Yale Environment 360: Jet contrails can mimic the weather impact of clouds and significantly affect daytime and nighttime air temperature swings by up to 6 degrees Fahrenheit in some locales researchers from Penn State have shown. Data from the three days following September 11, 2001, when air travel was highly restricted, had shown that jet contrails thin clouds composed of ice crystals condensed from an aircraft's exhaust likely had an effect on air temperatures. To study the issue over a longer time period,...