南亚夏季风对珠穆朗玛峰北坡地面风场的影响  

Impacts of the South Asian Summer Monsoon on Variations of Surface Wind on the Northern Slope of Mt. Qomolangma

作　　者：周立波[1] 邹捍[1] 马舒坡[1] 李鹏[1] 吴瑞欢 

机构地区：[1]中国科学院大气物理研究所低层大气探测部,北京100029 [2]杭州市萧山区气象局,浙江杭州311201

出　　处：《高原气象》2007年第6期1173-1186,共14页Plateau Meteorology

基　　金：中国科学院知识创新工程重要方向项目(KZCX3-SW-231);国家自然科学基金委重点项目(40533018);中国科学院大气物理研究所前沿领域创新项目(8-070203)共同资助

摘　　要：喜马拉雅山区毗邻南亚季风区，其陡峭的地形和复杂的地表状态在强烈太阳辐射条件下形成了特殊的局地环流系统。为了正确理解该环流系统与南亚天气气候过程的可能关联，本文利用HEST2006珠穆朗玛峰绒布河谷强化实验期间获得的2006年5～6月的地面观测资料和实时的大气环流资料，对该地区地面风场与南亚夏季风的关系进行了研究。研究表明，南亚夏季风间歇期，喜马拉雅山区以晴空天气为主，太阳辐射强烈，绒布河谷地区地面盛行沿河谷方向的偏南下行气流；南亚夏季风强盛期，喜马拉雅山区多为云雨天气，太阳辐射减弱，地面风场强度明显减弱。结果表明，喜马拉雅山地区山谷内部的地面环流系统几乎不受其高层大气环流的影响，而与太阳辐射通量及南亚夏季风指数关系密切。因此，我们认为南亚夏季风对喜马拉雅山区地面环流的影响，主要是通过改变该地区的大气热力和辐射状况完成的。The Himalayas is near the South Asian monsoon region, with a special local circulation system induced by its steep topography and complex terrains. For better understanding the circulation system and its possible relationship with the weather pattern over the South Asian regions, we analyzed the variation of surface wind in the Rongbuk valley on the northern slope of Mt. Qomolangma and its responses to the South Asian summer monsoon （SASH）, using the observation data obtained during NEST2006 cam- paign in June 2006 and real-time atmospheric circulation data. During the weak SASH period, the Himalayan regions are mainly dominated by clear days, and the northward surface wind prevails in the Rongbuk valley with a strong solar radiation;while during the strong SASH period, the surface wind and the solar radiation in the Rongbuk valley becomes weak, and the Himalayan regions are mainly controlled by the cloudy and rainy weather conditions. The analyszd result showed that the local circulation in the Rongbuk valley has little responses to the atmospheric circulation at the upper levels, but is closely related to the solar radiation flux and SASH index. Therefore, we concluded that the SASH could have impacts on the Himalayan surface circulation by changing the local thermal and radiation conditions.

关 键 词：喜马拉雅山 珠穆朗玛峰 南亚夏季风 局地环流 

分 类 号：P452.42[天文地球—大气科学及气象学]