Tuesday, January 19, 2010

Frost


Hoar frost on chicken wire

photos by Dave Ellison

Yesterday, the world was wrapped in fog. Frost crystals grew on everything, on the fence wires, on the trees, even on the black guard hairs on Sasha the goat’s back.

Frost is a pretty amazing form of water. Water vapor in the air forms on surfaces that are colder than the surrounding hair. Earlier in the week, on a cold, clear night, hoar frost formed long, elegant crystals on chicken wire, fence lines, and tree branches. Hoar frost crystals form on imperfections, scratches on the fence wire, or the tips of the barbs on barbed wire, or on the smallest twigs on trees. The woods were a feathery fairyland. In the cold morning, the frost remained even as the sun warmed the world.

Yesterday morning, the temperature was a balmy 18 ˚ F. The frost this morning was more like rime, an icy, solid surface that forms during fogs. There were no beautiful crystals, but white still coated everything, like a glove, even the tendrils of my hair that drifted around my face as I fed the sheep.

2 comments:

  1. Nice pictures, I never heard the word rime before.

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  2. 如果你批評他人。你就沒有時間付出愛.........................

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