[A-CG40] 海洋と大気の波動・渦・循環の力学

[ACG40-P02] 金星GCMで再現されるスーパーローテーションの⽔平超粘性への依存性

*杉本 憲彦¹、藤澤 由貴子²、小守 信正²、樫村 博基³、高木 征弘⁴、松田 佳久⁵ (1.慶應義塾大学　法学部　日吉物理学教室、2.慶應義塾大学　自然科学研究教育センター、3.神戸大学　理学研究科、4.京都産業大学　理学部、5.東京学芸大学　宇宙地球科学分野)

キーワード：金星大気、スーパーローテーション、大気大循環モデル、水平粘性

Horizontal diffusion and resolution are important factors to generate and maintain the super-rotation in the general circulation model (GCM) because waves which transport angular momentum are sensitive to them. Here, we investigated how the super-rotation depends on the magnitude of horizontal hyper diffusion using a Venus atmospheric GCM with medium and high resolutions. In both the runs, we found a parameter range where the structure of fully developed super-rotation is almost independent of the magnitude of horizontal diffusion. Spectral analysis shows that unrealistically strong super-rotation is developed when medium-scale disturbances are dissipated by stronger horizontal diffusion. On the other hand, artificially weak super-rotation is also realized because spurious small-scale disturbances are accumulated when the horizontal diffusion is too weak.