Blue Streak Week 10

I must say that this course has really made me much more aware of lighting, especially natural occurring phenomena. Once again, I was driving at dusk in the O.C. when I noticed the amazing multi-hued sky. The pinkish/orange from the horizon that develops into ambers then there is almost a lavender hue that melts into the vastness of the blue. What I find most intriguing with this picture is the sweeping blue line that is direct towards a steam cloud that is on the UCI campus. I am guessing the blue streak is from a jet. Below is a definition I found interesting because of its reference to the blue color and Kelvin temp.

Contrails

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. Cloud formation by a mixing process is similar to the cloud you see when you exhale and "see your breath". The figure below represents how saturation vapor pressure varies as a function of temperature. The blue line is the saturation vapor pressure for ice as a function of temperature (in degrees Kelvin).