A GCM Study on the 4-Day and 5-Day Waves in the Venus Atmosphere
A GCM Study on the 4-Day and 5-Day Waves in the Venus Atmosphere
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金星大气中4日和5日波的GCM研究
DOI：
10.1029/2021je007164
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
and Yoshihisa Matsuda
中科院分区：
文献类型：
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作者：
Masahiro Takagi;Hiroki Ando;Norihiko Sugimoto;and Yoshihisa Matsuda
在金星大气云顶观测到的4天和5天波预计将在维持大气环流方面发挥重要作用。然而，它们还没有被复制在金星大气环流模式（GCM）到目前为止，其结构和激发机制仍然知之甚少。使用改进的金星GCM，我们成功地再现了行星尺度的3.3天和5.8天波，它们被认为分别对应于4天和5天波。我们还得到了4.8天波，其结构与5.8天波相似。这些波的三维结构由低纬度的开尔文波和中高纬度的一个或两个Rossby波组成，它们在临界纬度处相连。这一事实表明，它们是由Rossby-Kelvin不稳定性激发的。在云顶可以观测到3.3天波的开尔文模式，而5.8天和4.8天波由于临界水平而无法观测到。5.8天波的中纬度Rossby模态主要由在云顶关于赤道对称的中纬度涡旋主导;这一结果与观测结果非常一致。由这些波引起的向赤道方向的角动量通量可能对金星的超旋转有贡献。5.8天和4.8天波的Rossby模态在云层中具有斜压结构，导致显著的向极热通量。在金星大气中观察到的关于赤道对称的行星尺度结构可以用这些波来解释。
The 4‐day and 5‐day waves observed at the cloud top in the Venus atmosphere are expected to play important roles in the maintenance of the general circulation. However, they have not been reproduced in Venus general circulation models (GCMs) so far, and their structures and excitation mechanisms remain poorly understood. Using an improved Venus GCM, we succeeded in reproducing the planetary‐scale 3.3‐day and 5.8‐day waves, which are considered to correspond to the 4‐day and 5‐day waves, respectively. We also obtained the 4.8‐day wave, whose structure is similar to that of the 5.8‐day wave. The three‐dimensional structures of these waves consist of a Kelvin wave in low latitudes and one or two Rossby waves in mid‐ and high latitudes that are connected at the critical latitudes. This fact indicates that they are excited by the Rossby‐Kelvin instability. The Kelvin mode of the 3.3‐day wave could be observed at the cloud top, while those of the 5.8‐day and 4.8‐day waves cannot be observed due to the critical levels. The mid‐latitude Rossby mode of the 5.8‐day wave is dominated by mid‐latitude vortices symmetric about the equator at the cloud top; this result is quite consistent with the observations. The equatorward angular momentum flux induced by these waves could contribute to the Venus superrotation. The Rossby modes of the 5.8‐day and 4.8‐day waves have baroclinic structures in the cloud layer inducing significant poleward heat flux. The planetary‐scale structures symmetric about the equator observed in the Venus atmosphere could be explained by these waves.