Rare sighting of sinusoidal thin contrails

Rare sighting of sinusoidal thin contrails

Thu, 07/04/2016 - 08:24
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Photo: The sighting came from Tofino on the west of Vancouver Island, Canada 
CreditTofino Photography

The Royal Meteorological Soceity received these photographs this week, sent in from Tofino, on the west of Vancouver Island in British Columbia, Canada, asking for an explanation of how they are formed. 

The most likely explanation for what we’ve seen is that this was a hybrid contrail that’s then taken the shape of sinusoidal thin clouds and has been caused by exhaust contrails in the wing tip vortices, which are circular patterns of rotating air left behind a wing as it generates lift. 

When you do see these clouds, they are usually observed behind large planes that create stronger wake vortices, such as Boeing 747’s, with the amount of time these contrails able to last limited by the Crow instability. The photos sent in are of solitary hybrid contrails, and these can persist for longer in the atmosphere compared to hybrid contrail pairs, which means there was some form of atmospheric turbulence.