Impacts of Siberian Biomass Burning on Organic Aerosols over the North Pacific Ocean and the Arctic: Primary and Secondary Organic Tracers

Abstract

During the 2003 Chinese Arctic Research Expedition (CHINARE2003) from the Bohai Sea to the high Arctic (37°N− 80°N), filter-based particle samples were collected and analyzed for tracers of primary and secondary organic aerosols (SOA) as well as water-soluble organic carbon (WSOC). Biomass burning (BB) tracer levoglucosan had comparatively much higher summertime average levels (476 ± 367pg/m 3 ) during our cruise due to the influence of intense forest fires then in Siberia. On the basis of 5-day back trajectories, samples with air masses passing through Siberia had organic tracers 1.3−4.4 times of those with air masses transporting only over the oceans, suggesting substantial contribution of continental emissions to organic aerosols in the marine atmosphere. SOA tracers from anthropogenic aromatics were negligible or not detected, while those from biogenic terpenenoids were ubiquitously observed with the sum of SOA tracers from isoprene (623 ± 414pg/m 3 ) 1 order of magnitude higher than that from monoterpenes (63 ± 49 pg/m 3 ). 2-Methylglyceric acid as a product of isoprene oxidation under high-NO x conditions was dominant among SOA tracers, implying that these BSOA tracers were not formed over the oceans but mainly transported from the adjacent Siberia where a high-NO x environment could be induced by intense forest fires. The carbon fractions shared by biogenic SOA tracers and levoglucosan in WSOC in our ocean samples were 1−2 orders of magnitude lower than those previously reported in continental samples, BB emissions or chamber simulation samples, largely due to the chemical evolution of organic tracers during transport. As a result of the much faster decline in levels of organic tracers than that of WSOC during transport, the trace-based approach, which could well reconstruct WSOC using biogenic SOA and BB tracers for continental samples, only explained ∼4% of measured WSOC during our expedition if the same tracer-WSOC or tracer-SOC relationships were applied.

Tracing atmospheric transport of soil microorganisms and higher plant waxes in the East Asian outflow to the North Pacific Rim by using hydroxy fatty acids: Year‐round observations at Gosan, Jeju Island

“…Recent studies have documented the impact of mineral dust from East Asian Deserts on the Yellow Sea and South China through long‐range atmospheric transport during the spring [ Tan et al , ]. Likewise, several studies have documented the impact of biomass burning emissions in China and Siberia to the aerosol composition over the North Pacific [ Ding et al , ; Verma et al , ; Zhu et al , ] and the Japanese Islands [ Pavuluri et al , ] during winter and spring, as assessed by the analyses of 14 C and biogenic organic tracers in aerosols. Therefore, a large temporal variability of β ‐ and ω ‐hydroxy FAs over Gosan during spring can be explained by different contributions from Mongolian desert dust and higher plant waxes from Siberia.…”

Spatial distributions of secondary organic aerosols from isoprene, monoterpenes,β-caryophyllene, and aromatics over China during summer

“…Moreover, the compositions of SOA tracers can provide additional information in formation processes and sources. The ratio of 2-methylglyceric acid to 2-methyltetrols has been applied to trace the influence of NO x on SOA I formation [Ding et al, 2013;Lewandowski et al, 2013]. The ratio of 3-hydroxyglutaric acid to 3-methyl-1,2,3-butanetricarboxylic acid can distinguish α-pinene from other monoterpenes [Jaoui et al, 2005;Lewandowski et al, 2013].…”

“…A large-scale survey of SOA tracers can provide a full picture of the spatial distribution, formation mechanisms, and precursor origins of SOA on a continental or global scale. Until the present, largescale observations of SOA tracers have been conducted over the global oceans [Ding et al, 2013;Fu et al, 2011;Hu et al, 2013]. On the continents, field studies are typically performed at several sites within a region [Claeys et al, 2004;Fu et al, 2009;Hu et al, 2008;Lewandowski et al, 2013;von Schneidemesser et al, 2009].…”

Spatial and seasonal variations of secondary organic aerosol from terpenoids over China

“…Large‐scale and long‐term field observations can provide important information on SOA amount, composition, and spatiotemporal distribution, which is vital to constrain models. From regional to global scales, ambient levels of SOA or secondary organic carbon (SOC) have been estimated based on measurements of organic carbon (OC) and elemental carbon [ Hand et al , ; Xin et al , ], water‐soluble OC [ de Gouw et al , ; Ding et al , ], SOA tracers [ Ding et al , ; Fu et al , ], and oxygenated OA by aerosol mass spectrometry [ Zhang et al , ].…”