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Name: jessica a scholten
Status: N/A
Age: N/A
Location: N/A
Country: N/A
Date: 1999


Question:
Here on the coast of B.C. we have a strange form of frost that developes on dead, barkless branches. It looks like fine white hair. What is it called and how is it formed?


Replies:
I have no idea what causes this but I can suggest an experiment to help you determine the cause. Ice needs a substrate (a surface) to precipitate on. I am guessing that the dead barkless branches are covered with a fungus or mold that is not easily seen until covered with frost. Try spraying an atomizer (from a perfume bottle) at the branches. If my idea is correct, the "hairs" will be revealed. It is important to use a very fine atomizer. You may also see the same effect if you place some hot steamy water under the branches. You could also clean some branches and see if they are able to support the growth of "hair".

Let everyone on NEWTON know what you find!

michael b lomonaco


Sounds like you are referring to hoar frost, which forms in calm, humid air, when water vapor in the air comes in contact with a frozen surface. The water vapor sublimates onto the surface, forming the frost. Sublimation means that instead of the vapor becoming liquid (water) and then solid (ice), the vapor forms a solid directly without ever being a liquid. One of the definitions of the word "hoar" is gray or white with age. Hoar frost was probably given this name because it looks like an old man's beard.

-Grant



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