Forcing mechanisms of the terdiurnal tide
Forcing mechanisms of the terdiurnal tide
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DOI：
10.5194/acp-18-15725-2018
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发表时间：
2018-11
影响因子：
6.3
通讯作者：
F. Lilienthal;C. Jacobi;Christoph Geißler
中科院分区：
文献类型：
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作者：
F. Lilienthal;C. Jacobi;Christoph Geißler
抽象的。本文利用一个非线性的全球环流模式，分析了中层大气中迁移的周日潮的可能的强迫机制，即，太阳辐射在水汽和臭氧带的吸收，非线性潮汐相互作用，重力波潮汐相互作用。与全日潮和半日潮的强迫机制相比，人们对这些全日潮强迫机制的了解较少，并且对它们各自的相关性存在相互矛盾的观点。在我们的模拟中，我们删除了波数3模式，每个单独的强迫和分析剩余的潮汐风和温度场。我们发现，太阳直接强迫是占主导地位的，并解释了大部分的迁移terdiarydearned潮的振幅。由于其他潮汐或重力波的非线性相互作用是最重要的，在当地的冬季。进一步的分析表明，非线性强迫由于相消干涉而局部抵消了太阳强迫。因此，潮汐振幅可以变得更大的模拟与删除非线性强迫。
Abstract. Using a nonlinear mechanistic global circulation model we analyze the migrating terdiurnal tide in the middle atmosphere with respect to its possible forcing mechanisms, i.e., the absorption of solar radiation in the water vapor and ozone band, nonlinear tidal interactions, and gravity wave–tide interactions. In comparison to the forcing mechanisms of diurnal and semidiurnal tides, these terdiurnal forcings are less well understood and there are contradictory opinions about their respective relevance. In our simulations we remove the wave number 3 pattern for each forcing individually and analyze the remaining tidal wind and temperature fields. We find that the direct solar forcing is dominant and explains most of the migrating terdiurnal tide's amplitude. Nonlinear interactions due to other tides or gravity waves are most important during local winter. Further analyses show that the nonlinear forcings are locally counteracting the solar forcing due to destructive interferences. Therefore, tidal amplitudes can become even larger for simulations with removed nonlinear forcings.