ИСТИНА

Polar aerosol station “Island Bely” has been established on the Bely Island (Kara Sea) in Western Siberia Arctic where a significant lack of observational data exists. The aim was to perform long-term monitoring of the air pathway of large-scale emission plumes from industrial regions of Eurasia and Siberian wildfires to the Arctic (Popovicheva et al., 2022). High-resolution, long-term light-absorption measurements resulting from ongoing measurements at Island Bely during 2019-2022 are reported here. The focus is to expand on BC inter-annual and seasonal variability over the Arctic measured at multiple polar stations.For the period between October 2019 and September 2020, BC measurements and modelling at Bely were complemented with those taken onboard the Polarstern RV during the MOSAiC expedition in Central Arctic. The highest BC concentrations at Island Bely (640 ng/m3) was recorded on 19.12.2019 with the biggest contribution to be from GF (44%) and DOM (21%). The highest pollution from GF sector (42%) was observed in the North Pole on 19.02.2020 when air masses arrived from the oil and gas extraction fields of the Western Siberia (Fig.1), while measured BC approached 365 ng/m3. At that time, air arriving to Bely Island was transported from Europe bringing only 63 ng/m3 of BC. Pollution episodes from both locations show that the spatiotemporal distributions of Arctic BC are highly variable, mainly due to different transport of the main anthropogenic source emissions. FLEXPART represents measured BC at Island Bely well because its location closer to the source regions, which in turn assists our understanding of aerosol pollution in the Arctic.