| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1998: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1997: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Research Abstract |
Air at Fukui in 1993 was traced by Inverse-Trajectory method. Air at Fukui comes from China mainland from October to May when Siberian anticyclone is superior. In July and August air comes from Pacific Ocean, while June and September air comes from almost all directions.
SO_2 load in East Asia was estimated by Akimoto et al^<1)>. Using Eliassen's dispersion and chemical reaction formulae, origin of acid deposition to Fukui was estimated. Fukui is situated close to the Japan Sea so that contribution of China mainland reaches up to 90%, but during summer season no pollution comes from China. Not only artificial sources, but also volcanoes discharge SO_2 in the air. In Kyushu Islands amount of SO_2 discharged by volcanoes is much more than artificial ones. Sakurajima, Aso, Suwanosejima are three main volcanoes whose SO_2 release affect the acid deposition at Fukui. In 1993, maximum portion of volcanic vent to total acid deposition at Fukui was about 40%, but if center of volcanic smoke hits Fukui, SO_22 due to volcanoes may reach up to 70%.
Reference :
1) H.Akimoto and H.Narita : " Distribution of SO_2 NO_x and CO_2 Emission from Fuel Combustion and Industrial Activities in Asia with 1ﾟ*1ﾟ Resolution", Atmospheric Environment, 28, 213-225 (1994)
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