Temporal variation and cause of acidic precipitation from a monitoring network in Korea

We have been measuring precipitation acidity using samples collected from several, remotely located stations in Korea. Among those stations, most intensive measurements were made from two sites located in rural areas of Chongwon, Choongbook Province of Korea from the periods of May 1990 to June 1993. Our analyses of annual volume-weighted mean values of pH from the two monitoring sites at Chongwon showed a clear trend of enhancing acidification with time. Similar temporal trends were also apparent from other remotely located sampling stations. Our results of acidic precipitation strongly suggest that precipitation acidification is a widespread phenomenon over the vast areas of Korea. Using backward trajectory data, relationships between the meteorological factors and wet deposition chemistry of atmospheric pollutants have also been investigated. The results of our investigation indicate that the long-range transport of atmospheric pollutants from China may exert a dominant control over the acidic precipitation in the Korean Peninsula.