| Atmospheric Excitation of Time Variable Length-of-Day on Seasonal Scales |
| |
| 作者姓名： | Li-Hua Ma Yan-Ben Han National Astronomical Observatories Chinese Academy of Sciences Beijing |
| |
| 作者单位： | Li-Hua Ma Yan-Ben Han National Astronomical Observatories，Chinese Academy of Sciences，Beijing 100012 |
| |
| 基金项目： | Supported by the National Natural Science Foundation of China |
| |
| 摘 要： | We use the method of wavelet transform to analyze the time series of the Earth's rotation rate of the EOP(IERS)C04.The result shows that the seasonal (annual and semiannual)variation of the length-of-day(LOD)has temporal vari- ability in its period length and amplitude.During 1965.0-2001.0,the periods of the semiannual and annual components varied mainly from 175-day to 190-day and from 360-day to 370-day,respectively;while their amplitudes varied by more than 0.2 ms and 0.1 ms,respectively.Analyzing the axial component of atmospheric angular mo- mentum(AAM)during this period,we have found that time-variations of period lengths and amplitudes also exist in the seasonal oscillations of the axial AAM and are in good consistency with those of the seasonal LOD change.The time variation of the axial AAM can explain largely the change of the LOD on seasonal scales.
|
| 关 键 词： | 地球旋转 季节变化 波转换 地球轨道平面 |
Atmospheric Excitation of Time Variable Length-of-Day on Seasonal Scales |
| |
| Li-Hua Ma Yan-Ben Han National Astronomical Observatories,Chinese Academy of Sciences,Beijing .Atmospheric Excitation of Time Variable Length-of-Day on Seasonal Scales[J].Chinese Journal of Astronomy and Astrophysics,2006,6(1):120-124. |
| |
| Authors: | Li-Hua Ma Yan-Ben Han |
| |
| Institution: | National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 |
| |
| Abstract: | We use the method of wavelet transform to analyze the time series of the Earth's rotation rate of the EOP(IERS)C04.The result shows that the seasonal (annual and semiannual)variation of the length-of-day(LOD)has temporal vari- ability in its period length and amplitude.During 1965.0-2001.0,the periods of the semiannual and annual components varied mainly from 175-day to 190-day and from 360-day to 370-day,respectively;while their amplitudes varied by more than 0.2 ms and 0.1 ms,respectively.Analyzing the axial component of atmospheric angular mo- mentum(AAM)during this period,we have found that time-variations of period lengths and amplitudes also exist in the seasonal oscillations of the axial AAM and are in good consistency with those of the seasonal LOD change.The time variation of the axial AAM can explain largely the change of the LOD on seasonal scales. |
| |
| Keywords: | Earth rotation-seasonal variation-wavelet transform |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ |
