Seasonal variations of biogenic secondary organic aerosol tracers in Cape Hedo, Okinawa

摘要: Abstract Secondary organic aerosol (SOA) substantially contributes to particulate matter affecting the regional and global air quality climate. Total suspended particle (TSP) samples were collected in October 2009 February 2012 on a weekly basis at Cape Hedo, Okinawa, Japan western North Pacific Rim, an outflow region of Asian aerosols precursors. The TSP analyzed for SOA tracers derived from biogenic volatile compounds (BVOCs). isoprene-SOA showed maximum summer (2.12 ± 2.02 ng m−3) minimum winter (1.16 ± 0.92 ng m−3). This seasonality is mainly controlled by isoprene emission local subtropical forest, followed scale surrounding seas long-range transported masses. monoterpene-SOA peaked March (3.38 ± 2.03 ng m−3) (2.95 ± 1.62 ng m−3). In contrast, sesquiterpene-SOA tracer, β-caryophyllinic acid, (1.63 ± 1.18 ng m−3) (0.20 ± 0.46 ng m−3). variations monoterpene- are likely related continental oxidation products BVOC. Using tracer-based method, we estimated total SOC 0.25–157 ng m−3 (mean 35.8 ng m−3) that accounts 0.01–9.8% 2.7%) carbon. Our study suggests formation Rim involved with not only but also emissions atmospheric transport.