end of the profile
  • Series 1807134- Flagged from cycle 2003 to the end of the profile
  • Series 1807146- Flagged from cycle 1988 to the end of the profile
  • Series 1807158- Flagged from cycle 1945 to the end of the profile
  • Series 1807171- Flagged from cycle 1944 to the end of the profile
  • Series 1807183- Flagged from cycle 1918 to the end of the profile
  • Series 1807195- Flagged from cycle 2072 to the end of the profile
  • Series 1807202- Flagged from cycle 1907 to the end of the profile
  • Series 1807214- Flagged from cycle 1973 to the end of the profile

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 JR20090310 XBT data BODC processing

Data Processing

From the 23 deployments, only 22 files were processed at the British Antarctic Survey and were sent to BODC in .mat format as one deployment did not produce a valid file

Reformatting

The data were converted to BODC internal format (QXF) using 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 BODC Parameter Code Units
pres dbar PRESCX01 m
temp °C TEMPET01 °C
soundvel m s-1 SVELVP01 m s-1

Screening was performed on all files and M flags applied to data that was considered anomalous.

RRS James Clark Ross cruise JR20090310 XBT data originator's processing

Originator's Sampling Protocol

Sampling Strategy

A total of 23 XBTs were launched during JR20090310 whilst the ship was sailing to an beyond the Polar Front. Sippican T5 probes were used and launched using a launcher clamped to the rear of the aft deck. The ship's speed was not decreased for deploying probes in order to save time and this led to them not reaching full depth, but resolving 1400m (when launched at 10 knots) and 1200m when launched at 11knots).

Data were logged by a Viglen IBM-type 486 PC running the Sippican WinMk12 software and then written directly to the Unix system.

Data Processing

Matlab scripts were used to process the XBT data, the procedures involved reading the ascii files and using an interactive editor program to remove data at the end of the cast and that was considered to be bad.


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

  • DISCOVERY-OEM: Ocean Ecosystems and Management
  • DISCOVERY-FOOD-WEBS: Scotia Sea FOOD-WEBS
  • DISCOVERY-FLEXICON: FLEXIbility and CONstraints in life histories
  • DISCOVERY-CEMI: Circumpolar Ecosystems; Modelling and Integration

Data Activity or Cruise Information

Cruise

Cruise Name JR20090310 (JR200, JR200A, JR208)
Departure Date 2009-03-10
Arrival Date 2009-04-17
Principal Scientist(s)Rebecca Korb (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