1. Cirrus microphysical and radiative properties
Steven Dobbie

2. Progression: Radiative Transfer Optical Properties GCM Modelling
Cloud Modelling

8. Importance of cirrus: - Albedo effect (iris effect)
- Radiation-convection feedback
- Precipitation
- Indirect effects

10. Research developments:
Sat Ghosh Radiative properties of
inhom cirrus (CWVC)
(May ’03).
John Marsham Shear effects on cirrus
clouds (EMERALD)
(April ‘03).
Adrian Hill Semi-direct/indirect effects bin resolved LES (warm) (Oct ‘02).
Clare Allen Iris effect of cirrus on climate (Oct ‘03).
Gourihar Kulkarni Aerosol mixtures.
Environmental Chamber (Oct ‘03).

11. Collaborations: - Laki eruption - Highwood (Reading)
- Stevenson (Edinburgh)
- Contrails (FP6)
- Mannstein (DLR)

12. UK LES modelling

15. (z,t)/z + (/Tv) ((z,t)/z) t < 0 (z,t)/z
Radiation and latent stability numbers
(z,t)/z + (/Tv) ((z,t)/z) t < 0
(z,t)/z
Rsn =
(/Tv) ((z,t)/z) t
For Radiative Instability 0 < Rsn < 1

17. Modelling cirrus: - Driving mechanisms - Microphysics
- Aerosol influences
- Sub-grid variability
- Radiative properties
- Climate feedback mechanisms

18. Sub-grid cloud inhomogeneity
GCM Grid cell km