Mesospheric non-migrating tides generated with planetary waves: I. Characteristics
Mesospheric non-migrating tides generated with planetary waves: I. Characteristics
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DOI：
10.1016/j.jastp.2005.03.002
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发表时间：
2005-07
影响因子：
1.9
通讯作者：
H. G. Mayr;J. Mengel;E. Talaat;H. Porter;K. Chan
中科院分区：
文献类型：
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作者：
H. G. Mayr;J. Mengel;E. Talaat;H. Porter;K. Chan
根据 TIMED 航天器的测量结果和协调的地面观测，我们讨论了使用数值光谱模型 (NSM) 进行的建模研究的结果，该模型专门处理中间层中产生的非迁移潮汐。 NSM从地面延伸到热层，结合了小尺度重力波（GW）的海因斯多普勒扩展参数化，它描述了大气的主要动力学特征，包括波驱动的赤道振荡（QBO和SAO）以及潮汐和行星波（PW）的季节性变化。仅考虑太阳迁移潮汐的激发源，NSM 通过非线性相互作用也会产生中层中的非迁移潮汐，其幅度与观测到的潮汐相当。 （不包括由对流层潜热释放和对流等过程明确产生的重要非迁移潮。）大非迁移潮产生于纬向平均（波数m=0）的日和半日振荡以及m=1的半日振荡中。一般来说，所有纬向波数 m=1-4 都会产生显着的向东和向西传播的潮汐。为了查明原因，NSM 在没有太阳加热的情况下运行，以获得纬向平均值 (m=0)，并且由此产生的非迁移潮汐的振幅小到可以忽略不计。在这种情况下，由不稳定性产生的PW被人为地抑制。由此得出的结论是，正如之前提出的那样，非迁移潮是通过人工潮汐和迁移潮之间的非线性相互作用产生的。在随附的论文中，我们介绍了数值实验的结果，表明引力波滤波对产生所涉及的非线性耦合有显着贡献。
In light of the measurements from the TIMED spacecraft and coordinated ground-based observations, we discuss results from a modeling study with our Numerical Spectral Model (NSM), which specifically deals with the non-migrating tides generated in the mesosphere. The NSM extends from the ground to the thermosphere, incorporates Hines’ Doppler Spread Parameterization for small-scale gravity waves (GWs), and it describes the major dynamical features of the atmosphere including the wave driven equatorial oscillations (QBO and SAO), and the seasonal variations of tides and planetary waves (PWs). Accounting solely for the excitation sources of the solar migrating tides, the NSM generates through nonlinear interactions also non-migrating tides in the mesosphere that are comparable in magnitude to those observed. (The important non-migrating tides generated explicitly by processes like tropospheric latent heat release and convection are not included.) Large non-migrating tides are produced in the diurnal and semi-diurnal oscillations for the zonal mean (wave number m=0) and in the semidiurnal oscillation for m=1. In general, significant eastward and westward propagating tides are generated for all the zonal wave numbers m=1–4. To identify the cause, the NSM is run without the solar heating for the zonal mean (m=0), and the amplitudes of the resulting non-migrating tides are then negligibly small. In this case, the PWs generated by instabilities are artificially suppressed. This leads to the conclusion that the non-migrating tides are produced through nonlinear interactions between PWs and migrating tides, as had been previously proposed. In the accompanying paper, we present results from numerical experiments, which demonstrate that GW filtering contributes significantly to produce the nonlinear coupling that is involved.