Contrails crossing over Houston

On almost any sunny day, you can look up and see contrails crossing the sky.  These "condensation trails" are produced by jets flying across the country. When hot, humid air in the jet exhaust mixes with the cooler air temperatures aloft, the moisture condenses and creates an artificial "cloud."

The length of a contrail and the amount of time it takes to dissipate depends on the weather conditions aloft. If the atmosphere at flight level is humid, the contrail will last for hours; if it's dry, the contrail will dissipate more quickly. Also, since the temperature, humidity and wind vary greatly throughout the atmosphere, contrails can be dashed, jagged, wavy, short, long, fat and skinny. And depending on the direction planes are flying when they pass over Houston, the contrails can sometimes create interesting patterns in the sky, like the "X" you see in the TowerCam snapshot above.

Over the years these patterns have captured the attention of some folks who believe the white streaks are not contrails, but rather chemtrails. Conspiracy theorists believe our government is spraying chemicals, viruses and cancer into the air. Once such believer called the ABC13 weather center last week when the "X" pattern seen above showed up over Houston.

Giving the caller the benefit of the doubt, I immediately checked the flight paths over Houston. The image to the right is from FlightAware and was captured at the same time as the TowerCam snapshot above. The map shows the position of every passenger plane in the air. If you look carefully, you'll see several paths crossing each other in an "X" pattern. (Contrails can be much longer than the lines shown on the map which only indicate position reports received from the planes.)

There could be a real concern about contrails, however it has nothing to do with our government trying to kill us. The man-made cirrus clouds could block sunlight during the day and hold in the heat at night. As air traffic increases in the future, more studies will need to be done to determine if contrails cause a general cooling or warming of the atmosphere.

As always, you can post your comments below.

Comments

[mikemcguff]

At first I thought this post was going very Art Bell/George Noory.

[Amanda]

I'm going to send this page to my hubby, though I doubt it will faze him. He's a chemtrail guy, I'm a contrail girl. It never ends, lol.

[Dean Riley]

You are right about the debate about the affects of contrails on the earth's overall climate. This made me recall a particular study which was (sadly) done during the week of 9/11 when the planes were grounded for three days. Climatologists had an unprecedented chance to study this. This kind of study seems very difficult to do.

Dean Riley

[Cole]

Thanks, Tim, for the always insightful info. My mom is a retired Captain from Continental, and she's always pointed out to me the interesting patterns that contrails can make in the sky. I've never heard of the "chemtrail" theory, but it's always good to know what other people think, I guess.

[Raj C.]

I'm definitely a "contrail" guy. It took our government a week to respond to a storm they knew was coming. Yet, people feel that Uncle keep crazy complicated secrets. Not buying it.