夏季青藏高原对流层—平流层交换过程及其气候效应的若干问题
Summertime Stratosphere-Troposphere Exchange over the Tibetan Plateau and Its Climatic Impact
中文摘要：
亚洲是目前世界上经济发展最快的地区，其所带来的区域气候环境问题以及对全球气候环境的可能影响成为当前科学界关注的一个重要课题。一些研究表明，夏季亚洲季风区是边界层大气成分（包括污染物）进入全球平流层的一个重要通道，其中青藏高原由于高大地形的作用而具有重要的地位。从以下几个方面介绍了研究进展及存在的问题：夏季亚洲季风区上对流层/下平流层（UTLS）大气成分及对流层顶气溶胶层的分布特征、卷云及深对流活动特征、夏季南亚高压反气旋环流特征及其对大气成分分布的作用。指出南亚高压反气旋控制区不仅是对流层示踪物的高值区和平流层示踪物的低值区，同时也是气溶胶和卷云覆盖率的大值区，因而是全球比较特殊的地区，从而可以进一步通过大气辐射、微物理、异相化学等过程对区域甚至全球气候环境产生重要影响。比较了亚洲季风区与北美季风区大气成分在UTLS区域分布的异同，讨论了深对流快速输送和大尺度缓慢输送这两种不同尺度过程在大气成分分布的可能作用，尤其对于不同大气成分输送作用的差异，并讨论了南亚高压两种不同模态对UTLS区域大气成分分布的重要作用。最后提出了未来青藏高原对流层—平流层相互作用及其气候效应研究中需要关注的一些关键科学问题。
中文关键词：
平流层—对流层交换，青藏高原，亚洲夏季风，南亚高压，深对流，大气化学
KeyWords：
stratosphere-troposphere exchange, Tibetan Plateau, Asian summer monsoon, South Asia high, deep convection, atmospheric chemistry
Abstract：
Currently, Asia is the world’s fastest growing economic region, which will lead to regional and even global climatic and environmental issues, and these issues are becoming an important topic of concern for the scientific community. Some studies indicate that the Asian summer monsoon region provides a key pathway for the boundary layer species transport into the global stratosphere, in which the Tibetan Plateau plays an important role due to its tall and huge terrain. In this review, a few key scientific aspects and related issues are discussed as follows: atmospheric composition distribution in the upper troposphere and lower stratosphere (UTLS), tropopause aerosol layer, cirrus and deep convection activity over the Asian summer monsoon region, and variation of South Asia high and its impact on UTLS species distribution. It is pointed out that the region controlled by the Asian summer monsoon anticyclone is special in the boreal summer for its enchanced troposheric tracers, aerosol, and cirrus fraction, and dehanced stratospheric tracers, which will have an important impact on regional and even global climate and environment through atmospheric radiation, microphysical and out-of-phase chemical processes. Inter-comparison is conducted between the Asian summer monsoon and the North American summer monsoon on the distribution of various species in the UTLS region, and the respective transportation roles of deep convection activity and large-scale circulation are discussed in determining the distribution of atmospheric species, particularly the variance on different species. Finally, a few critical scientific topics are put forward for future investigation on the stratosphere-troposphere interaction over the Tibetan Plateau and its impact on climate and environment.