Hoarfrost Flowers and Frozen Ripples

April 02, 2020

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Photographer: Jim Deutch 
Summary Authors: Jim Deutch; Jim Foster

The photo above shows numerous feathery formations, some over an inch (2.5 cm) in length, growing from a patch of ice and snow on the bank of Six Mile Creek in Ithaca New York. This is a type of hoarfrost. These frost crystals may from whenever it’s very cold and an ample source of water vapor is close by. Supercooled water droplets had come in contact with the ice patch and began to grow as more droplets accumulated. The temperature on this bitterly cold mid-winter morning had dropped to about -20 F (-29 C). Note the perfectly clear, solid ice (top left) that looks like flowing water.