Image: Contrails left by jet aircraft in the sky

Caption: An infrared AVHRR (Advanced Very High Resolution Radiometer) satellite image from a NOAA polar orbiting satellite.  The image shows a dense cluster of jet condensation trails (contrails) occurring over the southern California coastal region.  Contrails can be distinguished from natural clouds by their linear appearance and tendency to occur in random directions with no association with the synoptic weather flow.

When all commercial aircraft were grounded after September 11, 2001, a unique portal opened onto surface temperature. The range in daily temperature on those days without jet flights proved to be the widest in 30 years. The reason: Contrails block sunlight by day and help the earth retain heat by night.

Source: Contrails, Cloud Cover, and Temperature, David J. Travis, University of Wisconsin-Whitewater.

NSF Funded: yes

Previous slide Next slide Back to first slide View graphic version