NATURE NOTES- Let it snow, let it snow...

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IT’S cold and we have just had our first fall of snow this weekend – and another white Christmas would be nice.

We were out in the freshly fallen snow yesterday and of course the chat was around how can every snow flake be different? The short answer is they are not.

Despite what you may have heard some snowflakes are exactly the same shape and size as other snowflakes. Jon Nelson, a researcher with Ritsumeikan University in Japan, has studied snowflakes for fifteen years, and has some interesting insights into their delicate structures.

He points out that the old adage that ‘no two snowflakes are alike’ might be true for larger snowflakes, but it does not hold true for smaller, simpler crystals that fall before they’ve had a chance to fully develop into the familiarly evocative hexagonal flakes. Regardless, the shape of snow crystals are incredibly diverse, this is partly due to their sensitivity to even the smallest temperature change as they fall through the clouds. So, how do snowflakes form in the first place? Put simply, at the heart of every snowflake is a minute grain of dust that was once floating in a cloud. Water vapour from the atmosphere condenses on this dust grain forming a droplet that freezes instantly – simple eh what!

Here are some fascinating snowflake facts:

The world’s largest ever snowflake to date found was 38 centimetres wide and 20 centimetres thick. This snowflake occurred at Fort Keogh, Montana, USA on 28 January 1887. Snowflakes can be categorized into six main types, plate (flat), column, stars, dendrite (lacy, needle, and capped column. When it is extremely cold the snow is very fine and powdery and snowflakes become quite simple in design, usually needle or rod shaped. When the temperature is near to freezing point, snowflakes become much larger and a lot more complex in design, for example, a star).

Snowflakes aren’t always white. Years ago, when coal was used in factories and homes, snow was often gray. Why? Because the coal dust entered the air and was absorbed by the clouds. The average snowflake falls at a speed of 3.1 miles per hour. (5 kilometers) Billions of snowflakes fall during one short snowstorm.

The temperature and amount of water vapor determines the shape of snow crystals

A blizzard occurs when you can’t see for a quarter of a mile.

The winds are always 35 miles an hour or more. The storm must last at least three hours to be classed as a blizzard. If any of these conditions are less, it is only a snowstorm.

After capturing 5,000 snowflakes and finding no two identical, Wilson Bentley wanted the world to know just how unique snowflakes were. He wrote over 60 articles and books and was eventually dubbed The Snowflake Man. When he died in 1931, Bentley was the world’s snowflake expert. There is even a child’s book that’s been written about Bentley and his snowflake research. It’s called Snowflake Bentley.