Marine Data Quality Flags:
Quality Flag Tables
In all these systems, "QC" refers to
quality control procedures.
Argo
- 0 - No QC was performed
- 1 - Good data
- 2 - Probably good data
- 3 - Probably bad data that are potentially correctable
- 4 - Bad data
- 5 - Value changed
- 8 - Interpolated value
- 9 - Missing value
British Oceanographic Data Centre (BODC)
- Field left blank - Acceptable value
- < - 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
- 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 - Improbably value, BODC quality control
- N - Null value
European Sea Level Service (ESEAS)
- 0 - No quality control
- 1 - Correct value
- 2 - Interpolated value
- 3 - Doubtful value
- 4 - Isolated spike or wrong value
- 5 - Correct but extreme value
- 6 - Reference change detected
- 7 - Constant values for more than a defined time
interval
- 8 - Out of range
- 9 - Missing value
Global Temperature and Salinity Profile Program (GTSPP)
- 0 - No QC was performed
- 1 - QC was performed; good data
- 2 - QC was performed; probably good data
- 3 - QC was performed; probably bad data
- 4 - QC was performed; bad data
- 5 - The value was changed as a result of QC
- 9 - The value is missing
Ocean Data View Software
- 0 - Good quality
- 1 - Unknown quality
- 4 - Questionable quality
- 8 - Bad quality
PANGAEA
- Left blank - Valid
- ? - Questionable
- / - Not valid
- * - Unknown
- # - Individual definition
- > - Larger than
- < - Less than
Quality Assurance of Real-Time Oceanographic Data (QARTOD)
- 0 - Quality not evaluated
- 1 - Bad
- 2 - Questionable/suspect
- 3 - Good
- 9 - Missing data
SeaDataNet
- 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
Swedish Meteorological and Hydrological Institute (SMHI)
- Left blank - Good value
- ! - Extreme/suspicious value, checked manually and
compared with other relevant parameters and found correct
- ? - Questionable value
- B - Bad value
- < - Below detection limit/less than
- > - Above detection limit/greater than
- | - Manually interpolated/extrapolated
- C - Value from CTD temp/salin/fluor/oxyg
- Z - Zero by definition
WOCE CTD
- 1 - Not calibrated
- 2 - Acceptable measurement
- 3 - Questionable measurement
- 4 - Bad Measurement
- 5 - Not reported
- 6 - Interpolated over >2 dbar level
- 7 - Despiked
- 9 - Not sampled
WOCE
Bottle Samples
- 1 - Sample for this measurement was drawn from water
bottle but not received
- 2 - Acceptable measurement
- 3 - Questionable measurement
- 4 - Bad Measurement
- 5 - Not reported
- 6 - Mean of replicate measurements
- 7 - Manual chromatographic peak measurement
- 8 - Irregular digital chromatographic peak integration
- 9 - Sample not drawn for this measurement from this
bottle
World Ocean Database (Individual Observed Parameters)
- 0 - Accepted value
- 1 - Range outlier (outside of broad range check)
- 2 - Failed inversion check
- 3 - Failed gradient check
- 4 - Failed observed level "bull's-eye" check or
zero-gradient check
- This revised wording confirmed with the US NODC OCL,
2009-07-13
- 5 - Failed combined gradient and inversion checks
- This revised wording confirmed with the US NODC OCL,
2009-07-13
- 6 - Failed range and inversion checks
- 7 - Failed range and gradient checks
- 8 - Failed range and questionable data checks
- 9 - Failed range and combined gradient and inversion
checks
World Ocean
Database (Depths)
- 0 - Accepted value
- 1 - Duplicates or inversions in recorded depth (same or
less than previous depth)
- 2 - Density inversion
World Ocean Database (Entire Stations)
- 0 - Accepted station
- 1 - Failed annual standard deviation check
- 2 - Two or more density inversions (Levitus, 1982
criteria)
- 3 - Flagged cruise
- 4 - Failed seasonal standard deviation check
- 5 - Failed monthly standard deviation check
- 6 - Failed annual and seasonal standard deviation check
- 7 - Bull's-eye from standard level data or failed annual
and monthly standard deviation check
- 8 - Failed seasonal and monthly standard deviation check
- 9 - Failed annual, seasonal, and monthly standard
deviation check