Snowfall helps to protect plants and some wild animals from winter weather. Fresh snow is made largely of air trapped among the snow crystals. Because the air has trouble moving, the movement of heat is limited.
Snow also influences the movement of sound waves. When there is fresh snow on the ground, the surface of the snow takes in, or absorbs, sound waves. However, snow can become hard and flat as it grows older or if there have been strong winds. Then, the snow’s surface will help to send back sound waves. Under these conditions, sounds may seem clearer and may travel farther.
BOB DOUGHTY: Generally, snow and ice appear white. This is because the light we see from the sun is white. Most natural materials take in some sunlight. This gives them their color. However, when light travels from air to snow, some light is sent back, or reflected. Snow crystals have many surfaces to reflect sunlight. Yet the snow does take in a little sunlight. It is
this
light that gives snow its white appearance.
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.
(MUSIC)
FAITH LAPIDUS: 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.
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2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25