The conspiracy theorists know how to spoil a nice day. Every time a gorgeous display of jet contrails graces our sky, certain people will pop up and claim that the U.S. government is spraying us with chemicals. The contrails, a contraction for "condensation trails", suddenly become chemtrails.
I'm all for freedom of belief. Everybody is entitled to their own opinions in life. But the chemical thing is wrong. These are simply jet aircraft depositing water vapor as part of the exhaust from their engines. When the water vapor comes in contact with air that is well below freezing, as it is at 25,000 feet and higher even in the middle of summer, the vapor immediately turns to ice crystals. These ice crystals will sometimes form a long string of man-made cirrus clouds.

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Some days there are no contrails even with commercial jet aircraft flying high overhead. Other days the contrails are long-lasting and spread out to form a layer of cirrus clouds. Why the difference? Some people have claimed that the government only sprays us with chemicals on certain days. This is not true. The reason is far less sinister.
The appearance of contrails depends upon the moisture content of the air at the altitude of the aircraft. If the air is very dry aloft, aircraft will leave either no contrail or a very short one. That's because any moisture expelled by the jet engines evaporates immediately, so any ice crystal that forms won't last long. If the atmosphere at the altitude of the aircraft is more moisture-laden, the water vapor-turned-ice crystal will remain for a long period of time. Winds aloft will help spread out the contrail.
In areas where commercial jet traffic is high, many contrails will criss-cross the sky and form cirrus clouds.
Professor David Travis at UW-Whitewater has done some interesting research on the effect of contrails on climate. He used the days following September 11, 2001, as part of his control set of data. This was a period, you may recall, when all commercial air travel was suspended and there were no contrails anywhere across the United States. It's a fascinating look at how sensitive our climate can be to certain changes. Check out an on-line article about the study at THIS LINK.
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aaro-nf
May 8, 2008 | 5:03 PM |
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swilson45
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Vince_Condella
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johnnythefox
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F0x6Fan
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Chemtrails-r-real
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Chemtrails-r-real
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chemtrails
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speakoutnow
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Chemtrails-r-real
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skywitness
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skywitness
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skinnymarie
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collinsbac
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collinsbac
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lodo_4
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KittyDAC
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whatfuture
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Chemtrails-r-real
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Chemtrails-r-real
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FOX 6 Chief Meteorologist Husband, Dog Owner, Bicyclist, Motorcyclist, Guitar Player, Yoga Devotee, student of Buddhism
Member Since: 8/24/2006