Dust devil - Definition and Overview

Dust Devil
Johnsonville, South Carolina

A dust devil is a rotating updraft, 1000 meters or more high and tens of meters in diameter. Dust devils are often observed in times of atmospheric turbulence, especially common in the San Luis Valley of Colorado. They are visible in the Great Basin and eastward to El Paso, for example. They are distinct from the common dust storms of this area, because they resemble small tornados. Due to this they are best viewed from a distance, and at a height (say, from a mountaintop). These whirlwinds are not extremely hazardous to biological organisms, but machines and electronics can suffer many severe malfunctions through repeated exposure to dust devil activity, including but not limited to physical damage or increased wear from dust and short circuits or other physical damage caused by electrical arcing.

It was recently found that even small dust devils (on Earth) can produce radio noise and electrical fields greater than 10,000 volts per meter.[1] (http://www.berkeley.edu/news/media/releases/2002/05/29_dust.html)

In Australia, dust devils are commonly known as willy willies, from an Aboriginal word.

Mars

A dust devil on Mars, photographed by Mars Global Surveyor. The long dark streak is formed by a moving swirling column of Martian atmosphere. The dust devil itself (the black spot) is climbing the crater wall. The streaks on the right are sand dunes on the crater floor.

Dust devils also occur on Mars, and were first photographed by the Viking orbiters in the 1970s. In 1997, the Mars Pathfinder lander detected a dust devil passing over it.[2] (http://www.ruhr-uni-bochum.de/climusa/dust.htm) Martian dust devils can be up to fifty times as wide and ten times as high as terrestrial dust devils, and large ones may pose a threat to terrestrial technology sent to Mars.[3] (http://unisci.com/stories/20012/0606012.htm)