基于时变地球主惯性矩的三轴地球的自由Euler运动  

Free Euler Motion of the Triaxial Earth Based on Temporary Principal Moments of Inertia of the Earth

作　　者：申文斌[1,2] 陈巍[1] 李进[1] 

机构地区：[1]武汉大学测绘学院,武汉市430079 [2]武汉大学地球空间环境与大地测量教育部重点实验室,武汉市430079

出　　处：《武汉大学学报（信息科学版）》2008年第8期859-863,共5页Geomatics and Information Science of Wuhan University

基　　金：国家自然科学基金资助项目(40574004,40637034);中国科学院动力大地测量学重点实验室开放研究基金资助项目(L06-02)

摘　　要：在时变地球主惯性矩情形,采用数值方法求解了自由Euler动力学方程和运动学方程。结果表明,地球存在周期约为304.5 d的自由章动;旋转速度的三个分量均出现周期性的增大和减小;地球主惯性矩A、B、C的时变性导致Euler周期产生复杂的波动,特别是ω3(自转速率)存在周期为22 a1、4 a、8 a4、a、2 a、周年以及更短周期的波动,这表明A、B、C的时变性导致了10 a尺度、周年以及更短周期的日长变化。Reinvestigation of the Earth rotation is of scientific significance since the principle moments of inertia of the Earth, A, B, C are not equivalent with each other, and they are time-dependent. Numerical calculations of Euler＇s dynamic equations are provided when the temporal nature of the moments of inertia is taken into account. The results show that there is a free wobble with a period of 304. 5 days; the three components of the angular velocity increase and decrease periodically; the variations of A, B, C lead to complex fluctuations of the Euler period, and especially, ω3 has oscillation periods 22, 14, 8, 4, 2 and 1 years as well as even shorter periods. In another word, the decadal, annual and even shorter-period fluctuations of length of day are closely related with the variations of A, B, C.

关 键 词：时变主惯性矩 三轴地球自由Euler运动 椭圆积分数值解 

分 类 号：P223.0[天文地球—大地测量学与测量工程]