SISMER Systmes dInformations Scientifiques pour la Mer FNODC

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SISMER Systèmes dInformations Scientifiques
pour la Mer F-NODC
Quality Control Procedure at IFREMER Argo data
management meeting Brest 03-05/10/2000
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Quality Checks Automatic Visual

• QC0 Format, Codes, Completeness of Information
• QC1 Date, Time, Location, Duplicates
• QC2 Data Points
• Result Elimination or Quality Flag from GTSPP
  Scale
• References
• UNESCO/COI/IODE Manual of Quality Control
  Procedures for validation of Oceanographic Data -
  Manuals and Guides 26 - (GTSPP chapter)
• ICES -GETADE Formatting Guidelines for
  Oceanographic Data Exchange (http//www.ices.dk/oc
  ean/)
• ICES -MDM QA Guidelines - CTD - Marine Data
  Management working Group (CIEM) Reports
• UNESCO/IOC/IODE GF3 A General Formatting System
  for Geo-Referenced Data - Manual and Guides 17

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QC0 - FORMATS, CODES, INFORMATION

• Check of Meta-Data/Information RDBS - ORACLE
• Present Input Format for full QC
• autodescriptive ASCII (MEDATLAS)
• NetCDF (in preparation)
• Other input formats (Via conversion interfaces)

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QC1 Control of the location and Date - Data
collected in station
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QC2 - Control of the Data points
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QC2 - Control of the Data pointsMinimum
Maximum - Broad Range Check
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QC2 - Control of the Data pointsRegional
Adjustment for Broad Range Checks
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QC2- Vertical Stability Check

• Threshold noise for instability detection
• 0.03 in sigma-t for high resolution deep water
  stations
• 0.05 to 0.1 for coastal or low resolution
  stations
• 4 data points to be checked 2 levels T, S
• Automatic seach for further anomaly
• if any flag4 at this point
• if none flag4 at the 4 points and manual decision

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QC2 - Spike and Gradient Checks

• On 2 consecutive points at the top and bottom
• On 3 consecutive points in between
• Threshold for detection adjustable in
  geographical subregions and vertical layers

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QC2- Climatological Checks

• Several available climatologies Levitus 94, 98,
  Reynaud, Medatlas, MODB
• Default Climatology is Levitus 98 1x1 degree
• Allowed Variability
• Shallow water stations bottom lt 100 m 5
  standard deviations
• Shelf Stations 200lt bottom lt 400 4 standard
  deviations
• Deep Stations bottom gt 400 m 3 standard
  deviations

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Visual Checks

• Check of the Internal Coherence
• QC1 Check of the route or trajectory
• QC2 Internal coherence of the values and search
  for shifts or gaps
• Check of the External Coherence
• QC1 Display of all the profiles of another
  cruise/trajectory if at least one station is in
  the space/time vicinity
• QC2 Possibility of superposing the profiles
  made during another experiment in the same region
  
• Removing Doubts
• Vertical intabilities
• Spikes
• Climatological test (Erroneous climatological
  standard deviations)

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QC1 Control of the location and Date VISUAL
CHECKS - Data collected in station
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QC1 Control of the location and Date - Time
series on fixed mooring
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QC2 - Control of the Data pointsVisual Checks
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QC2 - Control of the Data pointsVisual Checks -
case of problematic climatology