摘要
本文采用国际时间局（BIH）和美国喷气推进实验室（JPL）提供的日长变化序列（LOD）和美国气象中心（NMC）及日本气象厅（JMA）推导出的大气角动量（AAM）来重新检测固体地球和大气之间的季节性差异。从4种滤波序列中发现由AAM推出的LODt_atm周年变化高于观测的LOD约17％，而LOD的半年振癌变化超出LOD_atm的约30％。本文还讨论了几种因素，例如洋流中季节性变化，气象中的系统误差，平流层风的贡献，核的惯量矩作用，空气质量的重新分布补尝及其他本知的激发源来解释它们之间不平衡。今后10年，在研究角动量不平衡中，将用固体地球—大气—海洋动力学系统来代替简单的固体地球—大气的两体动力学系统。海洋对这季节性不平衡可能有重要贡献。
In this paper, the respective discrepancies of seasonal variation in earth-atmosphericbudget are reexamined using geodetic data provided by BIH and by JPL from a combinaion ofspace based observation of earth orientation as well as atmospheric angular momentum(AAM) data complited by U- S' National Meteorological Center(NMC) and by the JapaneseMeteorological Agency (JMA). From four filtered series, we find that the annual variationof the LOD derived from AAM is about 17% higher than the observed one. Semiannual vari ation of the observed LOD is about 30% excess contribution from AAM. The knowledge ofseasonal variation in ocean current, systematic errors in meteorological data,contribution ofstratospheric wind, role of moment of inertia of core, offset of redistribution of air mass andother unmodeled sources to explain the seasonal imbalances in the angular momentum budgetare discussed. Also in the coming decade, in the study of our planet's momentum balance, acoupled solid earth-atmosphere-ocean system, instead of the simpler two body solid earth-at mosphere system is suggest- The oceans may also contribute significantly to the seasonal an gular momentum badget.
出处
《中国科学院上海天文台年刊》
1996年第17期73-79,共7页
Annals Shanghai Astronomical Observatory Chinese Academy of Sciences
