Satellite Evaluation work at Reading

Julien Delanoë/Thorwald Stein/Robin Hogan

Collaborations: Richard Forbes (ECMWF)/

Alejandro Bodas-Salcedo (MetOffice)

Cloud/radar/radiation collaboration meetingHow best can we work together to evaluate model changes

17-18 November in Reading

What do we do from space?Evaluation of cloud representation in models

We retrieve cloud fraction and cloud properties• Ice clouds/precip (Julien/Thorwald/Robin)Ice cloud fraction/frequency of occurrence/IWC/IWP

• Mixed phase clouds (Julien/Robin)Supercooled water fraction

UM+Simulator vs CloudSat (Thorwald)40km

Same Z threshold

OLD: old PSD parameterisationNEW: new PSD parameterisation, consistent with UM

Model, narrower distribution.

Why does the new model show a shifted distribution to the small Z?The inconsistent param does not look closer to CloudSat

40km

Obs

Lat

Temperature

12km

40km

Indo-Pacific 9-16 Oct 08V

ertic

al d

istr

ibut

ion

Horizontal distribution

New PSD

Frequency of Occurrence of iceMore ice clouds in models!

UMIWC narrower distributionHigher IWCHigher IWP

ECMWFSimilar dist but lack of low T cloudsBetter agreement than UM for IWP

Mixed phase cloudsJanuary to December 2007

Z-Z

top

()km

Conclusion

• Data availability:– Cloud mask, entire period of CloudSat/CALIPSO– Ice properties: 1,5 years (all 2007)

• What would modellers need to improve Cloud representation in GCM?

For discussion

All

NorthPole

NorthernMidlats

SouthernMidlats

Tropicalbelt

SouthPole

Supercooled layer