Evaluation of precipitation composition at an urban and a rural area for the central Korean peninsula

Precipitation samples were collected using wet-only samplers on a daily bas is at Chunchon (rural area) and Seoul (urban area) from January to December in 1998. The pH, electrical conductivity, and the concentrations of major ions were analyzed. The volume-weighted annual average values of pH for bot h sites were identical. However, for volume weighted average pH of precipit ations below 20 mm in Chunchon was significantly (p<0.05) lower than that i n Seoul. The value of [NO3-]/[nss-SO42-], calculated from average compositi on of rainfalls below 20mm, were 0.42 and 0.61 in Seoul and Chunchon, respe ctively. This supports that acidification of precipitation by nitrogen oxid es, a part of which might be transported from the Seoul metropolitan area, caused the difference in pH between Chunchon and Seoul.