The Magic of Ice
From the ordinary to wild and downright wacky. The variety of ice we encounter in nature depends on the conditions that created it.
Two forms of ice, hoar frost, and rime ice, excite photographers the most because of their photogenic nature.
Hoar Frost
We’re all familiar with dew. When supersaturated moist air near the surface of the ground is cooled to its dew point, tiny droplets of water condense on surfaces.
Hoar frost is formed by a similar process. But with hoar frost, the supersaturated moisture in the air skips the liquid droplet stage and goes straight to ice when temperatures are below freezing. Hoar frost also needs calm air that allows those complex lacy deposits of crystals to form.
The name derives from the old English word “hoary,” meaning getting on in age. Many trees, especially evergreens, take on a "hair-like" appearance resembling a white, feathery beard. These deposits are quite fragile.
An example of hoar frost crystals on the icy Dietrich River in Alaska.
Rime Ice
Rime ice can also coat nature in magical ways. When supercooled (below 32°F) fog droplets instantly freeze and attach to exposed surfaces below 32°F, you get rime ice.
Soft rime ice forms under calm wind conditions. The fog usually freezes to the windward side of solid objects, particularly tree branches and wires. It is similar in appearance to hoar frost with narrow white icy needles and scales. Soft rime is quite fragile.
Hard rime ice is denser and more difficult to remove. It’s often seen on trees atop mountains and ridges in winter, when low-hanging clouds cause freezing fog. The fog freezes to the windward side of tree branches, buildings, or any other solid objects, usually with high wind velocities and air temperatures between 28 and 18 °F.
The Shot
We arose on the morning of February 18 and drove the Dalton Highway to an area near Livengood, Alaska looking for a group of hard rime ice-encased trees. We arrived too early and waited in the van where it was warm.
The two trucks that went by both stopped to check on us as we might have been a disabled vehicle. It was a good feeling to know that people cared about our welfare in that remote stretch of Alaska.
As dawn approached, we wandered through the knee-deep snow looking for compositions. This composition was framed on top by a bowed-over tree and an upright tree. Inside the frame were three rime-encased trees and clouds to the east.
Normally, sunrise shooting is a frantic race against time. You typically have mere minutes to capture the warm colors of dawn. But near the Arctic Circle, we had close to an hour of good light! After two hours of photography, we headed back to the van for the long drive south to Sutton, Alaska.
Thanks for looking,
Chuck Derus