Researchers from Switzerland and Germany have finally managed to understand how hair ice is forms. Hair ice is met in northern climates on rotten branches and wood. It is a phenomenon which occurs during winter time when you can notice silky hairs with the texture of candy floss growing on certain trees.
One of the authors of the study, Christian Mätzler from the University of Bern in Switzerland, the Institute of Applied Physics, explained that they were mesmerized by the ice hair when they saw it for the first time on a forest walk. Out of curiosity the researchers decided to examine this phenomenon.
At first they conducted some simply experiments such as simply letting the ice melt in their hands. Biologist Gisela Preuß from Wiedtal-Gymnasium (Neustadt, Wied) used a microscopic technique and managed to identify eleven different types of fungi. However one of the species, namely Exidiopsis effusa, was reported to be the one which colonizes all of the wood which produces hair ice. Moreover in more than half of the samples Exidiopsis effusa was the only one present.
Mätzler explained that because of the fact that the freezing front is placed at the mouth of the wood rays they are the ones which determine the shape of the growing hair ice. Irrespective of the fungal activity the wood still has the same amount of ice. However without the help of the fungal activity it would not have a magical texture and shape. It would instead have a crust-like structure.
Diana Hoffman, a chemist from the Institute of Bio and Geosciences in Germany examined the chemical compounds of the melted ice water and identified traces of tannin and lignin which represent metabolic byproducts of fungal activity. According to her these might be the chemical compounds which do not allow the formation of big ice crystals at the wood surface.
What the fungus does is enable the ice to form thin hairs which have the diameter of around 0.01 mm. it also allows the ice to maintain this shape for a long period of time if the temperature is around 0°C. The researchers speculate that the ice hairs are preserved by a recrystallization inhibitor which is created by the fungus.
Image Source: hislambsonline.org