제주도 한라산 강수성분의 산성화 및 중화 기여도 조사

From 2011 to 2013, precipitation samples were collected at the 1100 m Site of Mt. Halla on Jeju Island, Korea, which is a background site located in the upper atmospheric boundary layer. To investigate the chemical compositions and pollution characteristics of precipitation, ionic species were analyzed. In the comparison of ion balance, electrical conductivity, and the acid fraction, the correlation coefficients were high (> 0.9), representing good reliability of the analytical data. The volume-weighted mean pH and electrical conductivity of the precipitation samples were 4.95 and 15.1 μS/cm, respectively. Furthermore, the ionic strength of precipitation was 0.15 ± 0.17 mM, indicating that about 46.6% of all precipitation samples were within the pure precipitation criteria. The acidification contributions by sulfuric acid and nitric acid were 58.8% and 32.6%, respectively, while that of organic acids, such as formic and acetic acids, was 8.7%. Meanwhile, the neutralization factors by ammonia and calcium carbonate were 30.1% and 25.2%, respectively. The clustered back trajectory analysis showed that the concentrations of the major precipitation species were relatively higher when the air masses originated in continental China and the Korean Peninsula, compared to the case of inflow from the North Pacific Ocean.