亚洲夏季风对平流层-对流层物质交换和平流层水汽的影响

In recent years, some researches have suggested that Asian monsoon region is an important channel for tropospheric mass entering the stratosphere. This is because the upper troposphere anticyclone and deep convection activities, which come with the Asian summer monsoon, can lead to the change of stratosphere and troposphere exchange (STE) and stratospheric water vapor. But so far, the details about how the Asian summer monsoon leads to tropospheric mass transport into the stratosphere and its influence have a lot of controversy. The project will diagnose the characteristics and mechanism of STE and stratospheric water vapor changes caused by the Asian summer monsoon based on observations and simulation results, and further investigate quantitative contribution of Asian summer monsoon on STE and stratosphere water vapor trend changes in the past several decades. This will help to understand the main reason for leading the past variations of STE and stratospheric water vapor, so as to improve the prediction of their future changes. The project also use coupled atmospheric chemistry-climate model to perform dynamic-radiation-chemistry coupling simulation. It can study global radiation budget and stratosphere chemical composition changes as a result of stratospheric water vapor changes which caused by the Asian summer monsoon, and also research feedback effect on atmosphere results from the chemical processes changes. Project research focuses on the influence of the Asian summer monsoon to the stratosphere with considering the dynamic-radiation-chemistry feedback in atmosphere. Thus, this project is distinctive and novel.

近年来的研究表明，亚洲季风区是对流层物质进入平流层的一个重要通道，与亚洲夏季风伴随的上对流层反气旋和深对流活动可以导致平流层-对流层物质交换(STE)以及平流层水汽的变化。但是到目前为止，亚洲夏季风调节STE的细节以及其对STE的影响程度还有很大争议。本项目拟从资料分析入手结合大气环流模式模拟结果，诊断亚洲夏季风引起的STE和平流层水汽的变化、特征和机制，并进一步给出亚洲夏季风对STE和平流层水汽趋势变化的定量贡献，这将有助于甄别过去几十年导致亚洲季风区乃至全球STE和平流层水汽变化的主要因子。项目还利用耦合的大气化学气候模式，进行大气化学-动力-辐射耦合的模拟试验，研究由亚洲夏季风造成的平流层水汽变化引起的全球辐射收支和平流层化学成分变化，以及其化学变化对大气的反馈作用。项目研究聚焦于亚洲夏季风对平流层的影响并考虑了化学-动力-辐射过程的相互反馈，具有特色和创新。

项目经过3年的执行期，发表6篇学术论文(SCI 4篇)，在项目的支持下申请人：从助理研究员职称升为副教授，获得2016年谢义炳青年科技奖（省部级），参加国际会议并做口头报告5次，参与组织国际会议3次。取得的成果达到项目考核要求和预期目标。主要学术成果包括：发现由于亚洲夏季风的传输作用，进入平流层的气溶胶大多数来源于东南亚和西南亚，并对全球不同区域排放的物质进去平流层的比例得到了定量化结论；提出暖池扩张造成了过去30年对流层顶的变冷，第二类ENSO活动对对流层顶温度年际变化有重要的贡献；揭示80年代后第二类ENSO是调控热带臭氧年际变化最重要的因子，第二类ENSO对全球臭氧的影响比经典ENSO和QBO的作用还大。