あかつき・地上観測と数値モデリングの連携による金星大気力学の研究

2019 Fiscal Year Annual Research Report

• Project/Area Number: 16H02225
• Research Institution: Tokyo Gakugei University
• Principal Investigator: 松田 佳久 東京学芸大学, 教育学部, 研究員 (60134772)
• Co-Investigator(Kenkyū-buntansha): 高木 征弘 京都産業大学, 理学部, 教授 (00323494) ; 関口 美保 東京海洋大学, 学術研究院, 准教授 (00377079) ; 安藤 紘基 京都産業大学, 理学部, 助教 (00706335) ; 杉本 憲彦 慶應義塾大学, 法学部(日吉), 准教授 (10402538) ; 佐川 英夫 京都産業大学, 理学部, 准教授 (40526034) ; 神山 徹 国立研究開発法人産業技術総合研究所, 情報・人間工学領域, 主任研究員 (40645876) ; 樫村 博基 神戸大学, 理学研究科, 講師 (80635186) ; 大月 祥子 専修大学, 商学部, 准教授 (90523291)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 金星大気 / 惑星気象学

Outline of Annual Research Achievements

Venus Expressとあかつきの電波掩蔽観測データを解析し，高度40-85 kmにおける気温分布と大気安定度分布を全球的に取得した。緯度70度より低緯度側では，安定度分布が過去の直接観測と整合的であることがわかった。緯度70度より極域側では、雲層の下 (高度42 kmあたり) まで安定度の低い領域が続いていることが分かった。このような安定度の低い領域が極域の深くまで存在することは，そこで活発な大気の鉛直運動が生じていることを示唆し，極域の分厚い雲の生成・維持に寄与している可能性がある。
あかつき中間赤外カメラによる観測 (Kouyama et al., 2019) との比較の結果，GCMで再現された熱潮汐波 (Takagi et al., 2018) の位相分布が，雲層上端高度の低緯度域で半波長ほど東西方向にずれていることが明らかになった。その原因を調べたところ，雲頂低緯度の熱潮汐波の位相は主に半日潮によって決定され，その位相分布は高度60-70 km付近の大気安定度に強く影響されることがわかった。最近の電波掩蔽観測の結果を参照し，より現実的な安定度分布を用いると，観測と整合的な位相分布が得られることも示された。
2018年8月と2019年1月・2月にNASAの赤外望遠鏡 IRTF を利用し，金星の昼面および夜面を分光観測した。昼面 (雲層付近を観測) の観測スペクトルには，CO2 の吸収線に加えて，HDO および HCl の吸収線が観測された。HCl に関しては，過去のVenus Express探査機による観測 (Mahieux et al., 2015) と他の地上観測 (Krasnopolsky, 2010) とで導出された存在量におよそ10倍もの不一致が存在している。今回の IRTF での観測により，この不一致問題に新たな制約を加えることができると期待される。

Research Progress Status

令和元年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和元年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] Laboratoire de Meteorologie Dynamique(フランス)
  • Country Name: FRANCE
  • Counterpart Institution: Laboratoire de Meteorologie Dynamique
• [Int'l Joint Research] Observatorio Astronomico de Lisboa(ポルトガル)
  • Country Name: PORTUGAL
  • Counterpart Institution: Observatorio Astronomico de Lisboa
• [Int'l Joint Research] NASA(米国)
  • Country Name: U.S.A.
  • Counterpart Institution: NASA
• [Journal Article] Venus' cloud top wind study: Coordinated Akatsuki/UVI with cloud tracking and TNG/HARPS-N with Doppler velocimetry observations (2020)
  • Author(s): Gonsalves Ruben、Machado Pedro、Widemann Thomas、Peralta Javier、Watanabe Shigeto、Yamazaki Atsushi、Satoh Takehiko、Takagi Masahiro、Ogohara Kazunori、Lee Yeon-Joo、Harutyunyan Avet、Silva Jose
  • Journal Title: Icarus Volume: 335 Pages: 113418～113418
  • DOI: 10.1016/j.icarus.2019.113418
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Thermal structure of the Venusian atmosphere from the sub-cloud region to the mesosphere as observed by radio occultation (2020)
  • Author(s): Ando Hiroki、Imamura Takeshi、Tellmann Silvia、Patzold Martin、Hausler Bernd、Sugimoto Norihiko、Takagi Masahiro、Sagawa Hideo、Limaye Sanjay、Matsuda Yoshihisa、Choudhary Raj Kumar、Antonita Maria
  • Journal Title: Scientific Reports Volume: 10 Pages: 1-7
  • DOI: 10.1038/s41598-020-59278-8
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Dayside cloud top structure of Venus retrieved from Akatsuki IR2 observations (2020)
  • Author(s): Sato T.M.、Satoh T.、Sagawa H.、Manago N.、Lee Y.J.、Murakami S.、Ogohara K.、Hashimoto G.L.、Kasaba Y.、Yamazaki A.、Yamada M.、Watanabe S.、Imamura T.、Nakamura M.
  • Journal Title: Icarus Volume: 345 Pages: 113682～113682
  • DOI: 10.1016/j.icarus.2020.113682
  • Peer Reviewed
• [Journal Article] Fully Developed Superrotation Driven by the Mean Meridional Circulation in a Venus GCM (2019)
  • Author(s): Sugimoto Norihiko、Takagi Masahiro、Matsuda Yoshihisa
  • Journal Title: Geophysical Research Letters Volume: 46 Pages: 1776～1784
  • DOI: 10.1029/2018GL080917
  • Peer Reviewed
• [Journal Article] Planetary‐Scale Variations in Winds and UV Brightness at the Venusian Cloud Top: Periodicity and Temporal Evolution (2019)
  • Author(s): Imai Masataka、Kouyama Toru、Takahashi Yukihiro、Yamazaki Atsushi、Watanabe Shigeto、Yamada Manabu、Imamura Takeshi、Satoh Takehiko、Nakamura Masato、Murakami Shin‐ya、Ogohara Kazunori、Horinouchi Takeshi
  • Journal Title: Journal of Geophysical Research: Planets Volume: 124 Pages: 2635～2659
  • DOI: 10.1029/2019JE006065
  • Peer Reviewed
• [Journal Article] Observing system simulation experiment for radio occultation measurements of the Venus atmosphere among small satellites (2019)
  • Author(s): SUGIMOTO Norihiko、ABE Mirai、KIKUCHI Yukako、HOSONO Asako、ANDO Hiroki、TAKAGI Masahiro、GARATE LOPEZ Itziar、LEBONNOIS Sebastien、AO Chi
  • Journal Title: Journal of Japan Society of Civil Engineers, Ser. A2 (Applied Mechanics (AM)) Volume: 75 Pages: I_477～I_486
  • DOI: 10.2208/jscejam.75.2_I_477
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Stationary Features at the Cloud Top of Venus Observed by Ultraviolet Imager Onboard Akatsuki (2019)
  • Author(s): Kitahara Takehiko、Imamura Takeshi、Sato Takao M.、Yamazaki Atsushi、Lee Yeon Joo、Yamada Manabu、Watanabe Shigeto、Taguchi Makoto、Fukuhara Tetsuya、Kouyama Toru、Murakami Shin‐ya、Hashimoto George L.、Ogohara Kazunori、Kashimura Hiroki、Horinouchi Takeshi、Takagi Masahiro
  • Journal Title: Journal of Geophysical Research: Planets Volume: 124 Pages: 1266-1281
  • DOI: 10.1029/2018JE005842
  • Peer Reviewed
• [Journal Article] Impact of Data Assimilation on Thermal Tides in the Case of Venus Express Wind Observation (2019)
  • Author(s): Sugimoto Norihiko、Kouyama Toru、Takagi Masahiro
  • Journal Title: Geophysical Research Letters Volume: 46 Pages: 4573～4580
  • DOI: 10.1029/2019GL082700
  • Peer Reviewed
• [Journal Article] Global Structure of Thermal Tides in the Upper Cloud Layer of Venus Revealed by LIR on Board Akatsuki (2019)
  • Author(s): Kouyama T.、Taguchi M.、Fukuhara T.、Imamura T.、Horinouchi T.、Sato T. M.、Murakami S.、Hashimoto G. L.、Lee Y. J.、Futaguchi M.、Yamada T.、Akiba M.、Satoh T.、Nakamura M.
  • Journal Title: Geophysical Research Letters Volume: 46 Pages: 9457～9465
  • DOI: 10.1029/2019GL083820
  • Peer Reviewed
• [Journal Article] Long-term Variations of Venus’s 365 nm Albedo Observed by Venus Express, Akatsuki, MESSENGER, and the Hubble Space Telescope (2019)
  • Author(s): Lee Y.J., K.-L. Jessup, S. Perez-Hoyos, D.V. Titov, S. Lebonnois, J. Peralta, T. Horinouchi, T. Imamura, S. Limaye, E. Marcq, M. Takagi, A. Yamazaki, M. Yamada, S. Watanabe, S. Murakami, K. Ogohara, W.M. McClintock, G. Holsclaw, and A. Roman
  • Journal Title: The Astronomical Journal Volume: 158 Pages: 126～126
  • DOI: 10.3847/1538-3881/ab3120
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Mean meridional circulation in the Venus atmosphere (2020)
  • Author(s): Takagi, M., N. Sugimoto, H. Ando, H. Kashimura, and Y. Matsuda
  • Organizer: Symposium on Planetary Sciences 2020
  • Int'l Joint Research
• [Presentation] Data assimilation of the Venus atmosphere assuming radio occultation measurement by small satellites (2019)
  • Author(s): Abe, M., N. Sugimoto, Y. Kikuchi, A. Hosono, H. Ando, M. Takagi, I. Garate-Lopez, S. Lebonnois, and C. Ao
  • Organizer: JpGU 2019
  • Int'l Joint Research
• [Presentation] Thermal-tides structure at the cloud level of Venus derived from Akatsuki/LIR observations (2019)
  • Author(s): Kouyama, T., T. Taguchi, T. Fukuhara, T. Imamura, M. Futaguchi, T. Yamada, M. Akiba, Y.J. Lee, T.M. Sato, S. Murakami, G.L. Hashimoto, T. Satoh, and M. Nakamura
  • Organizer: JpGU Meeting 2019
  • Int'l Joint Research
• [Presentation] Atmospheric super rotation developed in a GCM (AFES-Venus) (2019)
  • Author(s): Sugimoto, N., M. Takagi, Y. Matsuda
  • Organizer: JpGU 2019
  • Int'l Joint Research
• [Presentation] Orographic Gravity Waves in the Venus Atmospheric (2019)
  • Author(s): Suzuki, A., M. Takagi, Y. Maejima, H. Ando, N. Sugimoto, and Y. Matsuda
  • Organizer: JpGU 2019
  • Int'l Joint Research
• [Presentation] Active and inactive behaviors of the planetary-scale waves on Venus cloud top (2019)
  • Author(s): Imai, M., T. Kouyama, Y. Takahashi, T. Horinouchi, T. Imamura, A. Yamazaki, S. Watanabe, M. Yamada, M. Nakamura, and T. Satoh
  • Organizer: JpGU 2019
  • Int'l Joint Research
• [Presentation] Venusian cloud physics investigated by a general circulation model (2019)
  • Author(s): Ando, H., M. Takagi, N. Sugimoto, H. Sagawa, and Y. Matsuda
  • Organizer: International Venus Conference 2019
  • Int'l Joint Research
• [Presentation] Akatsuki (cloud-tracking) and TNG/HARPS-N (Doppler velocimetry) coordinated wind measurements of cloud top Venus' atmosphere (2019)
  • Author(s): Gonsalves, R., P. Machado, T. Widemann, J. Peralta, S. Watanabe, A. Yamakazi, T. Satoh, M. Takagi, K. Ogohara, Y.-J. Lee, H. Avet, and J. Silva
  • Organizer: International Venus Conference 2019
  • Int'l Joint Research
• [Presentation] The study on the reproducibility of cold collar assuming radio occultation measurement by small satellites (2019)
  • Author(s): Hosono, A., N. Sugimoto, M. Abe, Y. Kikuchi, H. Ando, M. Takagi, I. Garate-Lopez, S. Lebonnois, and C. Ao
  • Organizer: International Venus Conference 2019
  • Int'l Joint Research
• [Presentation] Planetary-scale streak structure reproduced in high-resolution simulations of the Venus atmosphere with a low-stability layer (2019)
  • Author(s): Kashimura, H., N. Sugimoto, M. Takagi, Y. Matsuda, W. Ohfuchi, T. Enomoto, K. Nakajima, M. Ishiwatari, T.M. Sato, G.L. Hashimoto, T. Satoh, Y.O. Takahashi, Y.-Y. Hayashi
  • Organizer: International Venus Conference 2019
  • Int'l Joint Research
• [Presentation] Venusian yearly-scale variation of super rotation seen in Akatsuki observations (2019)
  • Author(s): Kouyama, T., T. Horinouchi, T. Imamura, Y.J. Lee, M. Takagi, K. Ogohara, H. Kashimura, S. Murakami, N. Satoh, and M. Imai
  • Organizer: International Venus Conference 2019
  • Int'l Joint Research
• [Presentation] Intense Decadal Variation of Venus' UV Albedo and its Impacts on the Atmosphere (2019)
  • Author(s): Lee Y.J., K.-L. Jessup, S. Perez-Hoyos, D.V. Titov, S. Lebonnois, J. Peralta, T. Horinouchi, T. Imamura, S. Limaye, E. Marcq, M. Takagi, A. Yamazaki, M. Yamada, S. Watanabe, S. Murakami, K. Ogohara, W.M. McClintock, G. Holsclaw, and A. Roman
  • Organizer: International Venus Conference 2019
  • Int'l Joint Research / Invited
• [Presentation] Doppler-wind observations of Venus mesosphere: Comparison with new GCM experiments (2019)
  • Author(s): Sagawa, H., M. Takagi, H. Ando, and G. Gilli
  • Organizer: International Venus Conference 2019
  • Int'l Joint Research
• [Presentation] The Venus AFES LETKF Data Assimilation System (VALEDAS) (2019)
  • Author(s): Sugimoto, N., A. Yamazaki, T. Kouyama, H. Kashimura, T. Enomoto, and M. Takagi
  • Organizer: International Venus Conference 2019
  • Int'l Joint Research
• [Presentation] AFES-project team, Numerical modeling of the Venus atmosphere (2019)
  • Author(s): Takagi, M., N. Sugimoto, H. Ando, H. Kashimura, and Y. Matsuda
  • Organizer: International Venus Conference 2019
  • Int'l Joint Research / Invited
• [Presentation] Continuous monitoring of planetary-scale waves at the Venus cloud top (2019)
  • Author(s): Imai, M., T. Kouyama, Y. Takahashi, S. Watanabe, T. Horinouchi, T. Imamura, A. Yamazaki, M. Yamada, M. Nakamura, and T. Satoh
  • Organizer: International Venus Conference 2019
  • Int'l Joint Research
• [Presentation] Radio occultation observing system simulation experiment of the Venus atmosphere (2019)
  • Author(s): Sugimoto, N., M. Abe, A. Hosono, Y. Kikuchi, H. Ando, M. Takagi, I. Garate-Lopez, S. Lebonnois, C. Ao
  • Organizer: 27th IUGG General Assembly
  • Int'l Joint Research
• [Presentation] Effects of Orographic Gravity Waves on the Venus Atmospheric Super-rotation (2019)
  • Author(s): Suzuki, A., M. Takagi, Y. Maejima, H. Ando, N. Sugimoto, and Y. Matsuda
  • Organizer: AOGS 16th Annual Meeting
  • Int'l Joint Research
• [Presentation] Venusian cloud distribution simulated by a general circulation model (2019)
  • Author(s): Ando, H., M. Takagi, N. Sugimoto, H. Sagawa, and Y. Matsuda
  • Organizer: AOGS 16th Annual Meeting
  • Int'l Joint Research
• [Presentation] Sensitivity variation of ASTER derived from Moon and deepspace observations in 2003 and 2017 (2019)
  • Author(s): Kouyama T., S. Tsuchida, F. Sakuma, T. Tachikawa, H. Yamamoto, K. Obata, S. Kato, M. Kikuchi, R. Nakamura
  • Organizer: 2019 IEEE International Geoscience and Remote Sensing Symposium
  • Int'l Joint Research
• [Presentation] Venusian cloud distribution simulated by a general circulation model (2019)
  • Author(s): Ando, H., M. Takagi, N. Sugimoto, H. Sagawa, and Y. Matsuda
  • Organizer: EPSC-DPS Joint Meeting 2019
  • Int'l Joint Research
• [Presentation] Temporal evolution of the planetary-scale UV feature at the Venusian cloud top observed by Akatsuki/UVI (2019)
  • Author(s): Imai, M., T. Kouyama, Y. Takahashi, A. Yamazaki, S. Watanabe, M. Yamada, T. Imamura, T. Satoh, M. Nakamura, S. Murakami, K. Ogohara, and T. Horinouchi
  • Organizer: EPSC-DPS Joint Meeting 2019
  • Int'l Joint Research
• [Presentation] Doppler wind measurements of Venus upper atmosphere: Comparisons with updated GCM experiments (2019)
  • Author(s): Sagawa, H., G. Gilli, M. Takagi, H. Ando
  • Organizer: EPSC-DPS Joint Meeting 2019
  • Int'l Joint Research
• [Presentation] Mean meridional circulation in the Venus atmosphere (2019)
  • Author(s): Takagi, M., N. Sugimoto, H. Kashimura, H. ANdo, and Y. Matsuda
  • Organizer: EPSC-DPS Joint Meeting 2019
  • Int'l Joint Research
• [Presentation] Impact of data assimilation on thermal tides in the case of Venus Express wind observation (2019)
  • Author(s): Sugimoto, N., T. Kouyama, and M. Takagi
  • Organizer: EPSC-DPS Joint Meeting 2019
  • Int'l Joint Research
• [Presentation] Cloud-top winds obtained from Akatsuki: three-year statistics of mean winds and momentum transport (2019)
  • Author(s): Horinouchi, T., T. Imamura, T. Kouyama, Y.J. Lee, S.S. Limaye, S. Murakami, K. Ogohara, J. Peralta, T. Satoh, M. Takagi, S. Watanabe, M. Yamada, A. Yamazaki
  • Organizer: EPSC-DPS Joint Meeting 2019
  • Int'l Joint Research
• [Presentation] Observing system simulation experiment for radio occultation by small satellites of the Venus atmosphere (2019)
  • Author(s): Sugimoto, N., M. Abe, Y. Kikuchi, A. Hosono, H. Ando, M. Takagi, I. Garate-Lopez, S. Lebonnois, and C. Ao
  • Organizer: EPSC-DPS Joint Meeting 2019
  • Int'l Joint Research
• [Presentation] The feasibility study on radio occultation measurements of the Venus atmosphere among small satellites (2019)
  • Author(s): Abe, M., N. Sugimoto, Y. Kikuchi, A. Hosono, H. Ando, M. Takagi, I. Garate-Lopez, S. Lebonnois, and C.O. Ao
  • Organizer: AGU Fall Meeting 2019
  • Int'l Joint Research
• [Presentation] Comparative analysis of the the Rossby wave at the Venusian cloud top observed by Venus Express/VMC and Akatsuki/UVI (2019)
  • Author(s): 今井正尭, 神山徹, 堀之内武, 渡部重十, 山崎敦, 山田学, 村上真也
  • Organizer: 第146回地球電磁気・地球惑星圏学会秋季講演会
• [Presentation] 大気大循環モデルを用いた金星雲分布の再現 (2019)
  • Author(s): 安藤紘基, 高木征弘, 杉本憲彦, 佐川英夫, 松田佳久
  • Organizer: 第146回地球電磁気・地球惑星圏学会秋季講演会
• [Presentation] LIRで同定された金星における惑星規模大気波動の構造 (2019)
  • Author(s): 神山徹, 今井正尭, 今村剛, 堀之内武, 田口真, 福原哲哉, 佐藤隆雄, 村上真也, はしもとじょーじ, Lee Yeon Joo, 二口将彦, 山田学, 秋場聖浩, 佐藤毅彦, 中村正人
  • Organizer: 第146回地球電磁気・地球惑星圏学会秋季講演会
• [Presentation] 大気大循環モデルを用いた金星雲分布の再現 (2019)
  • Author(s): 安藤紘基, 高木征弘, 杉本憲彦, 佐川英夫, 松田佳久
  • Organizer: 日本気象学会2019年度秋季大会
• [Presentation] 金星探査機 Venus Express の風速データを用いた熱潮汐波への同化インパクトの研究 (2019)
  • Author(s): 杉本憲彦, 神山徹, 高木征弘
  • Organizer: 日本気象学会2019年度秋季大会
• [Funded Workshop] Workshop for Venus modelling and observations 2020 in collaboration between AFES-Venus and LMD/GCM teams (2020)
• [Funded Workshop] Workshop for Venus modelling and observations in collaboration between AFES-Venus and Lisboa teams (2020)