We Flew By Contrails!
Wow!!! I was just looking outside the airplane window and and there in the sky were contrails from another plane that must have flown by recently. It looked very cool and I had never seen any from the air before. I hope the pictures came out okay! Yes, I know it doesn’t take much to excite me 
Contrails are the cloudy streaks that an airplane sometimes leaves behind in the sky, right? That’s what I saw, even if I got the name wrong.On a side note – I need a good dictionary for my MacBook that doesn’t need me to be on-line to use it. Just a big PDF would work fine. Anyone know of anything semi-recent in the public domain or something? Or if I can purchase one somewhere? Something old enough to have copyright expired probably would not have “contrails” in it…
Contrails, which develop when water vapor released in aircraft exhaust fumes spontaneously turns to ice, can form at altitudes and humidities that do not support normal clouds.
From ‘Scientific American’ September 2002
From the article – Climatologists think that contrails exert a net warming influence, perhaps as large as 2 percent of the global warming resulting from greenhouse gases. The three-day grounding of commercial aircraft last year (9/11) has provided some insights on contrails effects. He saw an increase in the daily swing of high and low temperatures of 1 degree Celsius, suggesting that contrails dampen the diurnal temperature range.