Polycyclic aromatic hydrocarbons (PAHs) and their nitrated and oxygenated derivatives in the Arctic boundary layer: Seasonal trends and local anthropogenic influence

A total of 22 polycyclic aromatic hydrocarbons(PAHs), 29 oxy-PAHs, and 35 nitro-PAHs (polycyclic aro-matic compounds, PACs) were measured in gaseous andparticulate phases in the ambient air of Longyearbyen, themost populated settlement in Svalbard, the European Arc-tic. The sampling campaign started in the polar night inNovember 2017 and lasted for 8 months until June 2018,when a light cycle reached a sunlit period with no night.The transport regimes of the near-surface, potentially pol-luted air masses from midlatitudes to the Arctic and the polarboundary layer meteorology were studied. The data analysisshowed the observed winter PAC levels were mainly influ-enced by the lower-latitude sources in northwestern Eurasia,while local emissions dominated in spring and summer. Thehighest PAC concentrations observed in spring, with PAHconcentrations a factor of 30 higher compared to the mea-surements at the closest background station in Svalbard (Zep-pelin, 115 km distance from Longyearbyen), were attributedto local snowmobile-driving emissions. The lowest PAC concentrations were expected in summer due to enhanced photochemical degradation under the 24 h midnight sun conditions and inhibited long-range atmospheric transport. In contrast, the measured summer concentrations were notably higher than those in winter due to the harbour (ship) emissions.publishedVersio