Operational Data Checking

An automatic data checking system has been implemented at ECMWF to trigger warnings in case of anomalies affecting the quality or the availability of the data assimilated by the model. Selected statistical parameters (number of observations, bias correction, and mean bias-corrected background, analysis departures and probability of gross error) are checked against an expected range. An appropriate alert message (including a time series plot) is generated if statistics are outside the specified ranges. A severity level (slight, considerable, severe) is assigned to each message depending on how far statistics are from the expected values. Two kinds of ranges are used by the automatic checking: Soft and Hard limits. Soft limits are updated automatically using statistics from the last twenty days (extremes are excluded during this process). Hard limits are adjusted manually when required.

Currently, the automatic checking is limited to data passing through the minimisation process (including VarBC passive data). It's being applied twice a day to the delayed cut-off 4D-VAR cycles (00 and 12) and four times a day to the early delivery assimilation system (00,06,12 and 18).

The alarm system results are based on feedback information from the ECMWF data assimilation and consequently reflect the ECMWF data usage. Although most warnings are related to data problems, they may on occasion also be related to model issues. Alerts are provided for information on an as-is basis and may be withdrawn or changed without notice. ECMWF accepts no responsibility for actions taken on the basis of these results.

Ensemble Data Assimilation at 2021-02-20 00:00

amsua
METOP-A AMSUA RADIANCES (8 channels affected) : out of range
Considerable: obs_number=6342.0000, expected range: 7030.2918 8516.0832
cris
NOAA20 CRIS RADIANCES (28 channels affected) : out of range
Considerable: obs_number=2496.0000, expected range: 2200.8355 2323.5395
NPP CRIS RADIANCES CHANNEL 177 : out of range
Slight: avg_fgdepar=0.0451, expected range: 0.0181 0.0396
mhs
METOP-A MHS ALLSKY RADIANCES CHANNEL 5 : out of range
Considerable: obs_number=5481.0000, expected range: 13184.2830 18483.8420
METOP-A MHS ALLSKY RADIANCES CHANNEL 4 : out of range
Considerable: obs_number=6892.0000, expected range: 16739.8327 23248.0423
METOP-A MHS ALLSKY RADIANCES CHANNEL 3 : out of range
Considerable: obs_number=6936.0000, expected range: 16732.4400 23342.1850
ssmis
All DMSP-17 SSMIS ALL CHANNELS Global : all data missing
Severe: obs_number=0, expected range: 6695.39 20198.83
All DMSP-18 SSMIS ALL CHANNELS Global : all data missing
Severe: obs_number=0, expected range: 6759.48 19798.00
gpsro
COSMIC2-E3 GPSRO SETTING HEIGHT 48-50 KM : out of range
Slight: avg_norm_fgdepar=-0.2283, expected range: -0.1510 0.0269
amdar
All AMDAR ALL LAYERS South Atlantic : all data missing
Severe: obs_number=0, expected range: 52.01 278.88