Hair today, gone tomorrow!

A rarity to look out for in the current frosty weather.

Last night at the PNHS meeting, Nigel Scriven, showed a photo of the Hair ice he and Catriona spotted at Bank Brae woods, Glentyan, Kilbarchan, on 8th January. Here’s his photo of it, quite a remarkable sight.

Hair ice requires very specific conditions to form and so is rarely seen. It forms on moist rotting wood of several species of deciduous trees, but only when the air is humid and temperature slightly below 0 °C, . Not only that, but it requires the presence of a specific fungus in the wood, Exidiopsis effusa.

Water present in the wood freezes and creates a barrier trapping liquid between the ice and the pores in the wood. This causes a suction pushing water out of the pores to the ice surface where it freezes and extends outwards. As this repeats a thin ‘hair’ of ice around 0.02mm, the diameter of the pores, is pushed out of the wood. Traces of the metabolic products of the fungus feeding on the wood are thought to act a little like anti-freeze proteins, preventing big crystals forming on the surface of the wood and also acting as a stabilising agent. The result is masses of fragile silken threads of ice which can grow up to 20cm in length if freezing temperatures continue and it is left untouched.

Thanks to Nigel and Catriona for sharing their amazing find with us.