Organic functional groups in the submicron aerosol at 82.5° N, 62.5° W from 2012 to 2014

• Published in: Atmospheric Chemistry and Physics
• Main Authors: W. R. Leaitch, L. M. Russell, J. Liu, F. Kolonjari, D. Toom, L. Huang, S. Sharma, A. Chivulescu, D. Veber, W. Zhang
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2018
• Subjects: Physics; QC1-999; Chemistry; QD1-999; Arctic
• Online Access: https://doi.org/10.5194/acp-18-3269-2018; https://doaj.org/article/3924ab8d99fa476cac429528608187b8

The first multi-year contributions from organic functional groups to the Arctic submicron aerosol are documented using 126 weekly-integrated samples collected from April 2012 to October 2014 at the Alert Observatory (82.45° N, 62.51° W). Results from the particle transport model FLEXPART, linear regressions among the organic and inorganic components and positive matrix factorization (PMF) enable associations of organic aerosol components with source types and regions. Lower organic mass (OM) concentrations but higher ratios of OM to non-sea-salt sulfate mass concentrations (nss-SO 4 = ) accompany smaller particles during the summer (JJA). Conversely, higher OM but lower OM ∕ nss-SO 4 = accompany larger particles during winter–spring. OM ranges from 7 to 460 ng m −3 , and the study average is 129 ng m −3 . The monthly maximum in OM occurs during May, 1 month after the peak in nss-SO 4 = and 2 months after that of elemental carbon (EC). Winter (DJF), spring (MAM), summer and fall (SON) values of OM ∕ nss-SO 4 = are 26, 28, 107 and 39 %, respectively, and overall about 40 % of the weekly variability in the OM is associated with nss-SO 4 = . Respective study-averaged concentrations of alkane, alcohol, acid, amine and carbonyl groups are 57, 24, 23, 15 and 11 ng m −3 , representing 42, 22, 18, 14 and 5 % of the OM, respectively. Carbonyl groups, detected mostly during spring, may have a connection with snow chemistry. The seasonally highest O ∕ C occurs during winter (0.85) and the lowest O ∕ C is during spring (0.51); increases in O ∕ C are largely due to increases in alcohol groups. During winter, more than 50 % of the alcohol groups are associated with primary marine emissions, consistent with Shaw et al. (2010) and Frossard et al. (2011). A secondary marine connection, rather than a primary source, is suggested for the highest and most persistent O ∕ C observed during the coolest and cleanest summer (2013), when alcohol and acid groups made up 63 % of the OM. A secondary marine source may be a general feature of ...