Study On Comparison The Characteristics Of Sandy Weather And Aerosol Physics Properties In China And Korea

Atmospheric aerosol is closely related with other environmental problems, and has special effect on the health of human and other creatures. Sand-dust aerosol often takes place in the northern part of East Asia, where the weather is quite dry. Especially in spring, sand-dust aerosol affects China and Korea. The influence of sandy weather on human life and the ecological environment has attracted much attention from society and the government.This study evaluated the characteristics of sandy weather and atmospheric aerosol physics properties in China and Korea using statistical methods, diagnostic analyzes and numerical simulation, satellite retrieval data (MODIS,MISR and TOMS), PM10, TSP, and AERONET data. The results are as follow:Firstly, sandstorms happened mostly in spring and summer in 1960 to 2005 in China. After the 1970s, there were gradually fewer sandstorms. In Korea, sandy weather happened mainly in spring. After 2000, there is a trend of more sandy weather. It was 33.7% that sandy weather of China influenced to Korea under the same weather system from 2000 to 2006.Secondly, the source and transmission path of sandy weather in China and Korea were nearly the same. There were 4 types of source and transmission path of the sandy weather in Korea. The first path (near Hunshandake desert) was the one that affects Korea most. Under sandy weather, there forms a northwesterly wind in both upper- and lower- level near Korea, which helps the transmission of sand. The second path (near Badain Jaran shamo) had close relationship with the upper-level jet stream. The upper-level wind above Korea was usually the westerly wind, while the low-level wind was the northwesterly wind. Most sand was probably transmitted in the upper place and then descends. The third path (near Kerqin sand land) was related to secondary cold front. It takes about 12 hours for sand to be transmitted by the northwest wind to Korea after a sand weather took place in the source. The time it costs was the least. The fourth path (near Gobi and hungriness in middle Mongolia) had similar features as the first path. For this path, China had extensive sand weather while Korea was less affected.Thirdly, TOMS aerosol index had obvious seasonal change, which properly described the sand aerosol in spring and combustion aerosol in winter. Aerosol index can be used to monitor the beginning, developing and transmission of sand weather. Besides, aerosol index was not affected by clouds, so it can accurately work in the area covered by clouds.Fourthly, in the eastern part of China, MODIS and MISR atmospheric aerosol optical thickness (AOD) was bigger in spring and summer, while AOD in autumn and winter was smaller. MODIS AOD can measure sand aerosol well and MISR AOD can measure well above the sea and in the western part of China. So when the two are combined together, it will be better for studying the atmospheric aerosol.In spring, the wind field around Korea was mainly a northwesterly flow, while in summer it was west-southwestern flow. This fact leaded sand aerosols of the northern part of China and Mongolia and industrial aerosols of the eastern part of China to be transmitted to Korea well. In spring, the daily average trend of the PM10 and MODIS AOD in Beijing and Anmyon coincide with each other, but PM10 and MODIS AOD in Beijing were a little bigger than in Anmyon.Fifthly, the monthly average maximum AOD from AERONET atmospheric aerosol data appeared in spring and summer in Beijing and Anmyon, and the minimum appeared in autumn and winter. The AOD in Beijing is higher than that in Anmyon. The fine mode AOD in the two districts was higher than that of coarse mode. In Anmyon, the fine mode AOD in spring and summer was a little higher than that in autumn and winter and the coarse mode AOD in spring was higher than that in the other three seasons. In Beijing, fine mode AOD remained highly in four seasons. Its seasonal trend was similar with that in Anmyon, while the value of AOD was higher in general. Aerosol volume size distribution appeared two forms, the one urban/industrial aerosol, that is, fine mode particle is more. The other is sand aerosol, that is, coarse particle mode was more. For predominately fine mode AOD cases, aerosol volume sizes of fine mode particle were similar that of coarse mode particle, while aerosol volume sizes of coarse mode particle were greater than fine mode particle, for predominately coarse mode AOD cases. In spring, coarse mode particle appeared more in both Beijing and Anmyon, while in summer, fine particle appeared more. They were nearly equal in autumn and winter. The volume size of coarse mode was more in Beijing than that in Anmyon, while that of the fine particle was almost the same in two districts.