青藏高原“亚洲水塔”效应和大气水分循环特征  

Effect of the Asian Water Tower over the Qinghai-Tibet Plateau and the characteristics of atmospheric water circulation

作　　者：徐祥德[1] 董李丽 赵阳[1] 王寅钧[1] Xiangde Xu;Lili Dong;Yang Zhao;Yinjun Wang(State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081,China;National Climate Center,China Meteorological Administration,Beijing 100081,China)

机构地区：[1]中国气象科学研究院,灾害天气国家重点实验室,北京100081 [2]国家气候中心,北京100081

出　　处：《科学通报》2019年第27期2830-2841,共12页Chinese Science Bulletin

基　　金：国家重大科学研究计划(2019QZKK0100);国家自然科学基金重大计划(91337000);中国气象科学研究院科技发展基金(2018KJ019);中国气象科学研究院基本科研业务费专项(2018Y008)资助

摘　　要：青藏高原是东亚海陆气相互作用最敏感的地区之一.青藏高原大气水分循环结构特征不仅反映了西风气流与'大三角扇形'影响域季风水汽流的相互作用特征,而且凸现出该区域为全球能量、水汽的交换关键区,构成'亚洲水塔'形成的重要背景;隆升的高原地形和强大的表面辐射加热形成了局地上升对流和高耸入对流层中部中空'热源柱'.研究揭示出此'热力驱动'下青藏高原高、低层互为反环流类似台风的自激反馈机制,其提供了'亚洲水塔'水汽'汇流'与抽吸动力效应.'亚洲水塔'热源驱动机制有助于'世界屋脊'大气'热岛'、'湿岛'的形成和维持,使暖湿气流从低纬海洋向高原输送、汇聚.针对'世界屋脊'高原对流频繁、云降水异常特征,揭示出'世界屋脊'空气低密度条件对高原对流云的触发效应.分析表明,低纬热带海洋成为'亚洲水塔'大气水分循环的重要水汽源区,水汽源区可跨越赤道追踪到南半球.提出了青藏高原'热力驱动'下大气水分循环结构类似全球性大气'水塔'的观点,青藏高原特殊的跨半球大气水分循环构建出'亚洲水塔'和其周边地区独特的大气-水文功能体系.给出了西风与季风协同作用背景下青藏高原为核心区的陆地-海洋-大气相互作用的'亚洲水塔'大气水分循环物理图像.From the perspective of regional and global atmospheric moisture circulation,this paper summarizes the unique thermal and dynamic mechanisms present in the Qinghai-Tibet Plateau(QTP)and their effects on the formation of the Asian Water Tower,which provides a theoretical basis for characterizing its atmospheric moisture circulation and global influence.The results show that the mechanisms of atmospheric moisture circulation in the QTP not only reflects the interaction between westerly and monsoon moisture flow but also highlight that the QTP is a key area for global and inter-hemispheric exchanges of energy and moisture.With a comprehensive dynamic analysis of the three-dimensional structure of the wind field based on apparent heat source calculations and the stream function,we revealed that the powerful ground radiation heating and the atmospheric heat source in the QTP lead to a hollow'heat island'and'wet island'in the middle troposphere.Driven by thermal forcing,a typhoon-like self-excited feedback dynamic structure with high and low circulation systems that occur in opposite directions occur over the plateau,which drive the convergence and pumping of atmospheric vapor over the Asian Water Tower.The vector field analysis of the water vapor flux also showed that the QTP can continuously capture water vapor from tropical areas at low latitudes,and its source area extends from the subtropical Indian subcontinent to the Bay of Bengal in the tropics,and it even crosses the equator into the southern hemisphere.In view of the frequent convection and abnormal cloud precipitation over the roof of the world,the large eddy simulation further revealed the unique trigger effect of the low air density on the convective clouds.We propose that the structure of atmospheric moisture circulation under the thermal drive of the QTP can be regarded as a global atmospheric water tower.According to a comprehensive analysis of the three-dimensional dynamic and thermodynamic structures,this atmospheric moisture circulation supplies the

关 键 词：青藏高原 亚洲水塔 大气水分循环 热力驱动机制 空气密度 物理图像 

分 类 号：P339[天文地球—水文科学] P426[水利工程—水文学及水资源]