Hair Ice

Something completely new to us—Hair Ice. On 27 January 2022, Erika and I explored Nisqually State Park, about 40 miles southeast of Olympia. When we left foggy Olympia, temperatures stood at 39° and steadily fell to 30°—perfect conditions for the formation of Hair Ice. But this story is more bizarre. Although Hair Ice has been known for a century, only in the last decade have scientists realized that this ice forms only in contact with a fungus—Exidiopsis effusa—which grows on dead wood. The fungus appears to release chemicals from the wood that cause the ice to form hair-like crystals instead of normal ice. I am not sure why other fungi do not produce similar results. In any event, Exidiopsis effusa occurs in the Pacific Northwest, the eastern United States, parts of Central America, Europe, and Asia. My sources for this tale include Sciencealert.com and iNaturalist.