TMSI/IDM/SISMER Sept 2000

SISMERSISMER Systèmes d’Informations 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 + VisualQC0 : Format, Codes, Completeness of InformationQC1 : Date, Time, Location, DuplicatesQC2 : Data PointsResult : 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/ocean/) 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

0 1 2 3 4 5 9No QC Correct Inconsistent Doubtful Bad Changed Missing

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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

Automatic Checks Results - Flag

Duplicate data sets EliminationDate Elimination or 5 Ship/Platform velocity Elimination or 5Location/shoreline Elimination or 5Bottom sounding (ETOPO5) Elimination or 3

5 = Correction/Interpolation 3 = doubtfull depth

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QC2 - Control of the Data points

Automatic Checks Results/Flag

Pressure record only EliminationOut of the regional scale 4 (min & max values)Non Increasing pressure 4Data below the bottom depth 4Coherence with pre-existing statistics (LEVITUS, REYNAUD, MEDATLAS) 2

Constant profiles 4Spikes - Gradient 3Vertical instability > noise 4

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QC2 - Control of the Data pointsMinimum & Maximum - Broad Range Check

0

200

2000

6000

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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 flag=4 at this point if none flag=4 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 < 100 m : 5 standard deviations

Shelf Stations 200< bottom < 400 : 4 standard deviations

Deep Stations bottom > 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