Recent frequent dust events and their relation to surface wind in East Asia

A remarkable increase in dust outbreaks has occurred in the eastern part of the Asian Continent over the last three years (2000-2002) compared with the previous seven years (1993-1999). This finding corresponds well with the annual change of Kosa (i.e., yellow sand) events for the same period in Japan. Dust outbreaks occurred in limited regions around southern Mongolia, the Badain Jaran Desert, and the western Loess Plateau from 1993-1999. However, the area of frequent dust outbreaks expanded extensively to the east, and dust outbreaks also frequently occurred in regions around the North China Plain, northeastern China, and the Korean Peninsula in 2000-2002. Good correspondence was found between the surface wind and dust outbreaks in year-to-year variations and in spatial distributions. This indicates that frequent strong winds are the primary cause of the recurrent dust outbreaks in the last three years.