July 4th, 2002: Description: As air flows over and around objects in its path, spiraling eddies, known as Von Karman vortices, may form. The vortices in this image were created when prevailing winds sweeping east across the northern Pacific Ocean encountered Alaska’s Aleutian Islands. Source: Landsat 7 To learn more about the Landsat satellite go to: <a href="http://landsat.gsfc.nasa.gov/" rel="nofollow">landsat.gsfc.nasa.gov/</a>

Canary Island Group and von Karman Cloud Vortices.

STS040-75-003 (5-14 June 1991) --- This image shows several of the Canary Islands, located in the North Atlantic Ocean just west of Africa. Low level stratus clouds often form here (and along the west coast of continents at these latitudes) are trapped in vertical movement due to an overlying atmospheric temperature inversion. The islands are generating disturbances in the low-level wind flow which is generally from the north-northeast or from top to bottom in the image. These disturbances travel downstream from the islands and manifest themselves as cloud swirls which are called von Karman vortices. The northern extent of a large dust storm moving off the coast of Africa is apparent at the lower right of the image. The dust, extended across the Atlantic Ocean as far west as the Dominican Republic later in the mission.

Earth observation image of Von Karman Vortices taken during STS-100

STS100-710-182 (19 April-1 May 2001) --- Easily recognizable in this STS-100 70mm frame are phenomena known as the von Karman vortices, which were forming in the stratocumulus field downwind from the volcanic island of Rishiri-to in the northern Sea of Japan off the northwest coast of Hokkaido, Japan. According to NASA scientists studying the STS-100 photo collection, these features form when a stable atmosphere with low clouds flows past a relatively small obstacle with a height greater than the depth of the cloud layer. Because the atmosphere is stable, a series of eddies form in the moving cloud field.

Earth Observation taken during the Expedition 36 mission

ISS036-E-035663 (24 Aug. 2013) --- One of the Expedition 36 crew members aboard the International Space Station recorded this still image of unusual cloud patterns surrounding Guadalupe Island in the Pacific Ocean (left center). These are the result of a ubiquitous occurrence in the motion of fluids—a vortex street, which is a linear chain of spiral eddies called von Karman vortices. Von Karman vortices are named after Theodore von Karman, a co-founder of NASA's Jet Propulsion Laboratory. who first described the phenomenon in the atmosphere. Guadalupe Island or Isla Guadalupe is a volcanic island located 241 kilometers (150 statute miles) off the west coast of Mexico's Baja California peninsula.

Earth observations taken during STS-83 mission

STS083-749-079 (4-8 April 1997) --- Cloud wake covers the Leeward Islands. Like a ship making a wake in the water, Guadeloupe Island is making a wake in the clouds. Seeing certain weather features tells us information as to what the conditions were at the time the photo was taken. For instance, a solid cloud area is formed behind the island in this photo so the winds are under or at 5 meters per second (mps). If the winds were greater Von Karman Vortices would develop. Formation of Von Karman Vortices requires wind speeds of 5 and 13 mps and a strong low level temperature inversion below the highest peak of the island.

ISS040-E-016569 (21 June 2014) --- From an altitude of 223 nautical miles, one of the Expedition 40 crew members on the International Space Station photographed this nearly vertical image of Guadalupe Island and the Von Karman cloud vortices that are its storied neighbors just off southern California's Pacific Coast.

Earth Observation

ISS040-E-016570 (21 June 2014) --- From an altitude of 223 nautical miles, one of the Expedition 40 crew members on the International Space Station photographed this nearly vertical image of Guadalupe Island and the Von Karman cloud vortices that are its storied neighbors just off southern California's Pacific Coast.

Earth Observation

Earth Observations taken by the Expedition 15 Crew

ISS015-E-09199 (23 May 2007) --- Von Karman cloud vortices near the Aleutian Islands are featured in this image photographed by an Expedition 15 crewmember on the International Space Station. The vortices are created by the wind encountering a barrier such as an island, changing direction and velocity and forming eddies in the wind and cloud pattern on the lee side of the island. The nadir point of the space station when the image was taken was 51.1 degrees north latitude and 178.8 degrees west longitude.

Earth Observation

ISS040-E-016422 (20 June 2014) --- One of the Expedition 40 crew members aboard the International Space Station used a 28mm focal length to record this long stretch of California's Pacific Coast on June 20, 2014. Guadalupe Island and the surrounding von Karman cloud vortices over the Pacific can be seen just above frame center. San Diego is visible in upper left and the Los Angeles Basin is just to the left of center frame. Much of the Mojave Desert is visible in bottom frame.

Volcanic Plume from Mt. Unzen, Dust Cloud, cloud Vortices

Stable, south flowing air over the western Pacific Ocean (26.0N, 131.0E) is disturbed by islands south of Korea, resulting in sinuous clouds known as von Karman vortices. The smoke plume from Japan's Mount Unzen Volcano on Kyushu, is visible just west of the large cloud mass and extending southward. A very large, purple tinged dust pall, originating in Mongolia, can be seen on the Earth's Limb, covering eastern China and extending into the East China Sea.

Swirl of Clouds over the Pacific

Theodore von Kármán, a Hungarian-American physicist, was the first to describe the physical processes that create long chains of spiral eddies like the one shown above. Known as von Kármán vortices the patterns can form nearly anywhere that fluid flow is disturbed by an object. Since the atmosphere behaves like a fluid, the wing of an airplane, a bridge, even an island can trigger the distinctive phenomenon. On May 22, 2013, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image of cloud vortices behind Isla Socorro, a volcanic island located in the Pacific Ocean. The island, which is located a few hundred kilometers off the west coast of Mexico and the southern tip of Baja California, is part of the Revillagigedo Archipelago. Satellite sensors have spotted von Kármán vortices around the globe, including off of Guadalupe Island, near the coast of Chile, in the Greenland Sea, in the Arctic, and even next to a tropical storm. NASA image courtesy Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response Team at NASA GSFC. Caption by Adam Voiland. Instrument: Terra - MODIS More info: <a href="http://1.usa.gov/14VSDQa" rel="nofollow">1.usa.gov/14VSDQa</a> Credit: <a href="http://www.earthobservatory.nasa.gov/" rel="nofollow"> NASA Earth Observatory</a> <a href="http://www.nasa.gov/audience/formedia/features/MP_Photo_Guidelines.html" rel="nofollow">NASA image use policy.</a> <a href="http://www.nasa.gov/centers/goddard/home/index.html" rel="nofollow">NASA Goddard Space Flight Center</a> enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on <a href="http://twitter.com/NASA_GoddardPix" rel="nofollow">Twitter</a> Like us on <a href="http://www.facebook.com/pages/Greenbelt-MD/NASA-Goddard/395013845897?ref=tsd" rel="nofollow">Facebook</a> Find us on <a href="http://instagram.com/nasagoddard?vm=grid" rel="nofollow">Instagram</a>

Earth Observations taken by Expedition 41 crewmember

ISS041-E-016962 (18 Sept. 2014) --- Although land and waters of Mexico's Pacific area pictured here are influenced by masses of clouds, for Baja California and other parts of Mexico in this photograph made from the International Space Station, things are quite calmer than a few days ago when Hurricane Odile unleashed its power on the peninsula, especially Baja's south end (right side of frame) and Cabo San Lucas (just out of frame right). The Sea of Cortez (Gulf of California) experiences rather calm weather in this view. California's Salton Sea is visible at left center; and Guadalupe Island is visible at lower left, surrounded by von Karman vortices.

$NASA image acquired September 15, 1999 This Landsat 7 image of clouds off the Chilean coast near the Juan Fernandez Islands (also known as the Robinson Crusoe Islands) on September 15, 1999, shows a unique pattern called a “von Karman vortex street.” This pattern has long been studied in the laboratory, where the vortices are created by oil flowing past a cylindrical obstacle, making a string of vortices only several tens of centimeters long. Study of this classic “flow past a circular cylinder” has been very important in the understanding of laminar and turbulent fluid flow that controls a wide variety of phenomena, from the lift under an aircraft wing to Earth’s weather. Here, the cylinder is replaced by Alejandro Selkirk Island (named after the true “Robinson Crusoe,” who was stranded here for many months in the early 1700s). The island is about 1.5 km in diameter, and rises 1.6 km into a layer of marine stratocumulus clouds. This type of cloud is important for its strong cooling of the Earth’s surface, partially counteracting the Greenhouse warming. An extended, steady equatorward wind creates vortices with clockwise flow off the eastern edge and counterclockwise flow off the western edge of the island. The vortices grow as they advect hundreds of kilometers downwind, making a street 10,000 times longer than those made in the laboratory. Observing the same phenomenon extended over such a wide range of sizes dramatizes the “fractal” nature of atmospheric convection and clouds. Fractals are characteristic of fluid flow and other dynamic systems that exhibit “chaotic” motions. Both clockwise and counter-clockwise vortices are generated by flow around the island. As the flow separates from the island’s leeward (away from the source of the wind) side, the vortices “swallow” some of the clear air over the island. (Much of the island air is cloudless due to a local “land breeze” circulation set up by the larger heat capacity of the waters surrounding the island.) The “swallowed” gulps of clear island air get carried along within the vortices, but these are soon mixed into the surrounding clouds. Landsat is unique in its ability to image both the small-scale eddies that mix clear and cloudy air, down to the 30 meter pixel size of Landsat, but also having a wide enough field-of-view, 180 km, to reveal the connection of the turbulence to large-scale flows such as the subtropical oceanic gyres. Landsat 7, with its new onboard digital recorder, has extended this capability away from the few Landsat ground stations to remote areas such as Alejandro Island, and thus is gradually providing a global dynamic picture of evolving human-scale phenomena. For more details on von Karman vortices, refer to <a href="http://climate.gsfc.nasa.gov/~cahalan" rel="nofollow">climate.gsfc.nasa.gov/~cahalan</a>. Image and caption courtesy Bob Cahalan, NASA GSFC Instrument: Landsat 7 - ETM+ Credit: NASA/GSFC/Landsat <a href="http://www.nasa.gov/centers/goddard/home/index.html" rel="nofollow">NASA Goddard Space Flight Center</a> enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on <a href="http://twitter.com/NASA_GoddardPix" rel="nofollow">Twitter</a> Join us on <a href="http://www.facebook.com/pages/Greenbelt-MD/NASA-Goddard/395013845897?ref=tsd" rel="nofollow">Facebook</a>$

Large-scale Fractal Motion of Clouds

NASA image acquired September 15, 1999 This Landsat 7 image of clouds off the Chilean coast near the Juan Fernandez Islands (also known as the Robinson Crusoe Islands) on September 15, 1999, shows a unique pattern called a “von Karman vortex street.” This pattern has long been studied in the laboratory, where the vortices are created by oil flowing past a cylindrical obstacle, making a string of vortices only several tens of centimeters long. Study of this classic “flow past a circular cylinder” has been very important in the understanding of laminar and turbulent fluid flow that controls a wide variety of phenomena, from the lift under an aircraft wing to Earth’s weather. Here, the cylinder is replaced by Alejandro Selkirk Island (named after the true “Robinson Crusoe,” who was stranded here for many months in the early 1700s). The island is about 1.5 km in diameter, and rises 1.6 km into a layer of marine stratocumulus clouds. This type of cloud is important for its strong cooling of the Earth’s surface, partially counteracting the Greenhouse warming. An extended, steady equatorward wind creates vortices with clockwise flow off the eastern edge and counterclockwise flow off the western edge of the island. The vortices grow as they advect hundreds of kilometers downwind, making a street 10,000 times longer than those made in the laboratory. Observing the same phenomenon extended over such a wide range of sizes dramatizes the “fractal” nature of atmospheric convection and clouds. Fractals are characteristic of fluid flow and other dynamic systems that exhibit “chaotic” motions. Both clockwise and counter-clockwise vortices are generated by flow around the island. As the flow separates from the island’s leeward (away from the source of the wind) side, the vortices “swallow” some of the clear air over the island. (Much of the island air is cloudless due to a local “land breeze” circulation set up by the larger heat capacity of the waters surrounding the island.) The “swallowed” gulps of clear island air get carried along within the vortices, but these are soon mixed into the surrounding clouds. Landsat is unique in its ability to image both the small-scale eddies that mix clear and cloudy air, down to the 30 meter pixel size of Landsat, but also having a wide enough field-of-view, 180 km, to reveal the connection of the turbulence to large-scale flows such as the subtropical oceanic gyres. Landsat 7, with its new onboard digital recorder, has extended this capability away from the few Landsat ground stations to remote areas such as Alejandro Island, and thus is gradually providing a global dynamic picture of evolving human-scale phenomena. For more details on von Karman vortices, refer to <a href="http://climate.gsfc.nasa.gov/~cahalan" rel="nofollow">climate.gsfc.nasa.gov/~cahalan</a>. Image and caption courtesy Bob Cahalan, NASA GSFC Instrument: Landsat 7 - ETM+ Credit: NASA/GSFC/Landsat <a href="http://www.nasa.gov/centers/goddard/home/index.html" rel="nofollow">NASA Goddard Space Flight Center</a> enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on <a href="http://twitter.com/NASA_GoddardPix" rel="nofollow">Twitter</a> Join us on <a href="http://www.facebook.com/pages/Greenbelt-MD/NASA-Goddard/395013845897?ref=tsd" rel="nofollow">Facebook</a>