Shipborne observations reveal contrasting Arctic marine, Arctic terrestrial and Pacific marine aerosol properties

• Main Authors: Park, Jiyeon, Dall’Osto, Manuel, Park, Kihong, Gim, Yeontae, Kang, Hyo Jin, Jang, Eunho, Park, Ki-Tae, Park, Minsu, Yum, Seong Soo, Jung, Jinyoung, Lee, Bang Yong, Yoon, Young Jun
• Format: Text
• Language: English
• Published: 2019
• Subjects: Arctic; Arctic Ocean; Breaker; Pacific; Sea ice; Tundra
• Online Access: https://doi.org/10.5194/acp-2019-1076; https://www.atmos-chem-phys-discuss.net/acp-2019-1076/

There are few shipborne observations addressing the factors influencing the relationships of the formation and growth of aerosol particles with cloud condensation nuclei (CCN) in remote marine environments. In this study, the physical properties of aerosol particles throughout the Arctic Ocean and Pacific Ocean were measured aboard the Korean ice breaker R/V Araon during the summer of 2017 for 25 days. A number of New Particle Formation (NPF) events and growth were frequently observed in both Arctic terrestrial and Arctic marine air masses. By striking contrast, NPF events were not detected in Pacific marine air masses. Three major aerosol categories are therefore discussed: (1) Arctic marine (aerosol number concentration CN 2.5 : 413 ± 442 cm −3 ), (2) Arctic terrestrial (CN 2.5 : 1622 ± 1450 cm −3 ) and (3) Pacific marine (CN 2.5 : 397 ± 185 cm −3 ), following air mass back trajectory analysis. A major conclusion of this study is that not only that the Arctic Ocean is a major source of secondary aerosol formation relative to the Pacific Ocean; but also that open ocean sympagic and terrestrial influenced coastal ecosystems both contribute to shape aerosol size distributions. We suggest that terrestrial ecosystems - including river outflows and tundra - strongly affects aerosol emissions in the Arctic coastal areas, possibly more than anthropogenic Arctic emissions. The increased river discharge, tundra emissions and melting sea ice should be considered in future Arctic atmospheric composition and climate simulations. The average CCN concentrations at a supersaturation ratios of 0.4 % were 35 ± 40 cm −3 , 71 ± 47 cm −3 , and 204 ± 87 cm −3 for Arctic marine, Arctic terrestrial, and Pacific marine aerosol categories, respectively. Our results aim to help to evaluate how anthropogenic and natural atmospheric sources and processes affect the aerosol composition and cloud properties.