Estimation of nitrogen dry deposition in South Korea

Dry deposition of nitrogen over South Korea has been estimated using a simplified chemical model and the K-mean clustering technique. The three consecutive daily mean National Center for Environmental Protection (NCEP) reanalyzed 850 hPa geopotential height fields without precipitation on the last day over South Korea are used for clusterings of synoptic patterns for the period of 1994-1998. The estimated long-term dry deposition of nitrogen by aggregating each cluster over South Korea is found to be about 530 eq ha(-1) yr(-1) of which 30%, 23%, 19%, 18% and 9% are contributed by HNO3, NH4+, NO2, NH3 and NO3- nitrogen species, suggesting the importance of secondary pollutants of nitrogen species for dry deposition of nitrogen. (C) 2002 Elsevier Science Ltd. All rights reserved.