1. Using satellite simulators for cloud evaluation
Keith Williams
WGNE31, 27/04/16
© Crown copyright Met Office

2. CloudSat CALIPSO ISCCP MODIS MISR (RTTOV)
CFMIP web: cfmip.metoffice.com/COSP.html
User group: groups.google.com/group/cosp-user
© Crown copyright Met Office
(Bodas-Salcedo et al., BAMS, DOI: /2011BAMS )

3. Bias in cloud cover (against CALIPSO – cloud lidar)
© Crown copyright Met Office

4. Tropics
© Crown copyright Met Office

5. Comparison against satellite data over the tropics
ISCCP
CALIPSO
CloudSat
Excess hydro-meteor at low levels
Too little medium brightness cloud
Excessive cirrus and too low
© Crown copyright Met Office
Excess “drizzle” (<0.005mm/hr)

6. Comparison against satellite data over the tropics
ISCCP
CALIPSO
CloudSat
Reduced cirrus spreading rate
© Crown copyright Met Office
6A convection
Warm rain microphys

7. Case study VT: 18Z 17/12/2010 (T+6)
© Crown copyright Met Office

8. CALIPSO composites (mean over tropics)
By SST:
Cool
Warm
By vertical velocity:
Strong subsidence
Strong ascent

9. Mid-latitude storm tracks
© Crown copyright Met Office

10. Case study VT: 15Z 16/02/2011 (T+27)
© Crown copyright Met Office

11. Composite cyclone: RL-GEOPROF hydrometeor frac.
Northern hemisphere winter
Following Govekar et al. (2014)
(cyclone compositing using Field and Wood, 2007)

12. Composite cyclone: GA6 hydrometeor frac bias
Northern hemisphere winter
© Crown copyright Met Office

13. Composite cyclone: GA7 hydrometeor frac bias
Northern hemisphere winter
© Crown copyright Met Office

14. Composite cyclone: GA6 cloud albedo bias
Winter
Summer
Northern hemisphere:
Southern hemisphere:
© Crown copyright Met Office

15. Discussion
At the Met Office, we have found satellite simulators extremely valuable for model development.
The climate community conduct routine comparisons of satellite simulator output as part of CFMIP. The diagnostics are requested as standard in CMIP.
Is COSP typically being used within NWP centres?
Would it be useful for a similar inter-comparison to be undertaken amongst NWP models?
Comparison against current instruments is best before Is it too difficult to re-run forecasts for this period (no need to re-run DA)?
Is it best to start now (and get improving models) or wait for EarthCARE (~2018)?
© Crown copyright Met Office

16. © Crown copyright Met Office