中国大气汞转化关键污染物的浓度变化对其扩散传输的影响研究

中国大量汞排放不仅造成本地的大气汞污染，同时越境传输对周边国家造成影响。大气汞转化关键污染物的浓度变化显著影响其扩散传输和越境污染。而中国人为活动和控制政策使得关键污染物浓度高并且发生了显著的季节和年际变化，这势必会影响中国地区大气汞的扩散传输，然而学界对这个问题仍然知之甚少。本研究将聚焦臭氧（O3）、二氧化氮（NO2）、过氧羟基自由基（HO2）和细颗粒物（PM2.5）这四种大气汞转化关键污染物。在微观化学机理的支撑下，本研究运用大气汞扩散传输模型，模拟各关键污染物组分的浓度变化对中国地区大气汞扩散传输的影响，从化学转化层面揭示污染物组分浓度变化对中国地区大气汞观测浓度季节变异性不明显以及逐年下降趋势等现象的影响机制，评估污染物组分浓度变化对中国地区大气汞本地沉降和越境传输的影响。本研究将为我国促进和优化大气污染协同控制、合理承担国际社会汞减排责任、高效履约《水俣公约》提供理论和方法支持。

Large atmospheric mercury (Hg) emissions in China not only lead to local atmospheric Hg pollution, but also impact on neighboring countries due to transboundary transport. The changing concentrations in key Hg-related air pollutants significantly affect the diffusion, transport and transboundary pollution of atmospheric Hg. Moreover, human activities and control policies in China have resulted in high concentrations of key pollutants and significant seasonal and interannual variations, which is bound to affect the diffusion and transport of atmospheric Hg in China. However, academic communities still know little about this problem. This study will focus on four key Hg-related air pollutants such as ozone (O3), nitrogen dioxide (NO2), peroxyhydroxyl radical (HO2) and fine particulate matter (PM2.5). Under the support of micro chemical mechanism, this study uses atmospheric Hg chemical transport model and simulates the impact of changing concentrations in each key Hg-related air pollutant on the diffusion and transport of atmospheric Hg in China. From the perspective of chemical transformation, this study will reveal the influence mechanism of changing concentrations in air pollutants on the phenomenon of insignificant seasonal variability and significant decreasing trend of observed Hg concentrations in China. Furthermore, this study will evaluate the impact of changing concentrations in air pollutants on local deposition and transboundary transport of atmospheric Hg in China. This study will provide theoretical and methodological support for China to promote and optimize the coordinated control of air pollution, reasonably assume the responsibility for international Hg reductions, and effectively implement the Minamata Convention.