Vertical and latitudinal structure of the migrating diurnal tide in the Martian atmosphere: Numerical investigations
Vertical and latitudinal structure of the migrating diurnal tide in the Martian atmosphere: Numerical investigations
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DOI：
10.1029/2005je002543
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发表时间：
2006
影响因子：
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通讯作者：
Y. Takahashi;H. Fujiwara;H. Fukunishi
中科院分区：
文献类型：
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作者：
Y. Takahashi;H. Fujiwara;H. Fukunishi
[1]利用大气环流模式和线性响应模式，研究了火星大气中低沙尘条件下(尘埃光学厚度为0.67μm，尘埃光学厚度为0.3时)日潮汐迁移的垂直和纬度结构。在我们的火星GCM中模拟的迁徙日潮汐很好地反映了以往观测和GCM研究中报道的迁徙日潮汐的一般特征。GCM模拟结果表明，春分时低纬地区日潮迁移的垂直波长为∼45公里，大于经典潮汐理论预测的主要传播模式(∼25-35公里)。Hough函数分解和利用LRM进行的数值实验表明，纬向平均涡度的影响是造成日潮迁移的大垂直波长的原因。结果表明，在纬向平均涡度不为零的情况下，通过行星自转效应的变化，使迁移的日潮汐的垂直波长增大。在地球的大气层中，没有观测到这种对迁徙的日潮的垂直波长的强烈依赖。火星半径大约是地球半径的一半，这将是导致火星大气比地球大气更有效的重要因素之一。
[1] We investigate the vertical and latitudinal structure of the migrating diurnal tide in a low dust condition (dust optical depth of 0.3 at 0.67 μm) in the Martian atmosphere by using a general circulation model (GCM) and a linear response model (LRM). The migrating diurnal tide simulated in our Mars GCM well represents general characteristics of the migrating diurnal tide which have been reported in previous observational and GCM studies. The GCM simulation shows that the vertical wavelength of the migrating diurnal tide in the low latitude region at equinox is ∼45 km which is larger than that of the major propagating mode predicted from the classical tidal theory (∼25–35 km). The Hough function decomposition and the numerical experiments using the LRM reveal that the large vertical wavelength of the migrating diurnal tide is caused by the effects of the zonal mean vorticity . It is suggested that the vertical wavelength of the migrating diurnal tide increases through the changes of the effects of the planetary rotation in the presence of non-zero zonal mean vorticity . Such a strong dependence of the vertical wavelength of the migrating diurnal tide on is not observed in the Earth's atmosphere. The Martian radius, about the half of the Earth's radius, would be one of the important factors to cause more effective in the Martian atmosphere than that in the Earth's atmosphere.