Image of the Week: Spinning Cloud Spirals


This beautiful image shows a flying Boeing 777 and the effect of its wing tip vortex on the clouds behind it. Wingtip vortices occur because of the difference in pressure between the upper and lower surfaces of a wing. The higher-pressure air flowing along the lower surface tries to go around the wingtip to the upper surface and, as a result, a vortex is created. They trail back from each wingtip and have a tendency to sink and roll toward each other downstream of the aircraft. Eventually, the vortices dissipate, their energy being transformed by viscosity.

An airplane flying into another airplane’s vortex faces the possible risk of rolling over and the pilot may lose control. This is especially dangerous in the region behind an airplane in the takeoff and landing phases of flight, and the effects of vortices have become a major problem to the air traffic controller in the terminal area. This is why many airplanes are now equipped with winglets – the tabs at the end of the wing that separate the two airflows, creating a barrier and preventing a vortex from forming.

Wingtip vortices are normally invisible, but when a big aircraft like this “Triple Seven” passes through thin clouds, we may see its trail forming poetic foggy spinning spirals as amazing as the one in the picture.


Miquel Sureda is studying for an MSc in Science Communication


Leave a Reply

Your email address will not be published. Required fields are marked *