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Science
How does the wind blow?
By Cynthia Kirkeby, John Leask Lumley (CCMR)
Sep 13, 2006, 14:11

How does the wind blow?

Glenna Murray age 6
First grade




Glenna-

According to John Leask Lumley, a scientist at Cornell (CCMR), “The sun's light heats the surface of the earth... It does not heat it uniformly .... Water and soil and rock absorb the heat differently.

The heated surface heats the air... the ... air gets bigger, fills more space and tries to rise, because [it] ... now weighs less. If the air rises here when the sun is heating the surface, air has to come here from somewhere else (where the sun is not heating the surface) to replace it. This is a wind.

Every day when the sun rises and sets, you can feel this kind of wind. The edge of the line between day and night is passing where you live - the day side is being heated, and the night side is not, and a wind will blow from night to day across the line.

There are other winds like this. When the sun shines on water and land, the water does not get as hot as the land. If the sun shines on a lake shore, there will be a wind from the lake to the land, because the air over the land is rising. Winds like this, and the one from night to day, are small scale - they take place in a space a few hundred miles on a side.”

To read more of his explanation on wind, please visit their site: http://www.ccmr.cornell.edu/education/ask/index.html?quid=194

Cynthia Kirkeby
ASK ClassBrain



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