摘要
采用 1 979- 1 995年期间新的大气角动量资料 ,研究了大气在季节性时间尺度上对日长变化和极移的贡献 .结果表明 ,考虑了风和大气压的贡献后 ,大气在周年和半年时间尺度上对日长变化的贡献分别可达 95%和 88% .同时还给出了大气对极移激发的定量结果 .其中 ,大气在周年尺度上对极移X分量的贡献为 1 6% ,对Y分量的贡献为 43% ;在半年尺度上对极移X分量的贡献为 9% ,对Y分量的贡献为 30 % .根据以上的研究结果 ,表明还需考虑海洋的贡献 ,才能进一步解决地球自转激发的问题 .
The contribution of AAM to earth rotation changes on seasonal time scale is studied in this paper. The new reanalysis of AAM data during 1979-1995 provided by NCEP/NCAR is used. The results show that the contributions of the atmosphere to the annual and semi annual LOD changes are 95% and 88%, respectively, including the contributions of atmospheric wind and pressure. The results of the excitation to polar motion are also presented. On annual time scale, the contributions to X and Y components of polar motion are 16% and 43%, respectively, while on semi annual time scale, the contributions are 9% and 30%. It is pointed out that the oceans and wind above 10mbar should be considered in the research of earth rotation changes.
出处
《天文学报》
CSCD
北大核心
2000年第2期148-152,共5页
Acta Astronomica Sinica
关键词
大气角动量
地球自转变化
季节性时间尺度
大气
atmospheric angular momentum, earth rotation change, seasonal time scale
