[A-AS04] Atmospheric Chemistry

[AAS04-P03] Investigation of Atmospheric Aerosol Particles and gases by R/V Mirai cruise over the Arctic Ocean on 2017

*Fumikazu Taketani¹, Saki Kato^1,2, Takuma Miyakawa¹, Masayuki Takigawa¹, Masahiro Yamaguchi¹, Hisahiro Takashima^1,2, Petr Mordovskoi¹, Yugo Kanaya¹ (1.Japan Agency for Marine-Earth Science and Technology, 2.Fukuoka University)

Keywords:Black Carbon, Arctic Ocean, Ship-based Observation

Atmospheric aerosol particles play an important role in Arctic climate through the absorbing and scattering of solar radiation. Also, the deposition of light-absorbing particles on the surface reduces the Earth’s albedo and accelerates snow/ice melting by absorbing the sunlight. However, the observational information has been still insufficient to assess their contribution over the Arctic region. In this study, we conducted the ship-based measurements of marine aerosol particles (black carbon (BC), and fluorescent property) and trace gases (ozone and carbon monoxide) using R/V Mirai during a cruise across the Arctic Ocean and Bering Sea (23 August – 4 October 2017). The measured BC mass concentration over the Arctic Ocean in the latitudinal region > 70°N was an overall mean value of 3.5 ± 2.0 ng/m³ . This value was almost same to the levels recorded during our previous observations in the Arctic cruise on September during 2014 -2016. We captured relatively high BC mass concentration and/or CO mixing ratio events at 4 and 7-12 September 2017. The trajectory and BC property suggested that the source of BC on 4 September could be oil field at north of Alaska. We will present further analysis on the size distribution, BC mixing state, during the cruise in the presentation.