青藏高原深对流对平流层水汽的影响及其全球气候效应研究

青藏高原由于其高大地形和夏季强热源的作用，在平流层-对流层物质交换中具有重要贡献。目前，青藏高原深对流活动对平流层水汽的影响及其相关的内在物理机制还不是很清楚。本项目将利用再分析资料，结合多源卫星资料，研究平流层水汽的多尺度精细化时空演变特征，分析比较青藏高原地区平流层水汽与亚洲季风区及同纬度地区的差异。采用高分辨率拉格朗日轨迹模式，计算分析平流层水汽的来源。通过诊断分析，结合数值模拟实验，探讨青藏高原深对流活动对平流层水汽输送的作用过程和内在机理。进一步计算分析青藏高原区域深对流发生时对流层-平流层水汽输送通量，定量评估青藏高原地区深对流活动对平流层水汽变化的贡献。最后通过数值模拟实验，揭示平流层水汽变化的全球气候效应。项目研究成果将为进一步研究平流层-对流层水汽交换及其导致的全球气候环境效应提供事实依据和物理基础。

Tibetan Plateau has a great impact on the atmospheric circulation owing to its giant terrain and strong summertime heat source, and plays an important role in the stratosphere-troposphere exchange (STE). So far, a comprehensive understanding of the deep convective transportation of water vapor over the Tibetan Plateau into the stratosphere and its mechanism is still pending. Using reanalysis data and multi satellite products, this project will first investigate the multi fine-scale spatial-temporal change of stratospheric water vapor, comparing the stratospheric water vapor over the Tibetan Plateau with that over the Asian summer monsoon region and other regions in similar latitudes. The source of stratospheric water vapor is further studied by using a high-resolution airflow trajectory model based on the Lagrangian method. With diagnosis and numerical simulation, transport process of water vapor into the stratosphere by deep convection over the Tibetan Plateau and its dynamical mechanism are also discussed in this project. Specifically, this project will calculate the flux of water vapor transport into the stratosphere caused by deep convections over the Tibetan Plateau, and quantify the contribution of the deep convection over the Tibetan Plateau on stratospheric water vapor variations. Finally, through numerical simulations, this project will unveil the global climatic impacts of stratospheric water vapor variations modulated by deep convections over the Tibetan Plateau. The results of this project could provide fundamental fact and physical understanding for further studies on the STE of water vapor and its global climatic impacts.