title: Fossil and Nonfossil Sources of Organic and Elemental Carbon Aerosols in the Outflow from Northeast China.
abstract: Source quantification of carbonaceous aerosols in the Chinese outflow regions still remains uncertain despite their high mass concentrations. Here, we unambiguously quantified fossil and nonfossil contributions to elemental carbon (EC) and organic carbon (OC) of total suspended particles (TSP) from a regional receptor site in the outflow of Northeast China using radiocarbon measurement. OC and EC concentrations were lower in summer, representing mainly marine air, than in other seasons, when air masses mostly traveled over continental regions in Mongolia and northeast China. The annual-mean contribution from fossil-fuel combustion to EC was 76 ± 11% (0.1-1.3 μg m(-3)). The remaining 24 ± 11% (0.03-0.42 μg m(-3)) was attributed to biomass burning, with slightly higher contribution in the cold period (∼31%) compared to the warm period (∼21%) because of enhanced emissions from regional biomass combustion sources in China. OC was generally dominated by nonfossil sources, with an annual average of 66 ± 11% (0.5-2.8 μg m(-3)), approximately half of which was apportioned to primary biomass-burning sources (34 ± 6%). In winter, OC almost equally originated from primary OC (POC) emissions and secondary OC (SOC) formation from fossil fuel and biomass-burning sources. In contrast, summertime OC was dominated by primary biogenic emissions as well as secondary production from biogenic and biomass-burning sources, but fossil-derived SOC was the smallest contributor. Distinction of POC and SOC was performed using primary POC-to-EC emission ratios separated for fossil and nonfossil emissions.
authors.affiliation: Yale-NUIST Center on Atmospheric Environment, Nanjing University of Information Science and Technology , Nanjing 10044, China.|Institute of Low-Temperature Science, Hokkaido University , N19 W08, Kita-ku, Sapporo 060-0819, Japan.
authors.forename: Yan-Lin
authors.initials: YL
authors.lastname: Zhang
authors.affiliation: Institute of Low-Temperature Science, Hokkaido University , N19 W08, Kita-ku, Sapporo 060-0819, Japan.
authors.forename: Kimitaka
authors.initials: K
authors.lastname: Kawamura
authors.affiliation: Department of Chemistry and Biochemistry & Oeschger Centre for Climate Change Research, University of Bern , Bern 3012, Switzerland.|Paul Scherrer Institute (PSI) , Villigen-PSI 5232, Switzerland.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Agrios
authors.affiliation: Department of Earth and Environmental Sciences, Korea University , Seoul 136-701, South Korea.
authors.forename: Meehye
authors.initials: M
authors.lastname: Lee
authors.affiliation: Department of Chemistry and Biochemistry & Oeschger Centre for Climate Change Research, University of Bern , Bern 3012, Switzerland.
authors.forename: Gary
authors.initials: G
authors.lastname: Salazar
authors.affiliation: Department of Chemistry and Biochemistry & Oeschger Centre for Climate Change Research, University of Bern , Bern 3012, Switzerland.
authors.forename: Sönke
authors.initials: S
authors.lastname: Szidat
mesh_terms: D000336:Aerosols; D000393:Air Pollutants; D002244:Carbon; D002681:China; D004784:Environmental Monitoring; D005580:Fossils; D052638:Particulate Matter; D012621:Seasons
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D052638:Particulate Matter; D002244:Carbon