摘要
利用最新的武汉地区高精度重力和全球高精度甚长基线干涉(very long baseline interferometry,VLBI)测量技术观测确定了地球液态地核的自由核章动本征参数(包括本征周期和品质因子等),同时获得了液核顶部的粘滞系数和液核的真实动力学椭率,使用Monte Carlo方法研究了本征周期的不确定度。结果表明,分别利用重力和VLBI确定的地球自由核章动本征周期值为430 sd(sd指恒星日)左右,两者间的差异为1.47 sd,粘滞系数为1 028 Pa·s。讨论了导致两者差异的主要原因,并将结果与国内外同类研究结果作了对比。
Based on the latest high-precision gravity data recorded in Wuhan and global high-accuracy VLBI(very long baseline interferometry) observations, we have determined the intrinsic parameters(including eigen-period and quality factor, et al) of FCN(free core nutation) of Earth's liquid core. Moreover, the viscosity at the top of the liquid core and its real dynamic ellipticity are obtained. By using the Monte Carlo method, we have calculated the uncertainty of the FCN's eigen-period. The results show that the FCN's eigen-periods determined by gravity and VLBI are about 430 sd and the difference between them is 1.47 sd, with the viscosity coefficient of 1 028 Pa·s. This paper discusses the main reasons for the above differences, and finally compares our results with similar research results from China and abroad.
引文
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