Cloud Variables

1. X Top pressure Cloud Variables Cloud type Effective radius Particle phase X Particle shape Optical thickness X Cloud cover/cloud detection Liquid water Bottom pressure

2. Bottom pressure/heigth • A chi serve? Aviazione, bilancio radiativo (LW bottom) • Come si stima? - Spessore (topmolecolare-topO2) - LWC - Tipo (climatologia) - cloud radar

5. Cloud type • A chi serve

7. +

8. g = 0.85 = 0.86 = 0.87 + Bidirectional reflectance Optical thickness

9. Ice particle habit • A chi serve

10. 25 July 2002 (VIPS) 25 July 2002 (VIPS) CPI: 7 July 2002 Ice Cloud MicrophysicsCRYSTAL-FACE, A. Heymsfield S. Platnick, ISSAOS ‘02

11. Ice cloud microphysics, cont.

12. MODIS ice crystal library habits/shapes S. Platnick, ISSAOS ‘02

13. Yang et al., “Single-scattering properties of complex ice crystals in terrestrial Atmosphere”, Contr. Atmos. Phys., 71, 223-248, 1998.

14. Effective radius and optical thickness

15. CLM: Cloud microphysical properties

16. mod05

17. Retrieval of tcand re Liquid Water Clouds - ocean surface • The reflection function of a nonabsorbing band (e.g., 0.86 µm) is primarily a function of optical thickness • The reflection function of a near-infrared absorbing band (e.g., 2.14 µm) is primarily a function of effective radius • clouds with small drops (or ice crystals) reflect more than those with large particles • For optically thick clouds, there is a near orthogonality in the retrieval of tc and re using a visible and near-infrared band

18. Retrieval of tcand re Ice Clouds - ocean surface • The reflection function of a nonabsorbing band (e.g., 0.86 µm) is primarily a function of optical thickness • The reflection function of a near-infrared absorbing band (e.g., 2.14 µm) is primarily a function of effective radius • clouds with small drops (or ice crystals) reflect more than those with large particles • For optically thick clouds, there is a near orthogonality in the retrieval of tc and re using a visible and near-infrared band

19. Cloud Optical & Microphysical Properties Retrieval Example Liquid Water Clouds - ocean surface Liquid Water Clouds - ice surface

20. g = 0.85 = 0.86 = 0.87 Multiple scatteringwater cloud examples reflectance vs. asymmetry parameter (g) 1-v0 = 0 Bidirectional reflectance Optical thickness g = < cos(Q) p(Q)> ~ re S. Platnick, ISSAOS ‘02

21. g = 0.85 = 0.86 = 0.87 Multiple scattering - reflectancewater cloud examples reflectance vs. asymmetry parameter (g) reflectance vs. 1-v0 (R ~1-v0N) 1-v0 = 0 1-v0 = 0 g = 0.85 1-v0 = 0.006 Bidirectional reflectance 1-v0 = 0.020 1-v0 = 0.006 Optical thickness Optical thickness g = < cos(Q) p(Q)> ~ re 1-v0are S. Platnick, ISSAOS ‘02

22. Ship track schematic courtesy, P. Durkee N ~ 40 cm-3 W ~ 0.30 g m-3 re ~ 11.2 µm N ~ 100 cm-3 W ~ 0.75 g m-3 re ~ 10.5 µm S. Platnick, ISSAOS ‘02

23. Level-1B Image of California Stratus with Ship Tracks April 25, 2001 marine stratocumulus Red = 0.65 µm Green = 0.56 µm Blue = 0.47 µm

24. Level-1B Image of California Stratus with Ship Tracks April 25, 2001 3.7 µm band Red = 0.65 µm Green = 0.56 µm Blue = 0.47 µm

25. CLM: Cloud microphysical properties • Cloud effective droplet radius • Cloud optical thickness

26. Cloud phase

28. IR thermodynamic phase retrieval(B. Baum, S. Ackerman, S. Nasiri, NASA LaRC, U. Wisconsin/CIMSS) ice water Absorption coefficient (cm-1) ice 16.7 14.3 12.5 11.1 10.0 9.1 8.3 µm S. Platnick, ISSAOS ‘02

29. Nasiri et al., 2002 S. Platnick, ISSAOS ‘02

30. Effect of multilayered clouds Bispectral IR algorithm Uncertain Mixed Phase Ice Liquid Water No Retrieval S. Platnick, ISSAOS ‘02

31. CLP Cloud phase

32. Ice/Water Clouds Separate in 8.6-11 vs 11-12 um BT plots

33. Cloud Composition Contrails MODIS Image Over Kansas - 21 April 1996 Ice Cloud Infrared Temperature Difference - 8.6 m (Band 29) - 11.0 m (Band 31) Contrails Water Cloud Infrared Temperature Difference - 11.0 m (Band 31) - 12.0 m (Band 32)