reply to post by Sherlock2009
You say you "know" what condensation trails look like. Well, sometimes those trails look and behave differently form other times. It all depends
on the water vapor saturation levels are, at any specific altitude. And, the temperature of course. It is the
combination of factors.
These planes were at about 30,000ft. Leaving trails that stayed for hours and turned into haze.
They didn't "turn into" haze. What will happen, when the above mentioned conditions are suitable, is the presence of the contrails will trigger
more of the surrounding air to condense out, into more ice crystals, forming very thin layers of more cirrus clouds. It is the way the
clouds will also develop naturally -- the airplanes' passage and leaving of contrails contributes to the tipping point, and gives Nature a
kick-start.
It is THAT simple!! Study up on meteorology courses at the local Uni, or hit the library and find books on the topic
Strange thing is that other planes at the same altitude didnt leave any!
This is raised so often.....can you tell the difference in their altitude, with the naked eye, from the ground? If some jets are at 30,000 feet
exactly, and some others are at 34,000? Or, 33,000? Even one thousand feet of change can be the difference between contrails, and no contrails.