Unusual wind patterns caused dust storms to double back

The sandy and dusty weather that has affected most parts of China for a week was caused by a larger amount of sand and dust due to less snow cover, which was then driven back across the country by strong winds, experts from the National Satellite Meteorological Center said on Thursday.

Since Sunday, the sandstorm, which originated in Mongolia, has hit many parts of the country, spreading from Northeast China's Heilongjiang province to as far south as the Yangtze River Basin, causing heavy airborne pollution and low visibility.

The level of PM10 — hazardous particles less than 10 microns in diameter — reached a concentration of more than 2,000 mcg/cubic m in parts of northern China, the National Meteorological Center said.