Here's a reed of some sort, with a glaze of clear rime on the side facing a creek. How did the clear ice get there, and what is the white ice on top of it?


The fact that the clear ice is just on the side facing the creek indicates that the ice came from droplets blown off the creek. To have the ice buildup just on the side means that the droplets must have frozen soon after landing, but slow enough to spread out and fill gaps.

So, the droplet must have been larger than typical cloud droplets, and the temperature must have been within a few degrees of freezing. Clearly, the flowing water must have been above freezing, so the droplets must have cooled to below zero while drifting through the air.


A closer shot shows that the outermost ice, the white ice, is hoarfrost. Only hoarfrost would show the flat crystalline facets. Definitive proof that that ice grew out of the vapor that was blowing by. You can also see some hoar on the other side of the reed.

--JN