Hair Ice

Environmental & Science Education, STEM, Earth & Space Science, Earth Systems, Nature

Ed Hessler

Hair ice. Ice wool. Frost beard.  I've never seen it and received a lovely introduction to it by Tamas Varga (Earthly Mission). 

It was interesting to learn that its formation is due to a fungus (Exidioposa effusa), a discovery made in 2015. This link, a Wiki entry, has the complete citation for the full scientific paper and access to a PDF. The mechanism that allows the formation as well as stabilizes it, once formed, is not certain. The ice hairs can be long lived and "can maintain their shaped for hours and sometimes even days."

This particular ice formation is not common and based on observations, it  appears to be a denizen of broadleaf forests "mostly at latitudes between 45 and 55 degrees N." I learned from Varga's reporting that the"ice forms on moist, rotting wood from broadleaf trees when temperatures are slightly under 0 °C (32 °F) and the air is humid. The smooth, silky hairs have a diameter of about 0.02 mm (0.0008 in) and a length of up to 20 cm (8 in). Although individual hairs are brittle, they usually take the shape of curls and waves." 

Another characteristic of their formation which is not yet fully understood is that they "appear to root at the mouth of wood rays (never on the bark), and their thickness is similar to the diameter of the wood ray channels."

Varga includes many take-your-breath away photographs.

At one point, Varga refers to this kind of ice as "white wig." I liked it and I think it is also a great alternative to be included in a list of common names.