局地大气能量有效性中的表面扰动位能特征  

Characteristics of the surface perturbation potential energy in the local atmospheric energetic efficiency

作　　者：高丽[1] 李建平[2] 

机构地区：[1]中国气象局国家气象中心,北京100081 [2]中国科学院大气物理研究所LASG,北京100029

出　　处：《气象学报》2011年第4期664-671,共8页Acta Meteorologica Sinica

基　　金：国家自然科学基金项目(40705021);国家重点基础研究发展计划项目(2010CB950402)

摘　　要：在局地扰动位能理论工作基础上,进一步研究了与实际地形有关的表面扰动位能部分,理论推导了数学表达式,表明地形和表面热状况是其决定因素。利用再分析资料考察了其气候学和气候变率特征。研究表明,表面扰动位能具有独特的热动力学意义,它的量值与地球表面高大地形密切联系,而其季节变动特点则与表面热状况的季节变化息息相关。高纬度极地地形区域为明显的全年基本不变的负扰动位能分布区,低纬度热带区域则呈现季节变动非常小的正扰动位能分布。表面扰动位能的季节变动和年际变率的极值区都位于北半球中纬度的高大地形区域,夏季达到正的极大值,而冬季则转变成负值区。这一特征在青藏高原区最为典型,其表面扰动位能在时域和频域上均表现出明显的年代际特征,年际变率以2—4a周期为主。Based on the previous theoretical analyses of the local perturbation potential energy,the surface perturbation potential energy（SPPE） component associated with topography and its features are further been investigated by using the NCEP reanalysis dataset in this study.The results show that the SPPE has particular thermal and dynamical properties,and close relationships with the large topography in lands.Furthermore,the seasonal variation of the SPPE is closely dependent upon the seasonal variation of land surface properties.Analyses show that the negative perturbation potential energy primarily distributes over the polar region and the positive one is over the tropical region,where the SPPE almost keeps constant throughout the year or slightly changes only at the seasonal scale.The extrema of the SPPE at both the seasonal and annual scales are located over mid-latitude areas in the north hemisphere where lots of large topography lie.These extrema show positive in boreal summertime and negative in boreal wintertime.Such characteristics is the most typical over the Qinghai-Tibet Plateau,where the SPPE is featured by evident interdecadal variability in time and frequency domains,and interannual variability with a leading period of 2-4 years.

关 键 词：表面扰动位能 大气能量 热源 地形 

分 类 号：P433[天文地球—大气科学及气象学]