Formation of Ice Crystals
The most common way to form an ice crystal, starts with an ice nucleus in the cloud. Ice crystals can form from heterogeneous deposition, contact, immersion, or freezing after condensation. In heterogeneous deposition, an ice nucleus is simply coated with water. For contact, ice nuclei will collide with water droplets that freeze upon impact. During immersion, an ice nucleus will hit a water droplet and instantly freeze it. Water can also condense onto ice nuclei and then freeze.
Water will freeze at different temperatures depending upon the type of ice nuclei present. Ice nuclei cause water to freeze at higher temperatures than it would spontaneously. For pure water to freeze spontaneously, called homogenous nucleation, cloud temperatures would have to be -42 degrees Celsius. Here are some examples of ice nuclei:
| Ice Nuclei | Temperature to Freeze (degrees C) |
|---|---|
| Bacteria | -2.6 |
| Kaolinite | -4 |
| Silver Iodide | -7 |
| Vaterite | -9 |
Read more about this topic: Bergeron Process
Famous quotes containing the words formation of, formation, ice and/or crystals:
“... the mass migrations now habitual in our nation are disastrous to the family and to the formation of individual character. It is impossible to create a stable society if something like a third of our people are constantly moving about. We cannot grow fine human beings, any more than we can grow fine trees, if they are constantly torn up by the roots and transplanted ...”
—Agnes E. Meyer (1887–1970)
“It is because the body is a machine that education is possible. Education is the formation of habits, a superinducing of an artificial organisation upon the natural organisation of the body.”
—Thomas Henry Huxley (1825–1895)
“Not to like ice cream is to show oneself uninterested in food.”
—Joseph Epstein (b. 1937)
“It is clear that everybody interested in science must be interested in world 3 objects. A physical scientist, to start with, may be interested mainly in world 1 objects—say crystals and X-rays. But very soon he must realize how much depends on our interpretation of the facts, that is, on our theories, and so on world 3 objects. Similarly, a historian of science, or a philosopher interested in science must be largely a student of world 3 objects.”
—Karl Popper (1902–1994)