青藏高原西部及东南周边地区季风前大气边界层结构分析  

Atmospheric Boundary Layer Structure in the West and the Southeastern Periphery of the Tibetan Plateau during the Pre-Monsoon Period

作　　者：朱春玲[1,2] 马耀明[1] 陈学龙[1,2] 

机构地区：[1]中国科学院青藏高原研究所,北京100085 [2]中国科学院研究生院,北京100049

出　　处：《冰川冻土》2011年第2期325-333,共9页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(4082501540810059006)资助

摘　　要：利用2008年JICA项目第一阶段(2008年2月25日至3月19日)的加密探空资料,分析了青藏高原西部及东南周边的大气边界结构特征.结果表明:青藏高原位温廓线均有明显的日变化,午后白天对流边界层达到最大,夜间稳定边界层在清晨达到最大.理塘和大理的稳定边界层绝大多数情况下在傍晚就开始发展,凌晨开始增强,清晨达到最大.对流边界层发展的同时低层大气出现超绝热层,其中改则的超绝热层能维持到19:00时稳定边界层形成,理塘和大理的近地超绝热层厚度较低且维持时间也较短.近地面层逆湿一般出现在夜间和凌晨,日出后逐渐消失.受大气热力作用的影响,边界层内水汽分布有着类似温度的分布特征.白天混合比有明显的混合层特征,日变化廓线保持不变或略微减小.在整个对流层里3个站均以西风为主导风向,低层大气有明显的东风气流,边界层内存在明显的风切变.The atmospheric boundary layer structure in the west and the southeastern periphery of the Tibet Plateau was analyzed by utilizing the intensifying sounding data encryption of the first phase of the JICA（Japan International Co-operation Agency） project.It is revealed that there is a visible diurnal variation of potential temperature profile over the plateau.The convective boundary layer reaches to the maximum in the afternoon and the stable boundary layer reaches to the maximum in the early morning.The stable boundary layers above Litang and Dali develop in the late afternoon,and then begin to enhance and reach to the maximum in the early morning.The super adiabatic layer appears with the convective boundary layer developing,while in Gêrzê the super adiabatic layer would exist till the stable boundary layer begin to develop.However,the super adiabatic layer is low thickness and has a relatively short time in Litang and Dali.Usually,the near surface moisture inversion occurs at night and early morning,and then gradually disappears after sunrise.With the effect of atmospheric heat,the profile of water vapor has a distribution similar to the potential temperature profile in the boundary layer.The mixing ratio has significant features of mixer layer in daytime,while diurnal variation profile of the ratio remains unchanged or slightly reduced.In the troposphere,where the three stations are dominated by westerly,atmospheric boundary layer has some significant east-wind flows and clear wind shear.

关 键 词：对流边界层 稳定边界层 逆温 超绝热 青藏高原 

分 类 号：P433[天文地球—大气科学及气象学]