Abstract
ABSTRACT Intensive observation campaigns approximately 1 week long were conducted periodically from March 2010 to November 2015 at Cape Hedo, Okinawa, Japan. The maximum daily mean sulfate aerosol (SO42–) concentrations surpassed 15 µg m–3 in spring 2012. In this study, source apportionment for these high concentrations was conducted using an air quality model with the tagged tracer method, and the main source was identified as volcanoes in March and as anthropogenic emissions from China in April. In March, the prevailing northerly wind transported a volcanic SO2 plume with a low conversion ratio to Cape Hedo. The impacts of 15 volcanoes in Japan were estimated, and a substantial impact from Sakurajima, which accounted for more SO2 than anthropogenic emissions from Japan, was found. Because the model had difficulty capturing the highest concentration, three sensitivity simulations were performed to consider the uncertainty of the volcanic SO2 emission amounts and injection heights, revealing the importance of the injection height in addition to the SO2 emission amount. Throughout April, contributions from anthropogenic emissions from China were found; hence, this source was further divided into 31 provincial scales. Shandong and Jiangsu Provinces, which are the first and seventh largest emission sources in China, respectively, were identified as significant sources at Cape Hedo. These sources showed day-to-day variation in their contributions, and the highest contribution from Shandong Province occurred on April 23, whereas that from Jiangsu Province occurred on April 22.
Highlights
Asian air quality is currently the subject of intense interest due to its regional-to-global impacts (Carmichael et al, 2009)
At Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS), sulfate aerosol (SO42–), which is mainly produced by the oxidation of sulfur dioxide (SO2), was the dominant aerosol component (e.g., Tatsuta et al, 2017), as it is across Japan (Chatani et al, 2018)
We evaluated the sources of SO42– during the high concentration episodes based on an air quality model with the tagged tracer method
Summary
Asian air quality is currently the subject of intense interest due to its regional-to-global impacts (Carmichael et al, 2009). Understanding aerosol transformation processes during long-range transport (LRT) is essential for air quality and regional climate change. An intensive observation campaign has been conducted continuously at Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS), Okinawa, Japan. Air masses are transported to CHAAMS from China, Korea, Japan, Southeast Asia, or the Pacific Ocean depending on the wind pattern. The location of CHAAMS is suitable for capturing the atmospheric pollutants that travel via LRT and has already revealed the behavior of aerosols affected by LRT (Takami et al, 2007; Hatakeyama et al, 2011; Shimada et al, 2015; Shimada et al, 2016; Itahashi et al, 2017a). At CHAAMS, sulfate aerosol (SO42–), which is mainly produced by the oxidation of sulfur dioxide (SO2), was the dominant aerosol component (e.g., Tatsuta et al, 2017), as it is across Japan (Chatani et al, 2018)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
