Sometimes, snow or ice may appear to be blue. The blue light is the product of a long path through the snow or ice. Think of snow or ice as a filter. A filter is designed to reject some substances, while permitting others to pass through. In the case of snow, light makes it through if the snow is only a centimeter thick. If it is a meter or more thick, however, blue light often can be seen.
Snow falls in the Earth’s extreme North and South throughout the year. However, the heaviest snowfalls have been reported in the mountains of other areas during winter. These areas include the Alps in Italy and Switzerland, the coastal mountains of western Canada, and the Sierra Nevada and Rocky Mountains in the United States. Snow is even known to fall near the Equator, but only on the highest mountains.
Each year, the continental United States has an average of 105 snowstorms. An average storm produces snow for two to five days.
Almost every part of the United States has received snowfall at one time or another. Even parts of southern Florida have reported a few snowflakes.
The national record for snowfall in a single season was set in the winter of 1998 to 1999. Two thousand eight hundred ninety-five centimeters of snow fell at the Mount Baker Ski area in the northwestern state of Washington.
People in many areas have little or no natural snowfall, but they still want to see snow. So scientists have come up with a solution. In 1936, a physicist from Japan produced the first man-made snow in a laboratory. Then, during the 1940s, American scientists developed methods for making snow in other areas. Clouds with extremely cool water are mixed with man-made ice crystals, such as silver iodide and metaldehyde crystals. Sometimes, dry ice particles or liquid propane are used. Today, machines are used to produce limited amounts of snow for ski areas when not enough natural snow has fallen.
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2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25