Project 366 – Post No. 267 – Hoarfrost

What is Project 366? Read more here.

It was the first hunt of the year for the Snowy Owls of the Ray Gibbon Drive in St. Albert. It was a beautiful winter’s day with the sun beaming down from a clear blue sky and the temperature in the single digits below freezing point. As we were scanning the fields and wood lots at the outskirts of St. Albert I noticed that the stubble fields and the branches of trees and shrubs seemed whiter than usual and were glistening and sparkling as the rays of the sun hit them. A closer inspection revealed that they were covered in a delicate layer of ice crystals, ever so fragile and ephemeral. Only later did I learn that when ice crystals are formed on exposed objects, such as wires, branches or leaves it is called hoarfrost. The conditions under which hoarfrost is formed are rather specific. Hoarfrost ice crystals are formed on exposed objects by condensation of water vapor to ice at temperatures below freezing and occurs when air is brought to its frost point by cooling. Hoarfrost is formed by a process analogous to that by which dew is formed on similar objects, except that, in the case of dew, the saturation point of the air mass is above freezing. The occurrence of temperatures below 0° C is not enough to guarantee the formation of hoarfrost. Additionally, the air must be initially damp enough so that when cooled it reaches saturation, and any additional cooling will cause condensation to occur. In the end, we never found any Snowy Owls today, but the beautiful weather and the unique hoarfrost created a winter wonderland fitting for the coming holiday season.

May the curiosity be with you. This is from “The Birds are Calling” blog (www.thebirdsarecalling.com). Copyright Mario Pineda.