青藏高原夏季UTLS异相化学对臭氧低谷形成的机制研究

Studies with the Antarctic ozone hole, Arctic ozone depletion and the ozone valley over the Tibetan Plateau under different environmental conditions, have enriched the knowledge on mechanism and variability of stratospheric ozone（protection for earth）. There have been many of research work on the dynamical mechanism of the ozone valley over the Tibetan Plateau. The main viewpoints on the dynamic effect are, the deep convection in Asian monsoon region can convey air with lower ozone concentration upward the upper troposphere and lower stratosphere (UTLS), then dilute the ozone concentration in that region. In addition, due to the trapping effect the South Asia high, ozone concentration is lower than that on the same height of surrounding areas. So far there is less idea about the role of its chemical processes. In recent years, with satellite observations aerosol particles and cirrus clouds were found in UTLS, which provide the reaction interface for heterogeneous chemical. Therefore, this proposal aims to develop a heterogeneous ozone photochemical box model to discuss the effect of heterogeneous atmospheric chemistry and chemical process of the lower stratosphere ozone distribution over the Tibetan Plateau with a variety of satellite data. It will hoped to look forward some new ideas and results in understanding the chemical mechanism by ozone valley on interaction between stratosphere and troposphere and mutual adaptation to global change.

对南极“臭氧洞”、北极冬季臭氧损耗以及青藏高原夏季臭氧低谷这些在不同环境条件下发生的臭氧损耗事件的研究，丰富了科学家对平流层臭氧（地球生物的保护伞）的变化和机理的认识。对于青藏高原夏季臭氧低谷现象的形成机制，目前其动力作用的主要观点是，亚洲季风区的深对流将低层低臭氧浓度空气输送至上对流层-下平流层（UTLS）以及南亚高压的围困作用。然而，关于其化学过程的作用目前的认识尚不深入。近几年的卫星观测表明，在UTLS区域存在气溶胶、卷云等粒子，这些粒子为异相化学反应提供了很好的反应介面。因此，本项目拟建立并发展青藏高原UTLS区域平流层臭氧非均相光化学系统，并结合多种卫星资料，讨论非均相大气化学过程对高原上空的平流层下层臭氧变化的影响，探讨异相化学反应在青藏高原夏季臭氧低谷形成中的作用，可以期待本项目将对青藏高原对流层-平流层大气之间的相互作用和相互适应提供一些新的研究思路和认识。

亚洲对流层顶气溶胶层的存在及其气溶胶异相化学对青藏高原夏季臭氧低谷的影响，这一科学问题一直得到持续的关注。对于青藏高原夏季臭氧低谷动力学成因已有一些讨论，但对于其化学成因特别是非均相化学过程目前的认识尚不全面。本项目利用表征青藏高原平流层臭氧异相化学系统的箱模式，结合卫星遥感资料，探讨青藏高原UTLS区域异相化学对夏季臭氧低谷形成的化学作用。本项目的研究内容是青藏高原平流层与对流层大气相互作用所关注的前沿科学问题，其结果有助于认识青藏高原对流层与平流层大气臭氧变化以及非均相化学的影响作用。