青藏高原地-气间的物质/能量交换是高原与全球大气系统相联系的重要纽带。陡峭的地形和强烈的地表差异在高原山区形成特殊的局地大气环流系统,在地气交换中起着重要作用。为研究珠峰北坡的局地环流系统,于2006年5~6月间在珠峰北坡绒布河谷实施强化观测实验HEST2006,对该地区的局地环流以及辐射和热力状况进行观测,分析了该地区局地环流的日变化过程,包括:(1)地面风场的分布和变化;(2)风场垂直结构;(3)垂直运动及可能的驱动机制。研究表明,该地区局地大气环流是由地形与地表状态调整的大气辐射加热和冷却所驱动,包含多种不同的山地环流成分,与典型山谷风环流不同,具有很强的特殊性,对地气间的交换有重要影响。

The energy/matter exchange between the surface air and the troposphere is the important connection of the Tibetan Plateau and the global atmospheric systems.The great imhomogeneity in the topography and surface cover of the Tibetan mountain systems induces complicated local atmospheric circulations,and the circulations influence the exchange processes between the surface air and the troposphere over these regions.To better understand the local circulations in the Tibetan mountains,authors conducted the observational campaign HEST2006,in the Rongbuk Valley on the northern slope of Mt.Qomolangma,during May 29 and June 30,2006.In this study,the diurnal atmospheric circulation is analyzed,using the observed data,including the distribution and variation of surface wind,the vertical structure,the vertical motion,and the possible driving forces.It results in that the local circulation in this region is driven by the solar radiative heating and cooling with strong impacts of the topography and surface covers,and the local circulation is composed of various mountain circulation systems.