ACP Atmospheric Chemistry and Physics ACP Atmos. Chem. Phys. 1680-7324 Copernicus Publications Göttingen, Germany 10.5194/acp-14-8763-2014 On the submicron aerosol distributions and CCN number concentrations in and around the Korean Peninsula Kim J. H. 1 Yum S. S. 1 Shim S. 1 Kim W. J. 1 Park M. 1 Kim J.-H. 2 Kim M.-H. 2 Yoon S.-C. 2 Department of Atmospheric Sciences, Yonsei University, Seoul, South Korea School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea 26 08 2014 14 16 8763 8779 Copyright: © 2014 J. H. Kim et al. 2014 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://acp.copernicus.org/articles/14/8763/2014/acp-14-8763-2014.html The full text article is available as a PDF file from https://acp.copernicus.org/articles/14/8763/2014/acp-14-8763-2014.pdf

Total number concentrations of particles having a diameter larger than 10 nm (<i>N</i><sub>CN</sub>), cloud condensation nuclei at several supersaturation (<i>S</i>) values (<i>N</i><sub>CCN</sub>) and number size distributions of particles with 10–414 nm diameter were measured in Seoul between 2004 and 2010. Overall average values of <i>N</i><sub>CN</sub> and geometric mean diameter were 17 811 ± 5581 cm<sup>−3</sup> and 48 ± 6 nm. Average <i>N</i><sub>CCN</sub> at 0.4, 0.6 and 0.8% S were 4145 ± 2016, 5323 ± 2453 and 6067 ± 2780 cm<sup>−3</sup> and corresponding <i>N</i><sub>CCN</sub> / <i>N</i><sub>CN</sub> were 0.26 ± 0.11, 0.33 ± 0.11 and 0.37 ± 0.12. There is a clear seasonal variation in aerosol concentration, which seems to be due to the monsoon. <i>N</i><sub>CN</sub> and <i>N</i><sub>CCN</sub> are also found to depend on the volume of traffic and the height of the planetary boundary layer, respectively. <br><br> During aircraft campaigns in 2009 and 2011, <i>N</i><sub>CN</sub> and <i>N</i><sub>CCN</sub> at 0.6% S (<i>N</i><sub>0.6%</sub>) were measured in and around the Korean Peninsula. During the 2011 campaign, the aerosol scattering coefficient was also measured. <i>N</i><sub>CN</sub> and <i>N</i><sub>0.6%</sub> in the lower altitudes were generally higher than at higher altitudes, except for cases when particle formation and growth events were thought to occur at higher altitudes. <i>N</i><sub>CN</sub> and <i>N</i><sub>0.6%</sub> generally show a positive correlation with aerosol scattering coefficients but this correspondence tends to vary with altitude. Occasional instances of low (< 0.3) <i>N</i><sub>0.6%</sub> / <i>N</i><sub>CN</sub> in the boundary layer are demonstrated to be associated with particle formation and growth events. With the support of ground measurements, it is confirmed that a particle formation and growth event did indeed occur over the Yellow Sea on a flight day, and the areal extent of this event is estimated to be greater than 100 km × 450 km. <br><br> With the combination of the current and several relevant previous studies, a composite map of <i>N</i><sub>CN</sub> and <i>N</i><sub>CCN</sub> in and around the Korean Peninsula is produced. Overall, the exhibited concentrations are typical of values measured over polluted regions elsewhere on the globe. Moreover, there is a generally decreasing trend from west to east over the region, implying that the region is constantly under the dominant influence of continental outflow.

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