Effect of GSICS calibration on CM SAFs cloud
Effect of GSICS calibration on CM SAF‘s cloud products Anke Kniffka – CM SAF team DWD 21 September 2010 EUMETSAT Conference, Cordoba, Spain
Calibration of SEVIRI IR channels with the help of IASI Applied in this case for MSG 2 Data retrieved from Eumetsat‘s web portal 21 September 2010 EUMETSAT Conference, Cordoba, Spain
GSICS calibration curve 21 September 2010 EUMETSAT Conference, Cordoba, Spain
Effect on radiance for several channels Tested on one month of SEVIRI slots (March 2009), hourly resolution Calibration for MSG 2, channels: 3. 9, 6. 2, 7. 3, 8. 7, 9. 7, 10. 8, 12. 0, 13. 4 in use: all but … There also visible channels used in cloud detection! 21 September 2010 EUMETSAT Conference, Cordoba, Spain
21 September 2010 EUMETSAT Conference, Cordoba, Spain
21 September 2010 EUMETSAT Conference, Cordoba, Spain
Products are: CFC, CTY, CTTPH Temporal resolution: instantaneous (hourly) and daily mean data 21 September 2010 EUMETSAT Conference, Cordoba, Spain
Cloud Fractional Cover: daily mean original 21 September 2010 calibrated EUMETSAT Conference, Cordoba, Spain
Negative values: More clouds with calibration 21 September 2010 EUMETSAT Conference, Cordoba, Spain
21 September 2010 EUMETSAT Conference, Cordoba, Spain
Cloud mask: statistics individual slot data for March 2009 original calibrated o Some pixel are flagged as clear now (cloudy before), about twice as much crop up (clear before) o Equally distributed in space 21 September 2010 EUMETSAT Conference, Cordoba, Spain
Cloud fraction for different cloud types (based on daily mean for March 2009) original calibrated o More cloudy pixel o Noticeable rise of high semitransparent cloud class 21 September 2010 EUMETSAT Conference, Cordoba, Spain
original calibrated No calibration for visible channels so far -> effect on thresholds for cloud type determination 21 September 2010 EUMETSAT Conference, Cordoba, Spain
CTH: neg. values refer to higher clouds with calibration 21 September 2010 EUMETSAT Conference, Cordoba, Spain
21 September 2010 EUMETSAT Conference, Cordoba, Spain
To sum up: º Need for calibration in visible channels → Can cause problems with consistency º Validation with ground based data will be carried out 21 September 2010 EUMETSAT Conference, Cordoba, Spain
- Slides: 16