SNOW
Snow is a beautiful thing. It is precipitation in the form of small white ice crystals. Snow is formed from the water vapor in the air at a temperature of less than 32 degrees Fahrenheit.
How do Snowflakes Form? It turns out that "pure" snow is made up of snowflakes which are made up of from 2 to 200 separate snow crystals. Snow crystals are crystals that have formed around tiny bits of dirt that have been carried up into the atmosphere by the wind.
Scientists think that there are really four different shapes of snow crystals. The simplest shape is a long needle shaped like a spike. The other shapes all have six sides. One of them is a long, hollow column that is shaped like a six-sided prism. There are also thin, flat six-sided plates. And lastly there are intricate, six-pointed stars. The shape that a snow crystal will take is dependent upon the temperature at which it was formed. The temperature in the highest clouds is around -30°F and they are made up exclusively of ice crystal columns. The other three shapes are formed in a narrow temperature range. When the temperature in the clouds is 3° to 10°F the star shaped crystals form. From 10°-18°F the plates form, and from 18°-23°F columns form. From 23°-27°F needles form and from 27°-32°F the plates reappear. Each snowflake is made up of from 2 to about 200 separate crystals.
All precipitation (rain and snow) comes from water vapor in the air. If the air is warm, the frozen droplets melt and fall to the earth as rain. If the air is cold, however, the water vapor crystallizes around a speck of ice or dust and falls to the earth as snow. If there is no dust for the water vapor to crystallize on, it will remain in the air as a cloud, even if it gets as cold as -40 degrees Celsius(-40oF)!
Why is snow white? Snow crystals reflect the full spectrum of light, which we see as white. However, some snow is red, green, blue, or black. This occurs because of beautifully colored fungi that are rarely found in snow.
Did you know that freshly fallen snow is much lighter than water? The reason is that there is a lot of air between the flakes! In very dry areas, 1 centimeter of water will produce 20 centimeters of snow. In very moist areas, 6 centimeters of snow will melt down to only 1 centimeter of water. Because it is compressed, older snow has less air between flakes and contains much more water. Glaciers are formed from the compression of snow over many years.
The Eskimos, or Inuits, who live in the north, have developed many words in their language to describe the different types of snow. Some of these are:
Anniu ª falling snow
Api ª ground snow
Siqoq ª smoky, drifting snow
Upsik ª wind-beaten snow
Kimoaqtruk ª snow drift
Salumaroaq ª smooth snowy surface of fine particles
Natatgonaq ª rough snowy surface of large particles
Which country gets the most snow every year? The US. for example, is less snowy than Canada, on average -- by a lot. But there are places in the U.S. that receive more snow than most places in Canada. The U.S. has a long history of measuring "inches of snowfall" while that has not been a standard meteorological measurement in many other countries.
There are snowy places in high mountains in other parts of the world (Asia, for example) but snowfall generally falls short of those areas that are closer to relatively warm oceans. So some of the possibilities become the U.S. Pacific NW, British Columbia in Canada. The areas of SE Alaska where mountain ranges are close to the Pacific. Then head over to Europe -- the Alps harvest a lot of Atlantic and Mediterranean Sea moisture. The mountains of Norway get tons of snow. In the southern Hemisphere there are fewer candidates, but the best is the southern Andes mountains, and the mountain ranges of New Zealand.
The type of snow that skiers like best is called powder snow. This type of snow is good for most snow sports. Powder snow is usually dry or slightly moist. Its density has to be less than 200 kilograms for every meter of snow. The density of something indicates how much it is compacted. Snow that is more densely packed makes better snowballs.
Written by Enje taken from any sources.
Written by Enje taken from any sources.
No comments:
Post a Comment