Rutherford Appleton Laboratory PM2 MSG cloud model 17 th February 2008 Comparisons with Calipso and Cloudsat C. Poulsen R.Siddans

Aims Verify the RAL retrieval scheme Asses the skill of the retrieval scheme in real life scenarios Asses the feasibility to use information on cloud top pressure etc from the surrounding area Use the retrievals as case studies to asses the success of the new retrieval scheme

Data Single orbit 13 th of June 2008 –Processed by OCA –Processed by RAL Calipso 5km layer product Cloudsat 5km CPR product SEVIRI matched to ±5km of Calipso track Histograms plotted for a region ±50km around the calips track

Differences between OCA and RAL product Retrievals are run in single layer mode RAL retrieval does not include cloud fraction in the state vector RAL retrieval does separate retrievals for ice and water and chooses the phase based on lowest cost –Hence ice crystal sizes can be very small –Baran optical properties used but could easily use Baum Might be useful to have OCA residual information ]

OCA retrieval

RAL retrieval

OCARAL

OCA RAL

OCA RAL

Conclusions RAL and OCA show good agreement where expected Both Calipso and Cloudsat are useful to validate the retrieval success –Possible collocation problems between Calipso and Cloudsat? Potential cases studies identified Comparisons suggest that the surrounding information can be used to constrain/correlate the multi-layer retrievals –But further statistical analysis required.