Persistent Spreading Contrails - Clouds Protocol

Persistent Spreading Contrail

Here is a persistent spreading contrail with a demonstration of the technique used to identify them. This contrail is about four fingers wide - just about enough to be picked up in current satellite imagery. Identification as a contrail - as opposed to natural cirrus - is made from the linear appearance, as well as the "loopy" internal structure. In contrast, the natural cirrus to the lower right of the photo has a much more wispy appearance - like a paintbrush across the sky. Photo by Lin Chambers, Virginia.

Persistent Spreading Contrail

This is a narrower persistent spreading contrail, which is closer to the index finger width. Note the regular "loopy" appearance of the edge of the contrail, reflecting the swirling air motions that are set up behind the airplane. Photo by Carol Clark, Oregon.

Multiple Persistent Spreading Contrails

This is a fairly common sight on the East Coast, where lots and lots of airplanes fly between the major cities of the Eastern Seaboard. However this photo captures a wonderful display of these contrails, showing them at various stages of "spreading". Photo by Ralph McConnell in Hertford, NC, looking toward the northeast. Submitted by Aileen Seshun.

View from the Air

On the same day and in the same area as above, here is a view from the air. This is taken on a southbound flight over North Carolina at 9:45 am on Feb. 20, 2004. From this perspective, one can see the large number of contrails from the morning's air traffic being carried slowly eastward over the Atlantic Ocean by the prevailing winds. Photo by Dr. Paul Filmer,

Criss-crossing contrails

This photo shows a series of contrails creating a cross-hatch pattern across the sky. It was taken in near the town of Chartres, France. This is not too far from Paris. This interesting pattern is likely a result flights from the UK to Europe on the one hand; and within continental Europe on the other. Thanks to Didier for contributing this photo.

Contrail over Hawaii

This photo collage shows a major persistent spreading contrail over the Mauna Loa observatory in the Hawaiian Islands. It was put together by Forrest Mims, who regularly visits the observatory for instrument work. Neither he nor resident scientists at the observatory could remember seeing such a contrail in this area before. Photos May 2005