ON SAND AND DUSTSTORMS AND ASSOCIATED SIGNIFICANT DUSTFALL OBSERVED IN CHONGJU-CHONGWON, KOREA DURING 1997–2000


    loading  Checking for direct PDF access through Ovid

Abstract

Monitoring of the occurrence of sandstorms and dustfall phenomena from 1997 to 2000 was carried out. We refer to sandstorms, duststorms and blowing sand as the phenomena occurring in the source region, while significant dustfall is the phenomenon that occur in the sink area. It was noted that while the sandstorms in deserts and loess in NW-N China and Mongolia occurred any time during the year while severe sandstorms occurred frequently from March to May after the spring thaw. The wind erosion in the source region usually occurred with wind speeds greater than 8 ms-1. However, severe sandstorm phenomenon occurred with wind greater than 15 ms-1 for at least 3 hr or more. In the source regions, sandstorms occurred over 60–120 days per year. In Mongolia, the observation of the number of sandstorm days decreased due to the increase in rainy days. When a dust cloud from a desert reached the sink region, significant dustfall in the Korean Peninsula occurred due to the lack of strong winds. We defined the episode of significant dustfall (SD) with the following values: TSP ≥250, PM10 ≥190 μg m-3 and visibility 6.5 km or less. In Korea, 8–12 episodes of SD occurred per year with 12 to 22 SD days. The maximum concentrations of TSP recorded were 989–1396 μg m-3 with PM10 values of 861–996 μg m-3 and with the lowest visibility of 1.4–1.6 km.

    loading  Loading Related Articles