On the occurrence of yellow sand and atmospheric loadings

The phenomena of yellow sand (dust cloud) which occurred in Korea during the springs of 1993 and 1994 were studied in detail. In 1993, there were six cases which lasted a total of 15 days, while only three cases of yellow sand were observed in 1994—mainly by aircraft. It was found that the chief layer of a dust cloud usually travelled in the level between 1000 and 3000 m and moved to the east and southeast by a steering airflow at 850-500 hPa. The lower visibility with yellow sand was often observed during daytime than nighttime. Also, the area covered by a vast dust cloud once exceeded 0.6 Mkm2. The estimated atmospheric loadings for this cloud were 1.5 Mton.