Composition and Pollution Characteristics of Precipitation in Jeju Island, Korea for 1997–2015

Abstract

This study focuses on the long-range chemical composition and pollution characteristics of precipitation components. Samples were collected from Jeju Island in 1997–2015, and their major ionic components were analyzed. Comparison of ion balance, electrical conductivity, and acid fraction of precipitation samples yielded correlation coefficients in the range of 0.937–0.980. The volume-weighted mean pH and electrical conductivity of the wet precipitation of the Jeju area were 4.81 and 21.7 μS/cm, respectively. Ionic strengths of the wet precipitation samples were within the range of 0.24 ± 0.26 mM, indicating that more than 30% of the total precipitation satisfied the pure precipitation criterion. Of the total precipitation in the Jeju area, 44% exhibited a pH in the range of 4.5–5.0, indicating weak acidity. The composition of sea salts and secondary pollutants in the precipitation were 56.8% and 28.7%, respectively, indicating that the precipitation in the Jeju area was affected by the surrounding coastal area. The acidity contributions by inorganic and organic acids were 92.3% and 7.7%, respectively, whereas, the neutralization factors for ammonia and calcium carbonate were 47.0% and 20.0%, respectively. Clustered back trajectory analysis indicates that the concentrations of most ionic components were higher in the airflow pathways to the Jeju area.