Category: "Snow Science"

Two-level nature of branched crystals

December 11th, 2016
The common branched crystal looks like a paper cut-out, but actually has a complex 3-D nature. One aspect of this nature, which I have alluded to in prior posts, is the two-level structure: What appears to be happening on one plane, is actually… more »

How some snow crystals hide their droplet origin

December 5th, 2016
Look closely at the center of a snow crystal. In many, or most, you will often not find a droplet center as we described in the previous post. Indeed, for the columnar crystals, you may never see a droplet center. As an example, look at the center of… more »

How the water molecules make corner pockets

November 11th, 2016
As I mentioned in my previous post, the formation of corner pockets on ice crystals is inexplicable by the standard theory of snow-crystal growth. Akira Yamashita had recently proposed a mechanism for corner pockets, though he had applied it to a… more »

Akira's Corner Pockets

May 10th, 2016
The evanescent snow crystal appears out of nowhere The lines and boundaries on its faces tell a story a story of its birth and life But before it all vanishes does anyone hear the story?   A few years back, a correspondent of mine, Professor Akira… more »

A Change in Habit

November 23rd, 2014
The two main growth modes of snow and hoar (i.e., ice growth from the vapor) are columnar and tabular. In columnar, the shape is long and thin, like a pencil or cluster of pencils (bound snugly with a rubber band). In tabular, the shape is plate-like or… more »

New habit diagram for branched tabular crystals

August 24th, 2014
You might call these “snowflakes”. But let's be specific here with the names. Anyway, a close associate who has been sweating over his snow-crystal growth machine in Japan for many years has just published his latest results. His machine is a vertical… more »

The new ice-crystal-growth apparatus

July 1st, 2014
After a few years in the making, our new device for growing single ice crystals in a well-controlled laboratory environment is nearly ready. We are just adding a few small accessory pieces to allow us to start testing. I was to describe the apparatus at… 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 »

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 »