夏季副热带高压北移的非线性机理探讨  

PRIMARY STUDY OF THE NONLINEAR MECHANISM ABOUT SUMMER SUBTROPICAL HIGH MOVING NORTHWARD

作　　者：郑祖光[1] 李秀玲[1] 刘莉红[1] 吴洪[1] 

机构地区：[1]中国气象局培训中心,北京100081

出　　处：《气象学报》2005年第3期278-288,共11页Acta Meteorologica Sinica

基　　金：国家自然科学基金项目(49875018)

摘　　要：文中建立了含22个变量的强迫、耗散、非线性的斜压大气动力系统。该系统包含了超长波、长波和纬向气流三者的相互作用;反映了北半球两大洋、两大陆的“二波型”的纬向和经向非均匀热力强迫;采用相轨线图、流函数图以及Poincar啨图相结合的方法,归纳出若干典型的流动体制和环流型式;用长方形通道中的流动近似地表征北半球环流。结果表明:(1)该系统能很好地刻画斜压大气中7种流动体制及其转换;随着夏季热力强迫的增大,系统状态经历了R1R12V-NVR12的变化。(2)刻画了4种主要的环流型式及其转换;随着夏季热力强迫的增大,环流型从G2转G3,即副高季节性北移西伸。(3)系统的流动体制和环流型式之间的联系表现为:夏季副热带高压北移西伸即G2转G3的变化,对应着流动体制由Rossby流转振荡态(R12V-NV);副热带高压在偏北位置上的南北向和东西向的振荡活动,则对应着系统振荡态的维持。One of the most characteristic atmospheric circulation processes is that summer subtropical high over Pacific moves northward and extends westward, which affects China’s weather and climate significantly. Subtropical high over Pacific moves northward by the effect of meridian heating field changing from June to August each year. It is the seasonal catastrophe of the Northern Hemisphere to global atmospheric circulation, especially by jumping northward. Mechanism of summer subtropical high moving northward was discussed by applying dynamical system theory and method. Baroclinic atmospheric system containing ultra-long wave, long wave and zonal current interacted was built firstly, then phase trajectory figure, stream function figure, Poincaré section map and phase variable time graph were used to analyze the evolving of system states and circulation patterns, especially to examine subtropical high and its moving northward seasonally, by the effect of summer zonal inhomogeneous inposed thermal field together with friction dissipation. The nonlinear system theory and method were used to discuss subtropical high variation mechanism and new research were explored:(1)the higher steps dynamical system(22 variance) considering ultra-long wave,long wave and zonal flow which interacted was built.(2)it was designed to a summer inhomogeneous thermal field of two-ocean and two-continent in the Northern Hemisphere.(3)The system states were analyzed synthetically by phase trajectory figure,Poincaré section map and phase variable time graph, and the states distribution of parameter plane (θ*K,k) was drawn, and stream function isoclines graph of rectangle passage(to be shown as the Northern Hemisphere approximately) was also drawn by renewed stream function.Several characteristic circulation patterns were sum up,and the distribution of circulation patterns were acquired with the plane(θ*K,k).Subtropical high moving northward was discussed by combining system states and circulation patterns.The main results were

关 键 词：副热带高压 非线性 夏季 机理探讨 北移 热力强迫 斜压大气 动力系统 相互作用 纬向气流 相轨线图 方形通道 系统状态 系统振荡 北半球 R12 流动 体制 超长波 非均匀 函数图 型式 季节性 环流型 东西向 南北向 刻画 增大 

分 类 号：P458.121.1[天文地球—大气科学及气象学] TQ442[化学工程—化学肥料工业]