And every year, they pollute the rest of us.
Excerpt:
China - April 6 and 7 - A series of huge sandstorm events called "the worst of the spring season" develop over Mongolia and sweep across western China reducing visibilities to near zero and making ground transportation all but impossible. The resulting huge aerosol cloud mass is picked up by orbiting earth satellites as it forms over China and heads out to sea.
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This Asian Haze event has been officially confirmed by:
* Jay R. Herman, Principal Investigator for TOMS Aerosol/UV projects, NASA/Goddard Space Flight Center
* Officials at the Naval Research Laboratory in Monterey, California
* Gene Feldman, NASA/Goddard Space Flight Center
* Russ Schnell, Director of Observatory Operations, NOAA, Boulder, Co.
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On April 6 and 7, a series of huge sandstorm events developed over Mongolia and swept across western China and subsequently produced a huge aerosol cloud that was observed by orbiting earth satellites.
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Dangerous Levels of Metallic Substances detected in latest 'yellow dust' from China
[Mar. 10, 2001]
"The latest seasonal winds from China, known as "yellow dust," which blanketed the nation earlier this week twice, carried 16 times more metallic substances than last year's, a research institute said yesterday, sounding health alarms over the dust mass.
There are no immediate measures to prevent the coming of the so-called "gatecrasher of spring" that causes eye, nose and respiratory illnesses. Experts say that it is best to remain indoors and if one has to go out, to wear a mask.
The yellow dust phenomenon happens after sandstorms are created in the inland deserts in northern China, usually during dry spring weather, by strong convection of currents of warm and cold air that sweeps soil particles up to high altitudes.
They typically rise to a height of 3 km to 5 km before blowing eastward at some 30 meters per second, crossing the West Sea before arriving in South Korea in two to three days.
In addition to potential health problems, the dust in extreme cases can cause visibility problems for pilots, hinder the operation of precision machinery and impair the growth of agricultural products.
There were reports the dust may have carried the viruses that caused a deadly foot-and-mouth epidemic that hit the nation's livestock industry last year.
NASA sets up it's own annual tracking of this mysterious dust cloud event:
Background about the China Dust Storm
A Siberian cold front caused large dust storms to be created in northwestern China's Inner Mongolia region and Gansu province. As these storms hovered over northern China, they ushered in the worst period of air pollution in six years. Air quality in the capital city of Beijing reached hazardous levels, and elderly people and children were warned to stay indoors. At this latitude on the globe the air moves from west to east, so the dust storm which originated in China will move towards Japan. However, the storm is expected to weaken as it enters the Bohai Sea and the East China Sea. South Korea, which also lies in the storm's path, was also greatly affected, and the storm was its second-worst this year. The dust is actually a combination of sand from the Gobi Desert and chemicals from Chinese industrial cities that blow to the Korean Peninsula from westerly winds in April and May, reducing visibility and filling the country's skies with a thick blanket.