Meteorology: Understanding the Atmosphere            Ackerman and Knox

Ice-containing clouds vary greatly in terms of the number, size, and shape of the ice crystals in them. The size and shape of a crystal is called its crystal habit. Temperature determines the particular crystal habit of ice. Use this applet to grow a snowflake and explore the relationship between crystal shape and environment temperature.

If you collect snowflakes on the ground, do you think you can recover the temperature of the environment they grew in?

Snowflake and cloud images by S.V. Medaris. Applet by Tom Whittaker. Physics adapted from K.C. Young Microphysical Processes In Clouds Oxford Univ Press (1993), and from Bob Crowder, The Wonders of the Weather Australian Govt Publishing Service (1995).