资源环境科技发展态势分析平台

As a case study, the fate of pollutants subjected to long-range transport over northeast Asia was investigated. These pollutants originated as emitted particulate pollutants from Chinese source area, moved across the Yellow Sea (YS), and entered the Korean Peninsula (KP) during the Megacity Air Pollution Studies Seoul (MAPS-Seoul) 2015 aircraft field campaign. The MAPS-Seoul campaign, designed as a precampaign of the Korea-United States Air Quality (KORUS-AQ) campaign, was performed to diagnose the air quality around the KP and YS. Of particular interest during the campaign period was the existence of the elevated mixed layer (EML), the lofted layer of highly concentrated fine aerosols, observed in the marine atmosphere in and around the western coast of the KP. The pollutants within EML identified with the bulk Richardson number of 1.2-6.1, transported longer toward the downwind area than within marine boundary layer. As a result, pollutants emitted from Chinese source areas can cross the YS due to the EML and influence the surface air quality on downstream areas, where the inland boundary layer is sufficiently developed. We also analyzed the vertical distribution of the simulated sulfur dioxide (SO2) and sulfate (SO42-) in the EML over China-YS-KP belt area and found that the concentration of SO4-2 increases through a hygroscopic conversion process as the gas phase precursors move across the YS in an environment full of water vapor. Therefore, the EML makes the transport of the Chinese plume possible, as it passes over the marine boundary layer, entering downwind area over northeast Asia.