What are the causes and effects of contrails in the upper Mississippi valley?

In summary: Thanks for asking!There is nothing remotely sinister about contrails, and yes, they consist of frozen water vapour from jet exhaust.
  • #1
Dr.D
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I live in the upper Mississippi valley, near the boundary intersection for the states of Wisconsin, Iowa, and Illinois. It is a very rare day that I cannot see several, sometimes many, very high altitude con trails in the sky. The usually progress roughly NE across my area, although this morning they were heading south.

Are these simply water condensed from the engine combustion processes, or is there some more sinister explanation? Any knowledgeable comments would be much appreciated.
 
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  • #2
Dr.D said:
I live in the upper Mississippi valley, near the boundary intersection for the states of Wisconsin, Iowa, and Illinois. It is a very rare day that I cannot see several, sometimes many, very high altitude con trails in the sky. The usually progress roughly NE across my area, although this morning they were heading south.

Are these simply water condensed from the engine combustion processes, or is there some more sinister explanation? Any knowledgeable comments would be much appreciated.
This wikipedia article does a pretty good job explaining how contrails are formed:

https://en.wikipedia.org/wiki/Contrail

:smile:
 
  • #3
There is nothing remotely sinister about contrails, and yes, they consist of frozen water vapour from jet exhaust.
If you closely watch a plane flying at altitude you will notice that the trail forms slightly behind the plane.
The gap is because it takes a while for the exhaust to cool down enough to freeze.
Sometimes there is no trail because the air is very dry, so the water vapour is assimilated into the air as a gas instead of crystallizing.
On rare occasions the ice crystals spawn the development of larger cloud systems,
so they are not always completely benign, but that can hardly be considered as sinister.
 
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  • #4
rootone said:
frozen water vapour from jet exhaust

From what I remember it is more complicated, and part of the explanation calls for combustion products containing small particles that act as nucleation centers.
 
  • #5
Dr.D said:
Are these simply water condensed from the engine combustion processes, or is there some more sinister explanation? Any knowledgeable comments would be much appreciated.

@berkeman ... you know where this was heading aye ?

Dr.D ... if you are indeed a doctor ??, you should know better than to entertain the belief in the crackpot garbage of government instigated mind control etc by use of chemical release in the contrails of jet aircraft

Dave
 
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  • #6
Dr.D said:
or is there some more sinister explanation?
Your main question has been answered. After some cleanup of some well-meaning posts, this thread closed.
 
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1. What are contrails?

Contrails, short for condensation trails, are long, thin, and white lines that form behind aircraft in the sky. They are made up of tiny water droplets or ice crystals that are created when hot exhaust gas from the aircraft mixes with the cold air in the atmosphere.

2. Are contrails harmful to the environment?

Contrails themselves are not harmful to the environment. However, they can contribute to the formation of cirrus clouds, which can have a minor impact on climate change. The overall impact of contrails on the environment is still being studied.

3. Do contrails affect the weather?

Contrails can affect local weather patterns by creating thin, high-altitude clouds that can reflect sunlight and potentially cool the Earth's surface. However, their overall impact on global weather patterns is still uncertain and requires further research.

4. How long do contrails last?

The lifespan of a contrail can vary depending on atmospheric conditions such as temperature, humidity, and wind. Some contrails may dissipate quickly, while others can persist for hours and spread out to form cirrus clouds.

5. Can contrails be predicted?

Contrails can be predicted to some extent by using meteorological data to determine the likelihood of contrail formation based on temperature, humidity, and atmospheric conditions. However, predicting their exact location and persistence is still a challenge for scientists.

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