Template:POTD/2023-08-11
A Kármán vortex street is a process in fluid dynamics in which a repeating pattern of swirling vortices, caused by vortex shedding, is responsible for the unsteady flow separation of a fluid around blunt bodies. It is named after the Hungarian-American engineer and fluid dynamicist Theodore von Kármán. This satellite image, taken by NASA's Landsat 7 in 1999, shows a Kármán vortex street caused by wind flowing around the Juan Fernández Islands off the Chilean coast in the South Pacific Ocean. The flow of atmospheric air over obstacles such as islands can cause visible vortex streets when a cloud layer is present at a certain altitude. It can reach a length of more than 400 kilometres (250 miles) from the obstacle in such cases, with a typical vortex diameter of 20 to 40 km (12 to 25 mi).Photograph credit: Robert Cahalan, NASA