What is this picture?
Frosting on a cake? Nope. Ice on a lake? Nope. This is a picture of clouds over the Atlantic Ocean, taken from the Space Shuttle Columbia on January 18, 2003.
Look at it closely. See the swirls? They're known as von Karman Vortices. They were named after Theodore von Karman, a well-known Hungarian born engineer and physicist who spent a lot of time studying aerodynamics. Sound boring?
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Von Karman vortices, spawned by Alexander Selkirk Island in the southern Pacific Ocean.
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Well, here's a really short list of the really cool things von Karman worked on – helicopter design, cantilevered airplane wings, supersonic flight (aircraft traveling faster than the speed of sound), and rocket research. He and his students pioneered the use of rockets in fighter jets to give them that burst of power they need to take off from aircraft carriers. He also helped found NASA's Jet Propulsion Lab, a world leader in robotic space exploration.
This is not boring stuff. In fact, it's all great leading edge technology. |
Anyway, back to von Karman Vortices. Here's how they form.
The air in our atmosphere is constantly moving. We call this wind. We can't actually see wind, but we can see its effect on the things around us, like when our umbrella gets blown over at the beach or when a tree gets blown down in a hurricane.
But wind isn't strong enough to blow the top of an island over. So when a large chunk of air blowing across the ocean runs into a really, really tall island, what does it do? It goes around it. This detour creates large spinning eddies of air, or vortices. The eddies line up behind the island in a long row. The water vapor in the air (which we call clouds) makes the long row of spinning eddies visible.
The best way to see von Karman Vortices is to hang out in space. You say that's not possible? Well, your right. One day we'll all be space travelers, but right now we're not. So we rely on astronauts and satellites to take pictures of the vortices for us.
So what's so exciting about von Karman Vortices? They help us understand what's happening on other planets like Jupiter, where a thick layer of clouds surrounds a giant ball of gas and liquid. Scientists have spent a lot of years studying Jupiter's swirling clouds. It's the only part they can see. |
Von Karman vortices, spawned by the 4,300 foot tall Guadalupe Island in the Pacific Ocean. This image was taken on August 20, 1999, by SeaWiFS, a Sea-viewing Wide Field-of-view Sensor on Geoeye's OrbView-2 satellite. Under the right conditions SeaWiFS can also view plankton blooms that display fluid motion in the marine environment.
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