【摘要】 用高精度的现代日长观测结果、近 2 0年的J2 变化的结果和古地球自转结果 ,讨论了日长和J2 变化的长期和长周期的主要特性 ,从理论和实测两方面分析了日长和J2 变化的关系及其异同 ,认为J2 变化的结果在地球动力学研究中的作用应予以重视 ,综合利用日长和J2 将使这两种资料的潜力得以进一步发挥。更多还原

【Abstract】 The characters of the secular and long_period variations in the length of day and the harmonic coefficient J 2 of geopotential were analyzed based on the recent observational result of the length of day,the result of J 2 variations in the recent twenty years and the ancient astronomical result of the Earth rotation.Then the relation and difference between variations of the length of day and J 2 were discussed according to the theory of the Earth rotation and gravity.Furthermore we stressed the importance of J 2 and the integrated use of the length of day and J 2 for geodynamics.更多还原