Kim, Najin Park, Minsu Yum, Seong Soo Park, Jong Sung Song, In Ho Shin, Hye Jung Ahn, Joon Young Kwak, Kyung-Hwan Kim, Hwajin Bae, Gwi-Nam Lee, Gangwoong 2024-01-20T02:02:58Z 2024-01-20T02:02:58Z 2021-09-01 2017-03 1352-2310 https://pubs.kist.re.kr/handle/201004/123029 Aerosol physical properties, chemical compositions, hygroscopicity and cloud condensation nuclei (CCN) activities were measured in Seoul, the highly populated capital city of Korea, during the Megacity Air Pollution Studies (MAPS-Seoul) campaign, in May-June 2015. The average aerosol concentration for particle diameters >10 nm was 11787 +/- 7421 cm(-3) with dominant peaks at morning rush hours and in the afternoon due to frequent new particle formation (NPF) events. The average CCN concentration was 4075 +/- 1812 cm(-3) at 0.6% supersaturation, with little diurnal variation. The average hygroscopicity parameter (K) value determined using a humidified tandem differential mobility analyzer (HTDMA) ranged 0.17-0.27 for a range of particle diameters (30-150 nm). The K values derived using the aerosol mass spectrometer (AMS) data with three different methods were 0.32-0.34, significantly higher than those from HTDMA due to the uncertainties in the hygroscopicity values of different chemical compositions, especially organics and black carbon. Factors affecting the aerosol hygroscopicity seemed to be traffic and chemical processes during the NPF events. The CCN concentration predicted based on HTDMA K data showed very-good agreement with the measured one. Because of the overestimation of K, CCN closure with the predicted CCN concentration based on AMS K data over-predicted CCN concentration although the linear correlation between measured and predicted CCN concentration was still very good. (C) 2017 Elsevier Ltd. All rights reserved. English PERGAMON-ELSEVIER SCIENCE LTD CHEMICAL-COMPOSITION ORGANIC AEROSOL PARTICLE HYGROSCOPICITY SOOT PARTICLES CCN ACTIVITY GROWTH SIZE PARAMETER NUMBER SITE Hygroscopic properties of urban aerosols and their cloud condensation nuclei activities measured in Seoul during the MAPS Seoul campaign Article 10.1016/j.atmosenv.2017.01.034 1 ATMOSPHERIC ENVIRONMENT, v.153, pp.217 - 232 ATMOSPHERIC ENVIRONMENT 153 217 232 scie scopus 000395354400020 2-s2.0-85010470208 Environmental Sciences Meteorology & Atmospheric Sciences Environmental Sciences & Ecology Meteorology & Atmospheric Sciences Article CHEMICAL-COMPOSITION ORGANIC AEROSOL PARTICLE HYGROSCOPICITY SOOT PARTICLES CCN ACTIVITY GROWTH SIZE PARAMETER NUMBER SITE Aerosol hygroscopicity Urban aerosol Cloud condensation nuclei activity Ground measurement MAPS-Seoul