青藏高原调控区域能量过程和全球气候的机理

本文总结了中国国家自然科学基金委重点项目“青藏高原调控区域能量过程及其影响机理”的研究进展。着重阐明了春夏季伊朗高原和青藏高原(TIP)地表热通量特征及变化原因、TIP上空独特的水汽、云宏观和微观垂直结构,以及降水和云辐射效应;在夏季两个高原地区的感热加热存在相互影响和反馈,形成观测到的加热与大气垂直环流之间的准平衡耦合系统,由此提出了TIP系统(TIPS)的概念;项目还从天文和水文的角度佐证了TIPS对亚洲夏季风的影响,揭示TIPS导致上对流层暖、下平流层冷的南亚高压的形成机理及TIPS影响北半球环流和印度洋海气相互作用的物理过程;揭示TIPS系统对南亚高压年际变化的影响,提出高原位涡强迫激发中国东部激烈天气过程的一种新机制。此外还揭示了CMIP5模式对高原表面温度模拟存在冷偏差的原因和其中的物理过程,这是大气环流与冰雪反照率的动力耦合的结果。

Physics of the control of the Tibetan Plateau on regional energetic processes and global climate

This paper is the outcome of the research on the way Tibetan Plateau(TP) regulates regional energetic processes and global climate,which is a key project sponsored by NSFC.The results can be summarized as follows.The concept of Tibetan-Iranian Plateau coupling system(TIPS) was proposed,which was characterized by a unique vertical motion over the Asian subtropical monsoon region.The TIPS was formed by surface sensible heating of the Iranian Plateau(IP) and TP as well as the interaction between them.Studies revealed the variability surface heat flux in TIPs and a unique cloud-precipitation-radiation structure over TP.The influence of TIPS on Asian summer monsoon,in view of astronomical and hydrological perspectives,was verified.Studies clarified the effect of TIPs on South Asian High,which led to warm upper troposphere and cool lower stratosphere.Their influences on northern hemisphere circulation,Indian Ocean air-sea interaction and the inter-annual variability of South Asian High were also explored.A new mechanism was proposed on how the plateau forced to trigger intense weather events in eastern China.The studies also revealed the physical proess of the cold surface temperature bias in CMIP5 models,which was a result of dynamical coupling between atmospheric circulation and snow albedo.