青藏高原大气动力、热力过程对中国东部大气污染时空变异影响的机理

The Tibetan Plateau (TP), acting as the upstream key sensitive area of the climate and weather in Eastern China, exert a profound impact on its atmospheric circulation and regional air pollution. Precious studies have shown the abnormal and long-lasting distribution of aerosols over the large scale city clusters to the east of TP. Taking the Huabei (Beijing-Tianjin-Hebei) and Huadong (Yangtze River Delta) regions of China as the study areas, this project will explore the influence mechanism of the dynamical effects of the special "down-rolled flow", the impacts "vertical circulation structure" and baffling flow at the lee of TP on aerosol influential domain, as well as the aerosol "convergence zone" and the aerosol transmission tunnel over eastern China. Then, the relationship between the plateau heat source structure and the characteristics of "inversion cover" over eastern China will be explored. This "strong signals" of upper atmospheric temperature anomaly and the frequent low-level temperature inversion during the heavy pollution process will be further revealed. Thereafter, the correlation mechanism between TP’s 3-D dynamical and thermal structures and water vapor transport pattern and aerosol high-humid environmental effects in the east of the magarelief will be explored, and the effects of TP’s atmospheric heat sources changes in different monsoon years on aerosol distribution and the "climate modulations" in the haze weather variation processes over eastern China will also be analyzed. This project plans to investigate the changes of TP’s 3-D dynamical and thermal structures and the combined influence mechanisms of East Asian monsoons on spatiotemporal distribution and variation of air pollution over Eastern China, and it is highly expected to expand the theory of TP effect to the frontier research and application study of atmospheric environment.

青藏高原是我国天气气候的上游敏感区，其对东亚大气环流乃至区域大气污染有重大影响。针对青藏高原东部城市群大范围气溶胶呈异常分布，并呈持续现象，本项目将华北（京津冀）与华东（长三角）为重点研究区域，探讨高原背风坡特殊“垂直环流结构”与大地形绕流、汇流等动力效应对中国东部大气污染过程气溶胶影响域及其“辐合带”、输送通道的影响机制，研究中国东部高原热源结构与大地形东侧大气上层温度距平“逆温盖”相关特征，本项目将揭示此“强信号”特征与低层逆温频发相关机理；探讨青藏高原三维动力、热力结构与大地形东部水汽输送流型，气溶胶高湿环境效应的相关机理，并剖析不同季风年型下青藏高原大气热源变化对中国东部气溶胶分布及霾天气变异过程的“气候调节”作用。本项目拟研究青藏高原动力、热力三维结构变化及其季风活动对大地形东部区域大气污染分布变异的协同影响机理，有望将青藏高原影响理论拓展到大气环境前沿性领域的应用研究之

青藏高原大地形作用是形成中国重大灾害气候格局的关键因子，其动力、热力强迫对中国中东部大气污染产生重要影响。针对青藏高原动力、热力过程对中国中东部大气污染影响机理的重大科学问题，本项目围绕制定的研究内容和研究目标，以京津冀、长三角、四川盆地等为重点研究区域，探讨了青藏高原“背风坡”与大地形动力效应对中国东部大气污染过程的影响；研究了青藏高原动力和热力强迫对中国中东部大气气溶胶时空变化影响；从年代际尺度的视角揭示了高原热力影响我国东部地区霾事件的机理；分析了青藏高原大地形热源与中国东部对流层中层“暖盖”相关关系；研究了青藏高原大地形热力和东亚冬季风协同作用与我国东部大气污染之间的关系：揭示了边界层高度与PM2.5浓度的关系；探寻了青藏高原热、动力异常对四川盆地霾年际变率的影响及其预测信号，开发出大气环境综合资料应用系统和大气污染和排放源反演技术。通过上述研究，深化了青藏高原大地形动力、热力过程与季风活动对中国东部大气环境长期演变协同影响的认知；明确了青藏高原大地形“背风坡”大气流场三维动力结构对中国东部大气污染季节特征及其时空分布变化的影响；给出了青藏高原动力、热力过程对中国东部重点区域重污染天气过程影响的物理概念模型； 寻找出青藏高原热、动力异常对中国东部大气污染年际变率的影响及其预测信号。本项目研究得到的有关青藏高原动力、热力强迫及季风活动对大地形东部地区大气污染时空分布变化的协同影响的机理，为进一步深入研究青藏高原大地形在形成中国重大灾害气候格局中的作用提供了理论基础。