日本地球惑星科学連合2018年大会

講演情報

[EE] Eveningポスター発表

セッション記号 P (宇宙惑星科学) » P-PS 惑星科学

[P-PS04] あかつきの成果と、金星科学の深化

2018年5月22日(火) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:佐藤 毅彦(宇宙航空研究開発機構・宇宙科学研究本部)、堀之内 武(北海道大学地球環境科学研究院)、山本 勝(九州大学応用力学研究所、共同)、Kevin McGouldrick(University of Colorado Boulder)

[PPS04-P03] 金星雲層を想定した鉛直対流の 3 次元数値計算

*杉山 耕一朗1小高 正嗣2中島 健介3石渡 正樹2今村 剛4林 祥介5 (1.松江工業高等専門学校情報工学科、2.北海道大学大学院宇宙理学専攻、3.九州大学大学院理学研究院地球惑星科学部門、4.東京大学大学院新領域創成科学研究科、5.神戸大学大学院理学研究科惑星学専攻/惑星 科学研究センター(CPS))

キーワード:惑星大気、数値モデリング

Although convection has been suggested to occur in the lower part of Venus' cloud layer by some observational evidences, its structure remains to be clarified. In the previous studies, Baker et al (1998, 2000) and Imamura et al (2014) try to simulate Venus' cloud-level convection, but the model they utilized is two-dimensional. Lefevre et al (2017) also perform a three-dimensional simulation using only similar settings of Imamura et al (2014). However, a three-dimensional numerical calculation using similar settings of Baker et al has not been performed yet. Here we report on the results of our numerical simulations performed in order to investigate a possible three-dimensional structure of Venus' cloud-level convection using similar settings of both Baker's and Imamura's.

We use the convection resolving model developed by Sugiyama et al. (2009). The model is based on the quasi-compressible system (Klemp and Wilhelmson, 1978), and is used in the simulations of the atmospheric convections of Jupiter (Sugiyama et al., 2011, 2014) and Mars (Yamashita et al. 2017). We perform two experiments. The first one, which we call Ext.B, is based on Baker et al. (1998). A constant turbulent mixing coefficient is used in the whole computational domain, and a constant heat flux is given at the upper and lower boundaries as a substitute for radiative forcing. The second one, which we call Exp.I, is based on Imamura et al. (2014). The sub-grid turbulence process is implemented by Klemp and Wilhelmson (1989), and an infrared heating profile obtained in a radiative-convective equilibrium calculation (Ikeda, 2011) is used. In both of the experiments, the temporally averaged solar heating profile is used. The spatial resolution is 200 m in the horizontal direction and 125 m in the vertical direction. The domain covers 128 km x 128 km horizontally and altitudes from 40 km to 60 km. The horizontal domain size is set to be larger than that employed in Lefevre et al (2017) in order to permit the excitation of larger scale gravity waves.

In our poster, we will discuss the difference of convective motions and heat budgets obtained in Exp.B and Exp.I. We will also show the propagation of gravity wave driven by convection.