1) Ice fog 
dense fog of suspended ice particles
A term of Native American origin used for ice fogs occurring in mountain valleys of the western United States.
pogonip 1. Dense fog of suspended ice particles; an Indian word for the formation of frost on trees but not on the ground; etymology, Shoshone pakenappeh (or some other American Indian language) which means 'white death'. 2. Pogonip, or 'ice fog', results in a phenomenon called 'hoarfrost', which is a deposit of interlocking ice crystals on object...