Why can you see jet streams?

Question

Does it have something to do with the temperature? Sometimes of the year you can see many more much clearer.

Answer 1

You cannot see jet streams "global air currents"...You can see "vapor trails" or "Contrails" from jets. The trails you see behind aircraft are a result of the engines heating the cold air as the aircraft move through the sky, these type dissipate quite rapidly.. The trails you see behind some aircraft that linger for any extended time
are the result of ( some say ) "chemical waste" that is added to the aircrafts fuel so as to burn off the chemicals in the upper atmosphere a sort of "hazardous material dumping ground".. It's good that you look to the skies, and wonder. Do some research on "Aircraft vapor trails/contrails, you may not like what you read.

Answer 2

Well in this day u will see alot more jet streams or as they are called chemtrails and contrails . the natural stream is contrail which happens at 30000 ft or above caused by vapors in the jets exhaust freezing the other chemtrails are a good ol goverment spraying grid patterns dailly of alumi-oxide benzonite and much more metalic metals which they claim is somehow helping the people down below u can look all these up both chem and con trails by typing either in ur search box hope this helps take care and take big breaths of unfresh air
Its a Fact!

Chemtrails cause Chronic Health Problems. And the problem is growing. Your symptoms and health problems are not in your head! Chemtrails is a very real cause of many health problems in America and around the world today.

It has been reported that this program gained its legality from US Code Title 50, Section 1520, which gives the Secretary of Defense authority to order testing "involving the use of a chemical agent or biological agent on a civilian population" for research purposes.
Chemtrails spraying started in 1999. To this date no one has a definitive answer as to why the spraying is going on, nor why people are developing all sorts of odd health problems and complaints following spraying

http://www.chembuster.us/Las%20Vegas%20Tribune.htm

Answer 3

The condensation trail left behind jet aircrafts are called contrails. Contrails form when hot humid air from jet exhaust mixes with environmental air of low vapor pressure and low temperature. The mixing is a result of turbulence generated by the engine exhaust.

Answer 4

I suppose you are referring to vapor trails left when a hot engine penetrates very cold air at high altitude. Heat combines with cold equals condensation, hence a little thin cloud is created behind the jet aircraft.

Answer 5

they are actualy called contrails. contrails are trails of condensed water vapor (same thing as a cloud) that form the increased moisture put out by engine exaust. Contrails only form at very high altitudes (usually above 8 km) where the air is extremely cold (less than -40 degrees C). contrails are basicaly cirrus clouds."

Answer 6

I have never seen a jetstream. The jetstream is just wind. By definition a wind of 50kts or more. What you are probably referring to are contrails. What others have explained about how they form are correct.

Answer 7

depends on how saturated the air is. and yes, the colder the better because it requires less moisture for the air to be saturated. any wind which is 60kts or more is defined as a jetstream. we try to fly in them if they provide a tailwind, i was in one yesterday, it was 120kts and provided us with an extra 25 percent of our groundspeed. if we are heading into them then we avoid otherwise it would take forever to get to our destination.

Answer 8

contrals r frozen warer drops from jet fuel burning...THE jet stream is high atmosphere wind blowing like a river or stream around the earth west to east

Answer 9

Because there are particles formed which deflect light.

Steam is a gas and is invisible.
The particles are either water in aerosol, or minute ice crystals.

http://en.wikipedia.org/wiki/Steam

Answer 10

they are just steam, so it has to do with the temperature yeah, you can probably see them more clearly when it's colder.