They look like swirls that came straight off Van Gogh’s paint brush. However, what you see is actually an amazing phenomenon called the Kelvin-Helmholtz instability.
This intricate pattern emerges in clouds when two different layers of air in the atmosphere are moving at different speeds and have different densities. Where these two layers meet there is a sheer layer that becomes unstable by the discontinuity of speed. This causes a vortex and small wave-like patterns to break out, which builds to create these larger billows.
They were named after the 19th-century physicists Hermann von Helmholtz and Baron Kelvin. It’s a pattern you can see in many different areas of nature and astronomy, mostly in the oceans and clouds, but also on Jupiter’s Red Spot and the Sun’s corona.
Napisala: Maria Djerdjaj