2. Fog
Cloud base is on the ground
Radiational cooling of the ground

4. Stratocumulus Sun shining through breaks in cloud layer Base < 2km
“Low Cloud”
Sun shining through breaks in cloud layer

5. Low Clouds (bases <2 km above ground)

6. Marine stratocumulus

7. Marine stratocumulus

9. Cumulus
‘heaped’

10. All Convective Clouds Buoyancy phenomena Turbulent Vorticity
Condensation level

11. Development of Cumulus Congestus

12. Cumulus congestus develops into a cumulonimbus
Heavy rain, thunder, lightning

13. Three smallest members of the cumulus family
Cumulonimbus
Cumulus congestus
Cumulus
Bases <2 km above ground)

14. Biggest member of the cumulus family: “Mesoscale Convective System”
High cloud top extends over huge area
Hurricane Rita
Cloud is thick, lots of precipitation falling

16. Altocumulus Like Stratocumulus except elevated to midlevels
Base 2-7 km
“Middle Cloud”
Like Stratocumulus except elevated to midlevels

18. Cirrus
Base > 7 km
“High Cloud”
All ice because it’s too cold for liquid water to survive at these altitudes

20. Mountain Wave Cloud
Airflow

21. Mountain Wave & Lee Wave Clouds

22. Unusual wave clouds

23. Unusual wave clouds
Wave clouds on Mars
Island wake cloud in marine Sc

24. Extratropical Cyclone
Nimbostratus
Extratropical Cyclone

25. Nimbostratus Base < 2km “Low Cloud”
Rain obscures view of the more distant islands

26. Low Clouds (bases <2 km above ground)
The prefix “nimbo-” or suffix “-nimbus” means precipitating

27. International Cloud Classification
Luke Howard 1803
Jean Babtiste Lamarck 1802
Goethe,” In Honour of Howard”,” Howards Ehrengedaechtnis”, translated into English by Huettner (John Hennig, Modern Language Quarterly 1951)
Fog
Orographic clouds
Mesoscale and synoptic-scale storm clouds (MCSs, frontal cloud systems, tropical cyclones
Additional categories

28. ISSCP-type Satellite Cloud Classification
Cloud Top Pressure (mb)
Cloud Optical Thickness
Optical thickness = tau, where transmitted/incident = exp (-tau)
Rossow 1999