Physical and hygroscopic properties and CCN characteristics of the aerosols measured at an island in the northwestern tip of South Korea

Atmospheric aerosols have drawn great attention in recent decades for their direct and indirect effects on climate. Particularly, Asian regions of rapid industrialization are well-known for transporting enormous air pollution aerosols throughout the Pacific. As an effort to monitor the physical and hygroscopic properties of Asian continental anthropogenic aerosols, we measured total aerosol (CN) concentration, hygroscopicity and cloud condensation nuclei (CCN) concentration for about a month (August) in 2009 at a hilly site in Baekryeong Island, located at the northwestern tip of South Korea (N 37°52’, E 124°53’). Since local anthropogenic disturbance is minimal, the site is ideal for monitoring Asian continental outflow when the prevailing wind is from the west. In this study CCN characterization was also attempted. Critical supersaturation (SC) of ambient aerosols of selected diameters of 75nm and 100nm were measured with a DMA-CCN Counter setting. SC, hygroscopicity, and CCN/CN ratios are combined to estimate the CCN capability of these aerosols. Preliminarily the daily mean CN concentration varied from 2768 to 8626 cm-3 while CCN concentration at 1% supersaturation varied from 1571 to 7492 cm-3. The average of CCN/CN ratio was approximately 0.8. The 75 nm ambient particles had the SC range from 0.20 to 0.50 % whereas the 100 nm ambient particles had the SC range from 0.13 to 0.32. More detailed analysis will be shown at the conference.