New particle formation and growth in relation to vertical mixing and chemical species during ABC-EAREX2005

As a part of ABC-EAREX2005 (Atmospheric Brown Cloud-East Asia Regional Experiment 2005), particle number size distributions, gaseous species, and meteorological parameters were measured at Gosan Superstation (33.17°N, 126.10°E, 70 m ASL) on Jeju Island in South Korea from March 13 to 30, 2005. Four particle formation and growth events that occurred on 14, 19, 25, and 30 March were discussed in detail. They took place on a synoptic scale under a high pressure system with intervals of 5-6 days. New particle formation and growth processes were very sensitive to the level of precursor gases and preexisting particles. SO2 was likely to be the dominant precursor gas. Vertical mixing also played a key role by diluting preexisting particles. The fastest growth event occurred on 25 March with the entrainment of free tropospheric air, which must have been influenced by an anthropogenic plume. The particle growth rates ranged from 1.97 to 5.81 nm h−1 and the condensation sink varied between 1.5 ∙ 10−3 and 8.4 ∙ 10−2 s−1.