SME
Meteorology · Problem type
The ice-crystal (Bergeron) process
Use this for “Explain how snow and most mid-latitude rain form in a cloud colder than 0 °C.”
Put in order
Put the stages of the ice-crystal process in order.
1
?
2
?
3
?
4
?
5
?
Assumptions
•
Droplets stay liquid (supercooled) down to about −40 °C unless they freeze on an ice nucleus.
•
Over ice the saturation vapor pressure is lower than over water, so ice grows while droplets shrink.
•
In warm clouds, as in the tropics, rain forms by collision and coalescence instead.
Topic check
See what you know: 5 questions on this topic
New questions each time. Pass to mark it complete.
Related lessons
Clouds and precipitation
Main lesson
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Cloud genus from height and form
Use this for “A thin white veil makes a halo around the Sun. Is it a high, middle or low cloud, and which genus?”