Category: "Ice Science"

Smaller Hoar Growing on Larger Hoar

November 22nd, 2014
Cold air came down the interior, spilling through gaps in the Cascades, cooling the western side. In the Seattle area, we got our first frost on Nov. 11, but the days stayed cold. Areas in the shade never lost their hoar, so the hoar frost kept growing.… more »

It’s not a rainbow (it’s better)

August 12th, 2014
In summer, the sun reaches higher elevations, bringing the possibility of new atmospheric displays. I saw this one in mid-June. The top, upward arc is the more familiar and common 22-degree halo. But pay attention to the one on the bottom. Its colors… more »

Halo in the sky? Uh, I don't see no halo...

April 20th, 2014
After a few days of fine bright spring weather, the barometer falls and a south wind begins to blow. High clouds, fragile and feathery, rise out of the west, the sky gradually becomes milky white, made opalescent by veils of cirro-stratus. The sun seems… more »

The fun of shooting down your own theories

April 10th, 2014
Thomas H. Huxley once wrote the famous line: The great tragedy of Science: the slaying of a beautiful hypothesis by an ugly fact. Great man and a catchy phrase, but perhaps he was being a bit overdramatic. To me, the slaying of a “hypothesis” (i.e., pet… more »

Equinox frost I: Patterns on roof, hood, window, and mirror

March 24th, 2014
Morning on the spring equinox, the first day of spring, brought a few gifts from winter. I) Film-frost, accentuated with hoar-frost on the cars. See the white of the hoar, following a pattern set down by the thin layer of film-frost. The roof of one… more »

Video of growing ice spike

March 6th, 2014
Take about a cup of water, place in a glass flask, then plunge in liquid nitrogen. Watch. What happens in that video is that the water starts to freeze from the bottom and sides of the flask, and the ice also spreads across the top surface. When the… more »

The cup and the butterfly

February 25th, 2014
In early January, while visiting a cold, dry region, I saw this frost on a wooden fencepost. The pattern resembled a cluster of butterflies. In the shade, these "butterflies" were blue, reflecting the blue sky. In the sun, they were bright white: These… more »

Raindrops on ice

February 23rd, 2014
When water droplets land on ice, what happens? If the ice is at least several degrees below zero (celcius), the drops freeze quickly, and build up a whitish, bumpy surface. When the ice surface is heated to melting, the droplets vanish into the melt.… more »

Bending of branch and pond

February 11th, 2014
Bending bending bending                 The fir branches are bending                 They are waiting for more snow The famous Japanese poet Basho wrote a poem like the above, except it was about bamboo bending under the snow load. I was… more »

Hoar that grows down and out

February 9th, 2014
It had been a continued spell of cold days and nights, the ground snow-free, the air clear and dry. No film-frost on the cars in the morning, and no spikes of hoar frost sticking up on grass or post. The only signs of ice had been the frozen pond and… more »