Sandy streets over the Atlantic

Feb 10, 2012 by Jason Major, Universe Today
Dust from the Sahara blows past the Cape Verde islands on Feb. 9, 2012. Credit: EOSnap/Chelys SRRS (Satellite Rapid Response System

Thick dust from the Sahara blowing over the ocean off the western coast of Africa encounters the islands of Cape Verde, forming a wake of swirling “vortex streets” visible by satellite.

These swirls are also known as von Karman vortices. When wind encounters the island, the disturbance in the flow propagates downwind in the form of a double row of vortices, which alternate their direction of rotation.

Such effects can be seen anywhere a liquid — including air — flows around a solid body. They are named after engineer and fluid dynamicist Theodore von Kármán.

In the image above, the dust and sand is thick enough to nearly block out some of the islands entirely. See the full scale version here on the Chelys “EOSnap” Earth Snapshot site.

Explore further: Scientists may be cracking mystery of big 1872 earthquake

add to favorites email to friend print save as pdf

Related Stories

Cloud streets off of the Aleutian Islands

Jan 30, 2012

(PhysOrg.com) -- Strong winds polished the snow of southwestern Alaska and stretched marine stratocumulus clouds into long, parallel streets in early January, 2012. After crossing Bristol Bay, the winds scraped ...

Earth from space: Dust and plankton

Apr 15, 2011

(PhysOrg.com) -- Envisat captures dust and sand from the Algerian Sahara Desert, located in northern Africa, blowing west across the Atlantic Ocean last week.

The pirouette effect in the chaos of turbulence

Jun 09, 2011

(PhysOrg.com) -- The quick mixing of coffee and milk after stirring or the formation of raindrops in clouds: these are just two of many phenomena in which turbulent flows play a decisive role. Researchers ...

Eddies in Einstein's formula

Oct 07, 2011

(PhysOrg.com) -- How does a microscopic particle behave in a liquid? New results published in the journal Nature show that Einstein’s formula for describing this situation needs a little adjustment. This w ...

Recommended for you

Bridgmanite: World's most abundant mineral finally named

29 minutes ago

A team of geologists in the U.S. has finally found an analyzable sample of the most abundant mineral in the world allowing them to give it a name: bridgmanite. In their paper published in the journal Science, the te ...

Volcano in south Japan erupts, disrupting flights

7 hours ago

A volcano in southern Japan is blasting out chunks of magma in the first such eruption in 22 years, causing flight cancellations and prompting warnings to stay away from its crater.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.