Atmospheric excitation of the Earth's nutation: Comparison of different atmospheric models
Atmospheric excitation of the Earth's nutation: Comparison of different atmospheric models
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DOI：
10.1029/2000jb000042
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发表时间：
2002-02
影响因子：
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通讯作者：
M. Yseboodt;O. Viron;T. M. Chin;V. Dehant
中科院分区：
文献类型：
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作者：
M. Yseboodt;O. Viron;T. M. Chin;V. Dehant
[1]利用角动量方法，从五个大气环流模式中计算了大气对地球章动的影响。考虑了五种章动频率：一年一次、半年一次的章动频率、逆行章动频率和三年一次的章动频率。大气对18.6年章动的影响也从唯一的模式，给出了一个足够长的均匀序列进行了评估。从不同的模式和一个非倒置的气压计海洋模式得到的结果相互比较和比较观测和计算章动之间的残差。大气对地球章动的影响的评价被证明是以上的观测精度，特别是在每年的频率（反时针和逆行）和半年的反时针频率，但高度依赖于所使用的模型，加强了正确估计大气对章动的影响的重要性。用小波分析和滑动窗口最小二乘法研究了章动大气激发的时间演化。我们表明，激发振幅的波动高于观测的精度水平。
[1] Using the angular momentum approach, the effect of the atmosphere on the Earth's nutation is evaluated from five atmospheric circulation models. Five nutation frequencies are considered: the annual and semiannual prograde and retrograde and the terannual prograde. The atmospheric effect on the 18.6-year nutation is also evaluated from the only model that gives a long enough homogeneous series. The results obtained from the different models and a noninverted barometer ocean model are intercompared and compared with the residuals between the observed and computed nutations. The evaluation of the atmospheric effect on the Earth's nutation is shown to be above the observation precision, particularly at the annual frequency (prograde and retrograde) and the semiannual prograde frequency but is highly dependent on the model used, strengthening the importance of having a correct estimation for the atmospheric effects on nutation. The time evolution of the atmospheric excitation of the nutation is also studied, using a wavelet analysis and a sliding-window least squares method. We show that the fluctuations of the excited amplitude are above the level of precision of the observation.