Posted on 03/29/2011 9:40:47 PM PDT by NormsRevenge
The long, feathery lines of condensation that form behind aircraft, called contrails, have more of an immediate warming effect on the Earth's surface than the carbon dioxide or other greenhouse gases that the aircraft emit, a new study calculates.
However, the researchers add, contrail clouds disappear within a day or two; the potent greenhouse gas carbon dioxide lingers in the air for many years.
Contrails form when the hot, moist plume of exhaust generated by an airplane's engines mixes with cold air in the upper atmosphere. Liquid droplets form and then freeze, forming a straight, white line. Over the span of a few hours or more, the contrail loses its definition and becomes a wispy cirrus cloud. But if the atmosphere is very moist, the line shape can exist for days, said Ulrike Burkhardt, a researcher at the Institute for Atmospheric Physics ..
If there were no other clouds in the sky, contrail cirrus clouds would cover up to 10 percent of European skies and about 6 percent over the east coast of North America, another heavily trafficked region, they calculated. They disappeared from American skies briefly when nearly all airtraffic was grounded after the 9-11 attack. Some research has indicated that this resulted in more variation in temperatures, particularly warmer daytime temperatures.
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Contrail clouds have another complex effect: They use up water vapor that normally could go into the formation of natural cirrus clouds, according to Kärcher and Burkhardt.
When all of these effects are considered, contrail clouds ultimately alter the Earth's energy budget in a way that warms it, by reducing the amount of energy that escapes back out into space, the team found. Greenhouse gases do the same thing, trapping energy that would otherwise escape into space and so warming the planet.
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(Excerpt) Read more at livescience.com ...
Ever notice it is only the sky above the head of the idiot making such a claim as the 911 deal? Whether a jet leaves a contrail has more to do with the amount of moisture in the air than anything else, but when there is no flying at all, such a brilliant mind. If any reasoned researcher would notice, especially on very dry and cold days, a jet may leave a small contrail behind it. Often when one really looks at it, a long contrail is usually broken for spans with no contrail because of the pockets of dry air it is flying through.
If they really want an education on how non-homogeneous our atmosphere really is at low levels, have a hot air balloonist explain it to you.
Or maybe a retake on the old Johnny Cash song, “How high is the water Ma” -
How high is the b.s. Ma? Knee high and rising.
More Junk Science foisted by fools with advanced degrees.
It is true that the vapors prevent loss of ground heat into space by reflecting the heat back to the ground, but it is also true that it will have no real effect on the climate. It’s a lot like pouring water on the sidewalk during a rain storm. The sidewalk isn’t any wetter either way.
Global warming causes cooling. Duh.
/s
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