TMSI/IDM/SISMER Sept 2000 SISMER SISMER Systèmes d’Informations Scientifiques pour la Mer F-NODC Quality Control Procedure at IFREMER Argo data management meeting Brest 03-05/10/2000

2 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 l UNESCO/COI/IODE : Manual of Quality Control Procedures for validation of Oceanographic Data - Manuals and Guides 26 - (GTSPP chapter) l ICES -GETADE Formatting Guidelines for Oceanographic Data Exchange ( l ICES -MDM QA Guidelines - CTD - Marine Data Management working Group (CIEM) Reports l UNESCO/IOC/IODE : GF3 A General Formatting System for Geo-Referenced Data - Manual and Guides No QC Correct Inconsistent Doubtful Bad ChangedMissing

3 QC0 - FORMATS, CODES, INFORMATION l Check of Meta-Data/Information : RDBS - ORACLE l Present Input Format for full QC : l autodescriptive ASCII ( MEDATLAS ) l NetCDF (in preparation) l Other input formats (Via conversion interfaces)

4 QC1 Control of the location and Date - Data collected in station Automatic ChecksResults - Flag Duplicate data setsElimination Date Elimination or 5 Ship/Platform velocity Elimination or 5 Location/shoreline Elimination or 5 Bottom sounding (ETOPO5) Elimination or 3 5 = Correction/Interpolation 3 = doubtfull depth

5 QC2 - Control of the Data points Automatic Checks Results/Flag Pressure record only Elimination Out of the regional scale 4 (min & max values) Non Increasing pressure 4 Data below the bottom depth 4 Coherence with pre-existing statistics (LEVITUS, REYNAUD, MEDATLAS) 2 Constant profiles 4 Spikes- Gradient 3 Vertical instability > noise 4

6 QC2 - Control of the Data points Minimum & Maximum - Broad Range Check

7 QC2 - Control of the Data points Regional Adjustment for Broad Range Checks

8 QC2- Vertical Stability Check l Threshold noise for instability detection l 0.03 in sigma-t for high resolution deep water stations l 0.05 to 0.1 for coastal or low resolution stations l 4 data points to be checked : 2 levels T, S l Automatic seach for further anomaly l if any flag=4 at this point l if none flag=4 at the 4 points and manual decision

9 QC2 - Spike and Gradient Checks l On 2 consecutive points at the top and bottom l On 3 consecutive points in between l Threshold for detection adjustable in geographical subregions and vertical layers

10 QC2- Climatological Checks l Several available climatologies : Levitus 94, 98, Reynaud, Medatlas, MODB l Default Climatology is Levitus 98 1x1 degree l Allowed Variability ã Shallow water stations bottom < 100 m : 5 standard deviations ã Shelf Stations 200< bottom < 400 : 4 standard deviations ã Deep Stations bottom > 400 m : 3 standard deviations

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

12 QC1 Control of the location and Date VISUAL CHECKS - Data collected in station

13 QC1: Control of the location and Date - Time series on fixed mooring

14 QC2 - Control of the Data points Visual Checks

15 QC2 - Control of the Data points Visual Checks - case of problematic climatology