Jets and Cirrus
/Our sky can put on quite a show. These show CONTRAILS (Condensation Trails) and clouds. In fact, a CONTRAIL is nothing more than a manmade cloud that formed with the assistance of nature. Jets exhaust a trail of water vapor that condenses in the cold air aloft. If the air is too dry the vapor does not become visible in the form of a cloud. If there is enough moisture in the air (even though the sky may be clear) it will condense forming CONTRAILS. Here we see a mixture of cirrus clouds and CONTRAILS. They change shape with time as they move through different weather regimes overhead such as changes in temperature and wind direction and speed.