Ringing Contrails
At high altitude, aircraft exhaust often produces elongated ribbons of ice crystals. It seems as if the contrails are still in the air - in fact, they are full of movement. They usually rotate in opposite directions to each other and sometimes break up into ring-like elements.
In spring 2020, contrails suddenly became a rare celestial phenomenon. Otherwise the sky was often literally full of them, because the aircraft tracks can persist for a very long time, depending on the meteorological conditions. Their conspicuous absence due to global travel restrictions makes us realize how familiar they have become - almost like natural clouds.
Anyone who is able to observe them might be all the more inclined to take a closer look. It turns out that the stripes often show interesting dynamics, including drastic structural changes and turbulence, behind which complex physical processes are hidden. At least initially, the lines are dead straight. This is a typical sign of their technical origin. Their originators fly on a fixed course at speeds of around 900 kilometers per hour, dragging the fog-like ribbons behind them…
