气候变化对大气复合污染的影响过程与机制

Atmospheric complex pollution is affected not only by emissions of air pollutants and chemical transformation, but also influenced significantly by ambient meteorological conditions. It is known that many meteorological parameters are changing with global warming. For instance, the wind speed, temperature lapse rate and precipitation in China as well as over the globe have changed significantly as the result of global warming in the last 60 years. These meteorological parameters can affect significantly the level of atmospheric complex pollution. So in this proposal, we propose to study how the atmospheric complex pollution is affected by the meteorological parameters which have been changing with global warming. To our knowledge, although there are a large number of investigations on the effect of air pollutants (such as aerosols) on climate change, there has been no report on the long-term changes of atmospheric complex pollution due to changes of meteorological parameters as the result of global warming. Therefore our proposed research will not only enable us to have an improved understanding of atmospheric complex pollution, but also improve our capability in the development of effective air pollution control strategies. In addition, the proposed research could lead us into the realm of international cutting edge research.

大气复合污染的浓度, 不仅受大气污染物排放与大气化学转化的影响, 也受气象条件的控制, 而气象参数如风速、大气温度垂直梯度及降雨等, 正因全球变暖而发生明显的变化, 这些气象参数对大气复合污染有相当程度的影响, 因此本项目将研究全球变暖有关的气象参数的变化, 及其对大气复合污染的影响。本项目完成后, 将能帮助我们更全面、更深入地了解中国空气质量的长期变化, 进而增强改善中国空气质量的策略。就我们所知, 虽然有大量文献报道大气污染物(如气溶胶)对气候变化的影响, 目前尚没有文献报道从气候变化有关的气象参数变化的角度来研究大气复合污染的长期趋势, 因此研究全球变暖有关的气象参数的变化, 及其对大气复合污染的影响, 既是国际这一领域的学术前沿, 也是我国城市群大气污染联防联控工作急需突破的基础科学问题。

大气复合污染与气候变化间存在着复杂的联系，为把握大气复合污染的长期变化，科学认知大气复合污染长期变化中的天气气候因素和污染排放因素的相对贡献，需要深入研究各种形成大气复合污染的大气成分长期变化、导致大气复合污染的气象条件的长期变化规律，揭示其与气候变化的相互作用过程与机制。本项目基于观测数据，分析了我国四大区域（京津冀、长三角、珠三角和四川盆地）霾污染和气象参数的长期变化趋势，并通过对比清洁日和污染日气象条件的差异，识别出影响区域霾污染的关键气象参数，建立重要气象参数与大尺度大气环流的关系，构建基于观测的统计模型，定量分析气候因子对复合污染的贡献。基于WRF/Chem的敏感性试验，评估了污染物防控措施的效果，提出有效降低复合污染的最佳减排方案。研究发现，气候气象条件对我国重要区域的霾日长期污染有重要作用，该作用可以对污染排放控制效果形成掩蔽效应，必须持续减排克服掩蔽效应。