I was pretty sure that this this fallen branch of a tree was covered in Hoar Frost, but being the inquisitive type that I am, I did a bit of checking. Yup – Hoar Frost.
Hoar Frost – Fanny Bay
Hoar frost (or radiation frost) is white ice crystals, loosely deposited on the ground or exposed objects. The frost forms on cold clear nights when heat is lost into the open sky causing objects to become colder than the surrounding air.
Hoar frost can develop in several forms.
- Air hoar is a deposit of frost on objects above the surface, such as tree branches, plant stems, or wires.
- Surface hoar is fernlike ice crystals directly deposited on snow, ice or already frozen surfaces.
- Crevasse hoar is crystals formed in glacial crevasses where water vapour accumulates under calm weather conditions.
- Depth hoar is cup shaped, faceted crystals formed beneath the surface of dry snow.
And now you know…