热带气象学报2016，Vol.32Issue(5)：607-621,15.DOI:10.16032/j.issn.1004-4965.2016.05.004
论Rossby波在东、西风带中传播与频散I--谐波扰动Rossby波和指数扰动Rossby波
RESEARCH ON THE ROSSBY WAVE ON PROPAGATION AND DISPERSION IN THE WESTERLIES AND EASTERLIES,PART I:HARMONIC PERTURBATION ROSSBY WAVE & EXPONENTIAL PERTURBATION ROSSBY WAVE
摘要
Abstract
The classical Rossby wave is sought for solution from atmospheric perturbation equations for the qua-si-hydrostatic,quasi-geostrophic,horizontal quasi-nondivergent,and barotropic motions in the Cartesian coor-dinates.The solution of “meridional-zonal propagating harmonic wave”was obtained by solving a second-order ordinary differential equation,under the β-plane condition,from a second-order partial differential equation of a disturbance in meridional wind field.The classical Rossby wave owes its existence to the variation of the Coriolis parameter with latitude (the so-called “βeffect”)and holds its absolute vorticity conservation.In this paper, first a general solution of “meridional harmonic perturbation-zonal harmonic wave”(harmonic perturbation Rossby wave)is presented by solving the traditional Rossby wave equation of a second-order ordinary differential equation,which is equivalent to the traditional Rossby wave in that the harmonic perturbation Rossby wave formed in disturbance domain could continuously travel,as the meridional-zonal propagating harmonic wave, outside the domain.Likewise,the other general solution of “meridional exponential perturbation-zonal harmonic wave”(exponential perturbation Rossby wave)is introduced and compared with the harmonic perturbation Rossby wave with both phase speed and group velocity for their functional characteristics.So,we can redefine the Rossby wave just as zonal harmonic wave propagating and dispersing in the westerlies and easterlies with theβeffect and absolute vorticity conservation,which proceeds from an initial disturbance in the form of some har-monic,exponential and /or linear perturbation(s)that can be zero-order continuous or sectional-continuous each other in meridional wind field.Furthermore,just in terms of the formulae of phase speed and group velocity of the exponential perturbation Rossby wave,we give some preliminary analysis to interpret their motions of troughs and ridges as long,middle or short waves in the westerlies,including the blocking high’s formation and de-cline,long trough establishment and cold wave,generation of convective system and climate teleconnection, and to study the motions of easterly waves (inverted troughs),typhoon wave propagating and subtropical ridge moving westward /eastward in the easterlies.In general,all of the weather systems could exist as Rossby waves correlated with their perturbations of harmonic and /or exponential function form (s)in the meridional wind field.关键词
Rossby波/微扰方程/二阶常微分方程/谐波解/指数解/β效应/绝对涡度守恒Key words
Rossby wave/perturbation equation/second-order ordinary differential equation/harmonic pertur-bation/exponential perturbation/βeffect分类
天文与地球科学引用本文复制引用
辜旭赞,刘羽..论Rossby波在东、西风带中传播与频散I--谐波扰动Rossby波和指数扰动Rossby波[J].热带气象学报,2016,32(5):607-621,15.基金项目
国家自然科学基金项目“全球三次样条格式数值模式动力框架与理想场试验研究”（41275106）资助 （）
