亚洲夏季风反气旋是北半球夏季上对流层和下平流层（UTLS）区域主要的大气环流形式，与之相关的物理化学和动力输送过程对对流层-平流层物质输送以及全球大气化学和气候变化有重要影响。近年来的研究发现，亚洲夏季风期间亚洲边界层内的污染物会通过深对流输送至反气旋中，反气旋中的污染气团具有臭氧贫瘠、臭氧前体物和挥发性含卤有机物富有的化学特征。而这些富集的气态污染物如何影响反气旋中臭氧的化学收支，目前尚不清楚。本项目拟采用平流层和对流层过程全耦合的全球大气化学环流模式EMAC，结合各种卫星产品、飞机航测、青藏高原探空和地基遥感观测资料，研究亚洲夏季风反气旋中反应性气体的来源、时空分布特征和各种催化反应循环对臭氧化学收支的影响。项目研究有助于进一步揭示UTLS区域臭氧的化学输送和变化机制，加深平流层-对流层相互作用机理的认识，推动我国在亚洲季风和全球大气化学方面的研究进展。

The Asian summer monsoon anticyclone (ASMA) is a dominated atmospheric circulation pattern in the upper troposphere and lower stratosphere (UTLS) of the Northern Hemisphere. The physical, chemical and dynamic processes associate with ASMA may have a large influence on the transport of tropospheric masses to the stratosphere, and thus global atmospheric chemistry and climate change. Recent studies have shown that Asian pollutants can be transported to the anticyclone through deep convection and trapped there during the Asian summer monsoon. Compared to the outside of ASMA, air masses in the ASMA generally have a chemical feature of being poor in ozone and rich in its precursors as well as volatile halocarbons. However, how these accumulated gaseous pollutants affect the chemical budget of ozone within the ASMS is still unclear. With this proposal, we plan to use an atmospheric chemistry-general circulation model (EMAC) with coupled stratosphere and troposphere processes, together with various satellite product, aircraft measurement and ground-based remote sensing observational data, to investigate the temporal-spatial distributions of reactive trace gases, the sources and aging process of air masses, and the effect of catalytic reaction cycles on the ozone chemical budget within the ASMA. The proposed study will be helpful for revealing the chemical transport and variation mechanism of ozone in the UTLS and for further understanding the troposphere-stratosphere interactions during Asian summer monsoon.