Argo Real-time Quality Control Process NOAA/AOML: Y.-H. DANESHZADEH, R. MOLINARI, R. SABINA, C. SCHMID CIMAS/UM: E. FORTEZA, X. XIA, H. YANG

Guiding Philosophy of the international real-time DACs PROVIDE TO THE INTERNATIONAL OPERATIONAL AND RESEARCH OCEANIC COMMUNITIES PROFILES OF TEMPERATURE AND SALINITY RESULTING FROM ARGO FLOATS THAT MEET THE FOLLOWING CRITERIA:  DATA HAVE BEEN MANAGED IN A UNIFORM MANNER  DATA ARE FREE  DATA ARE READILY ACCESSIBLE  DATA ARE AVAILABLE WITHIN A TIMELY MANNER  DATA HAVE BEEN QUALITY CONTROLLED TO REMOVE THE MOST EGREGIOUS ERRORS  COST OF REAL TIME QUALITY CONTROL IS REASONABLE

Number of profiles quality controlled per year

Positions of the floats that have delivered data within the last 30 days Atlantic Data Coverage

How an Argo float works

Data flow

Real-time processing system

Delayed-mode processing system

Automatic quality control 1.Platform Identification 2.Impossible Date (valid & not before 1997) 3.Impossible Location (-180 to 180, -90 to 90) 4.Position on Land (ETOPO5) 5.Impossible Speed (<=3m/s) 6.Global Range (-2.5 to 40C, 0 to 41 psu) 7.Regional Range (Red Sea, Mediterranean Sea) 8.Pressure Increasing 9.Spike (| V2 - (V3 + V1)/2 | - | (V3 - V1) / 2 ) Documents are at

Regional Range tests, definitions Red Sea  Temperature in range 21.7 to 40.0 o C  Salinity in range 0.0 to 41.0 Mediterranean Sea  Temperature in range 10.0 to 40 o C  Salinity in range 0.0 to 40.0

temperature Spike test examples Multiple-value spikes can be a problem. level temperature salinity

Automatic quality control 10.Top and Bottom Spike (no top spike test, bottom spike test currently under development) 11.Gradient (| V2 - (V3 + V1)/2 |) 12.Digit Rollover test (part of decoders) 13.Stuck Value (e.g. all values of T the same) 14.Density Inversion (gradient must be >=0) 15.Grey List (decided by PI & Operator) 16.Gross Salinity or Temperature Sensor Drift Test (checks if values in the deep ocean change too much, dT >1 o C, dS >0.5 psu) Documents are at

Bottom spike examples Currently no test is available to detect this problem.

Gradient test examples If spikes are not excluded prior to application, then the test may flag some good points as bad. salinity level

Density inversion test examples Flags wrong point because of three bad values around a good one. Current version: top to bottom.

Density inversion test examples One flag at wrong point because of three bad values around a good one. New version: top to bottom and bottom to top.

Automatic quality control 17.Visual QC: at AOML currently triggered by failure of any of the other tests on the profile data (except for grey list test). Additionally triggered by climatology/reanalysis test. 18.Frozen profile (>=5 almost identical consecutive profiles). 19.Deepest pressure test: pressure may not exceed nominal profile pressure given in the meta file by more than 10%. Documents are at

Visual quality control Two cases of bad profiles that can not be detected by the standard Argo QC tests. For these a climatology test that triggers a visual QC can be very helpful. level temperature salinity

Blue circles indicate that T (top) or S (bottom) failed the test. Results of frozen profile test Profile number pressure

Quality control statistics

US Argo DAC web page at AOML