夏季亚洲季风区对流层大气向平流层输送过程的研究

Asian summer monsoon (ASM) is a key pathway for the tropospheric water vapor and pollutants transporting into the global stratosphere and these chemical species will have great impact on stratospheric ozone layer and global climate via microphysics, chemistry and radiation processes, which is a hot topic for international scientific community. Tibetan Plateau has a great impact on the atmospheric circulation owing to its giant terrain and strong summertime heat source, and takes an important role in the stratosphere-troposphere exchange. Currently, there are many uncertainties in the understanding the vertical distribution and variation of chemical species in the upper troposphere and lower stratosphere (UTLS) during the ASM, stratosphere-troposphere exchange processes and its contribution to the budget of chemical species in the global stratosphere, among which, lack of chemical species measurement (particularly in situ observation) is a critical limitation. In this project, combination sounding of water vapor, ozone and particle will be conducted during the ASM as a priority task. The spatial distribution and variability of species in the UTLS will be analyzed by investigate the sounding data combined with satellite product. Numerical simulation and diagnosis will be conducted to explore the transport processes during the tropospheric pollutants into stratosphere. Finally, the contribution of stratosphere-troposphere exchange during the ASM will be assessed in the budget of species in the global stratosphere. These studies will provide evidence and physical bases for further investigation of the global climate effect of the ASM stratosphere-troposphere exchange.

夏季亚洲季风区（ASM）是对流层大气成分进入全球平流层的一个重要通道，这些物质通过化学、微物理和辐射过程对臭氧层和全球气候具有重要影响，因而成为科学界关注的热点问题；青藏高原，由于其高大地形和夏季强热源对大气环流的强烈作用，而在平流层-对流层大气物质交换中具有重要贡献。目前关于ASM上对流层/下平流层（UTLS）大气结构及变化特征、平流层-对流层交换过程与机理以及对全球平流层大气收支贡献的认识方面，主要基于卫星观测和数值模拟，具有很大的不确定性，其中该区域大气成分观测资料的不足是一个重要的制约因素。本项目拟开展ASM水汽-臭氧-粒子联合探测试验，结合卫星观测资料分析ASM-UTLS大气成分结构，通过个例模拟和诊断分析探索ASM对流层污染物向平流层的输送过程和机理，定量评估ASM在全球平流层大气成分收支中的贡献。为进一步研究ASM平流层-对流层交换的全球气候环境效应提供事实依据和物理基础。

夏季亚洲季风区（ASM）是对流层大气成分进入全球平流层的一个重要通道，这些物质通过化学、微物理和辐射过程对臭氧层和全球气候具有重要影响，因而成为科学界关注的热点问题；青藏高原，由于其高大地形和夏季强热源对大气环流的强烈作用，而在平流层-对流层大气物质交换中具有重要贡献。目前关于ASM上对流层/下平流层（UTLS）大气结构及变化特征、平流层-对流层交换过程与机理以及对全球平流层大气收支贡献的认识方面，主要基于卫星观测和数值模拟，具有很大的不确定性，其中该区域大气成分观测资料的不足是一个重要的制约因素。本项目联合国内外有关科研团队在昆明、拉萨等站开展臭氧、水汽、粒子联合探空观测实验，获取了大量有重要物理意义的原位观测数据。结合卫星资料，利用轨迹模式和中尺度模式开展了夏季亚洲季风区对流层-平流层大气物质交换过程的研究，揭示了一些重要的交换机里，尤其在亚洲对流层顶气溶胶层研究方面取得了重要进展，引起了国内外的重要关注。