极移和激发的研究  

Polar Motions and Their Excitation

作　　者：高布锡[1] 雷小平[1] 

机构地区：[1]中国科学院测量与地球物理所,武汉430077

出　　处：《天文学进展》2001年第2期317-321,共5页Progress In Astronomy

基　　金：国家自然科学基金项目(49904022)资助项目;中国科学院重点资助项目

摘　　要：极移可分为长期极移、钱德勒摆动（ＣＷ）、周年极移（ＡＮ）、不规则极移和短周期极移．由于极移运动对不同频率的激发响应是不同的，采用反卷积方法将极移序列进行了分离，对各类极移运动与激发的关系作了对比研究．认为周年极移与激发是逐年不同的，若能将它们逐年进行比较，将会对气象模型提供更好的约束条件．不规则极移可能反映了地球上较大规模的异常气象现象．Polar Motion is generally considered to include five main periodic or non-periodic wobbles,which are secular wobble, Chandler wobble, annual wobble, sub-seasonal wobble and irregular wobble, respectively. As the geophysical fluid excitations within different frequency scale can lead to the different responses of Polar Motion, here a Fourier desconvolution transform method is used to extract, in frequency domain, the five main wobbles from Polar Motion. Then these specific wobbles are compared with their corresponding geophysical fluid excitations one by one. Our results show that annual wobble and its excitation have time variable amplitudes and phases, so their year to year comparison would be a good constrain in angular momentum domain by testing the simulated atmospheric, oceanic and hydrological angular momentum functions deduced from general circulation models. In addition, irregular wobble may detect the abnormal signals forced by global unusual meteorological events.

关 键 词：激发 周年极移 不规则极移 钱德勒摆动 频率 反卷积方法 

分 类 号：P127.4[天文地球—天体测量]