Theodore von Kármán (1881-1963), a Hungarian-American physicist, was the first to describe the physical processes that create long chains of spiral eddies like the ones shown above. Known as von Kármán vortices, the patterns can form nearly anywhere that fluid flow is disturbed by an object. In this case, the unique flow occurs as winds rush past the tall peaks on the volcanic islands. As winds are diverted around these high areas, the disturbance in the flow propagates downstream in the form of vortices that alternate their direction of rotation.
Satellite sensors have spotted von Kármán vortices around the globe before, including off of Guadalupe Island, near the coast of Chile, in the Greenland Sea, in the Arctic, and even next to a tropical storm. The scene above is particularly notable for the fact that three distinct streams of vortices are visible.
von Karman vortices form nearly everywhere that fluid flow is disturbed by an object. In the cloud images shown on this page, the “object” that is disturbing the fluid flow is an island or group of islands. As a prevailing wind encounters the island, the disturbance in the flow propagates downstream of the island in the form of a double row of vortices which alternate their direction of rotation. The animation below (courtesy of Cesareo de la Rosa Siqueira at the University of Sao Paulo, Brazil) shows how a von Karman vortex street develops behind a cylinder moving through a fluid.
In the image below, an isolated Norwegian territory in the North Atlantic Ocean, called Jan Mayen Island, is responsible for the spiraling cloud pattern. The unique flow occurs when winds rushing from the north encounter Beerenberg Volcano, a snow-covered peak on the eastern end of the island that rises 2.2 kilometers (1.4 miles) above the sea surface. As winds pass around the volcano, the disturbance in the flow propagates downstream in the form of a double row of vortices that alternate their direction of rotation.
Bottom line: Satellite images of von Kármán vortices
Eleanor Imster has helped write and edit EarthSky since 1995. She was an integral part of the award-winning EarthSky radio series almost since it began until it ended in 2013. Today, as Lead Editor at EarthSky.org, she helps present the science and nature stories and photos you enjoy. She also serves as one of the voices of EarthSky on social media platforms including Facebook, Twitter and G+. She and her husband live in Tennessee and have two grown sons.