Enhanced modern carbon and biogenic organic tracers in Northeast Asian aerosols during spring/summer

Abstract

[1] To better understand the organic aerosol (OA) sources and formation processes in Northeast Asia, we studied atmospheric aerosol (total suspended particulate matter (TSP)) samples collected from Sapporo, northern Japan over 1 year period for the measurement of radiocarbon ( 14 C) in aerosol total carbon (TC) and water-soluble organic carbon (WSOC). We also measured various organic tracers and carbonaceous components: organic carbon (OC), WSOC, and elemental carbon (EC). We found that the percent modern carbon (pMC) in TC and WSOC increased during spring/summer with maximum (85% and 117%, respectively) in May. The temporal variations of pMC in WSOC and TC showed a good agreement with changes in the contributions of biogenic OA tracers to OC and WSOC. We also found that emissions of pollen in spring and fungal spores from soil in summer/autumn as well as secondary OA formation from biogenic VOCs (BVOCs) in summer/autumn are responsible for the enhanced pMC. Although emissions from biomass burning are significant in winter, enhanced fossil fuel combustion lowers the pMC in WSOC and TC. Throughout the year, modern carbon is more enriched in WSOC fraction than in TC, indicating that WSOC is more associated with biological activity. This study warrants a need to reconcile the atmospheric models, considering seasonal differences in BVOC emissions, particularly in temperate regions, in estimating secondary OA budget and its climatic impacts.Citation: Pavuluri, C. M., K. Kawamura, M. Uchida, M. Kondo, and P. Fu (2013), Enhanced modern carbon and biogenic organic tracers in Northeast Asian aerosols during spring/summer,

Water-soluble organic carbon aerosols during a full New Delhi winter: Isotope-based source apportionment and optical properties

“…Radiocarbon (Δ 14 C) has recently been shown to be a powerful technique for differentiating biomass versus " 14 C-dead" fossil sources for different components of Asian carbonaceous aerosols [e.g., Gustafsson et al, 2009;Sheesley et al, 2012;Kirillova et al, 2013;Chen et al, 2013;Pavuluri et al, 2013]. In addition, analysis of the stable carbon isotopes ( 13 C/ 12 C) provides additional information regarding sources and atmospheric processing.…”

Anthropogenic and biogenic organic compounds in summertime fine aerosols (PM2.5) in Beijing, China

“…Generally, organic particles are comprised of primary organic aerosols (POA) and secondary organic aerosols (SOA). POA are directly emitted from sources such as higher plants, soil dust, biomass and fossil fuel burning (Simoneit et al, 1999;de Gouw and Jimenez, 2009;Chen et al, 2013;Pavuluri et al, 2013), while SOA are formed by the oxidation of gas-phase precursors in situ or through long-range transport in the atmosphere (Hallquist et al, 2009;Kundu et al, 2010;Aggarwal et al, 2013).…”

“…Biomass burning is a significant source of atmospheric gases and particles on a regional to global scale (Simoneit et al, 1999;Andreae and Merlet, 2001;Engling et al, 2006;Chen et al, 2013;Pavuluri et al, 2013). Particles derived by biomass burning can influence the global climate by absorbing radiation and acting as cloud condensation nuclei (CCN) (Mochida and Kawamura, 2004).…”

Hygroscopic properties of newly formed ultrafine particles at an urban site surrounded by deciduous forest (Sapporo, northern Japan) during the summer of 2011

“…To better understand the effects of biogenic organic emissions on NPF and the subsequent growth mechanism in urban Sapporo, it will be necessary to quantify the proportions of particulate organic aerosols derived from anthropogenic and biogenic sources. These proportions can be determined by measuring radiocarbon and biogenic SOA tracers in sub-µm particles (Pavuluri et al, 2013). Further investigations of diel variations in biogenic SOA tracers and the radiocarbon isotopic ratios of nucleated particles will be necessary if we are to develop a better understanding of the interaction between biogenic and anthropogenic emissions and their effects on NPF, and the subsequent growth of freshly nucleated particles.…”

“…g(85 %) Aitken at dry D p = 100 nm of the Aitken mode particles were slightly higher than those of newly formed nucleation mode particles ( Table 1), suggesting that the growth of freshly formed nucleation mode particles to the Aitken mode size can be subjected to condensation of not only low-volatility organic vapors but also water-soluble inorganic species. Pavuluri et al (2013) measured radiocarbon in the WSOC fraction of the aerosols collected at the same site. They found that, during the summer of 2010, about 88 % of the WSOC consisted of modern carbon.…”