Weird Clouds Look Even Better From Space


Cloud Streets, Bering Strait

Wind is chilled as it moves across sea ice in the Bering Strait, and when this cold air hits the the open ocean, parallel rows of clouds known as cloud streets are formed.

The streets are the result of the interaction of the dry, chilled wind with the warmer, wetter air over the water. The warm air rises and is cooled by the wind, which causes the water vapor in it to condense into clouds. At the same time, the cool air sinks, which sets up long rotating cylinders of air where clouds are formed on the upward moving sides, and the air stays clear on the downsides. This creates the long, alternating rows of clouds and clear air seen in the image of the Bering Strait taken in January 2010 by the MODIS instrument on NASA’s Terra satellite.

Below is a closer view of cloud streets in the Bering Strait captured by Terra on January 20, 2006, and below that an image of cloud streets in the same area the next day. At the bottom is an image of cloud streets forming off the Amery Ice Shelf in Antarctica, taken by NASA’s Aqua satellite in August 2006.




Images: 1) Jeff Schmaltz/NASA. 2, 3, 4) Jesse Allen/NASA.

Ship Tracks, Pacific Ocean

The maze of cloud streams in this image is the result of exhaust from ship engines. The clouds form when water vapor condenses onto particles in the exhaust, which act as seeds for the clouds. The ship tracks are brighter than the other clouds in the image, because they are made of more plentiful, smaller particles.

The image above was taken in March 2009 over the Pacific Ocean south of Alaska by the MODIS instrument on NASA’s Terra satellite. The tracks below were captured by Terra in the same area in April 2002. Below that is an image of ship tracks in the Pacific Ocean near the northwest coast of North America taken by the Aqua satellite in January 2008.



Images: 1) Jeff Schmaltz/NASA. 2) Jacques Descloitres/NASA. 3) Jesse Allen/NASA.

Open- and Closed-Cell Clouds, Pacific Ocean

The honeycomb pattern in the image above is made up of stratocumulus clouds with open cells that look like voids surrounded by thin clouds, and closed cells that look like cotton balls surrounded by strips of open space. The empty-looking open cells occur when closed-cell clouds begin to produce a light drizzle. Fields of these cells are difficult to see from the ground, but are spectacular from space. The clouds pictured above were imaged by the MODIS instrument on NASA’s Aqua satellite over the Pcific Ocean near Peru on April 17, 2010.

In the image below, open- and closed-cell clouds can be seen along with closely related actinoform clouds. The actinoform pattern, near the center of the image, has rays that look like the veins on a leaf. This image of clouds off the west coast of South America was captured by the MODIS instrument on NASA’s Terra satellite in September 2005.


Images: 1) Jeff Schmaltz/NASA. 2) Jesse Allen/NASA.

Glory, Baja California

The images above and below show a spectacular phenomenon known as a glory, which is a rainbow-like ring pattern caused by the scattering of sunlight by clouds made of liquid water droplets that are less than 50 micrometers across and all about the same size. These images were taken when a satellite passed directly between the sun and the clouds.

In the image above, captured by the MODIS instrument on NASA’s Aqua satellite in May 2008, the glory runs down the center. The red and orange colors are easiest to see, and the band of color is around 37 miles wide. There is also a bonus von Kármán vortex street created by Guadalupe Island in the upper right of the picture.

The image below shows a slightly less-visible glory, as well as von Kármán vortices behind Guadalupe Island. This shot was taken in June 2007 by NASA’s Terra satellite.


Images: 1) Jesse Allen/NASA. 2) Jeff Schmaltz/NASA.

Lake Effects, Aral Sea and Great Lakes

The Aral Sea created an unusual pattern of wave clouds in the image above, captured by NASA’s Aqua satellite in March 2009. Wave clouds themselves aren’t especially rare, but they are usually formed when high topography (such as a mountain) or a strong updraft of air causes a disturbance in a cloud layer. Here, the shore of the Aral Sea is clearly creating the disturbance, which could be the result of a sudden uptick in wind speed as the air reaches the smooth surface of the lake, or by the shoreline which has steadily been growing higher than the water surface as the Aral Sea shrinks over time.

A more typical lake effect is seen in the image below of the Great Lakes region of North America, taken by the sea-viewing wide field-of-view sensor (SeaWiFS) aboard GeoEye’s SeaStar satellite in December 2000. As cold air flows northwest across the relatively warm Lakes Nipigon (top left), Superior, and Michigan, the warm, moist air rises and mixes with with the cold, dry wind forming a stratocumulus cloud layer. As the process continues, the water droplets in the cloud layer may freeze and grow into snowflakes, sometimes creating massive snowstorms.


Images: 1) Jeff Schmaltz/NASA. 2) GeoEye/SeaWiFS.

Hurricane Bill, Atlantic Ocean

Hurricane Bill was one of the largest Atlantic tropical cyclones on record and grew to a maximum diameter of 460 miles. This image of Bill was taken August 20, 2009 NASA’s Terra satellite when the storm was northeast of Puerto Rico and had sustained winds of 120 miles an hour.

Image: Jeff Schmaltz/NASA.

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Island Effect, Greenland Sea

Jan Mayen island is creating spectacular von Kármán vortices in a otherwise uniform set of parallel cloud streets in the Greenland Sea. Like the islands on the first page of this gallery, Jan Mayen is interrupting the flow of air and causing the clouds streaming by to break into eddies swirling in opposite directions in its wake. The coast of Greenland and protruding sea ice is visible in the upper left of this image taken in February 2009 by the MODIS instrument on NASA’s Aqua satellite.

Image: Jeff Schmaltz/NASA