Organic molecular composition of marine aerosols over the Arctic Ocean in summer: contributions of primary emission and secondary aerosol formation

Abstract

Abstract. Organic molecular composition of marine aerosol samples collected during the MALINA cruise in the Arctic Ocean was investigated by gas chromatography/mass spectrometry. More than 110 individual organic compounds were determined in the samples and were grouped into different compound classes based on the functionality and sources. The concentrations of total quantified organics ranged from 7.3 to 185 ng m −3 (mean 47.6 ng m −3 ), accounting for 1.8-11.0 % (4.8 %) of organic carbon in the marine aerosols. Primary saccharides were found to be dominant organic compound class, followed by secondary organic aerosol (SOA) tracers formed from the oxidation of biogenic volatile organic compounds (VOCs) such as isoprene, α-pinene and β-caryophyllene. Mannitol, the specific tracer for airborne fungal spores, was detected as the most abundant organic species in the samples with a concentration range of 0.052-53.3 ng m −3 (9.2 ng m −3 ), followed by glucose, arabitol, and the isoprene oxidation products of 2-methyltetrols. Biomass burning tracers such as levoglucosan are evident in all samples with trace levels. On the basis of the tracer-based method for the estimation of fungal-spore OC and biogenic secondary organic carbon (SOC), we estimate that an average of 10.7 % (up to 26.2 %) of the OC in the marine aerosols was due to the contribution of fungal spores, followed by the contribution of isoprene SOC (mean 3.8 %) and α-pinene SOC (2.9 %). In contrast, only 0.19 % of the OC was due to the photooxidation of β-caryophyllene. This study indicates that primary organic aerosols from biogenic emissions, both from long-range transport of mid-latitude aerosols and from sea-to-air emission of marine organics, as well as secondary organic aerosols formed from the photooxidation of biogenic VOCs are important factors controlling the organic chemical composition of marine aerosols in the Arctic Ocean.

Particulate trimethylamine in the summertime Canadian high Arctic lower troposphere

“…3), providing further evidence for biomass burning as the source of levoglucosan-and K-containing particles. Despite the potential for oxidation of levoglucosan during transport, it has been previously reported as associated with biomass burning aerosol in Arctic regions (Hu et al, 2013;Fu et al, 2013Fu et al, , 2009. Sierau et al (2014) and Gunsch et al (2017) did not report the detection of levoglucosan with SPMS measurements in the summertime Arctic.…”

Processes controlling the annual cycle of Arctic aerosol number and size distributions

“…Growth and loss of particles with diameters smaller than 3 nm are approximated with the Kerminen et al (2004) scheme (evaluated in TOMAS in Y. H. . In our simulations, we do not include NPF by organic vapours such as those arising from the oceans (O'Dowd and de Leeuw, 2007;Fu et al, 2013). Currently, no single nucleation scheme includes contributions from organics, sulfuric acid, bases, and water.…”

Aircraft measurements of polar organic tracer compounds in tropospheric particles (PM<sub>10</sub>) over central China

“…2 and Table 2). These acids have been found in both smoke particles (Oros and Simoneit, 2001;Simoneit, 2002) and ambient aerosols (Simoneit, 2002;Fu et al, 2008Fu et al, , 2013. The opposite seasonal trends of lignin/resin acids and anhydrosugars suggest that they are derived from the burning of different biofuels.…”