論文

査読有り
2018年9月

Local Time Dependence of the Thermal Structure in the Venusian Equatorial Upper Atmosphere: Comparison of Akatsuki Radio Occultation Measurements and GCM Results

Journal of Geophysical Research: Planets
  • Hiroki Ando
  • Masahiro Takagi
  • Tetsuya Fukuhara
  • Takeshi Imamura
  • Norihiko Sugimoto
  • Hideo Sagawa
  • Katsuyuki Noguchi
  • Silvia Tellmann
  • Martin Pätzold
  • Bernd Häusler
  • Yasuhiro Murata
  • Hiroshi Takeuchi
  • Atsushi Yamazaki
  • Tomoaki Toda
  • Atsushi Tomiki
  • Rajkumar Choudhary
  • Kishore Kumar
  • Geetha Ramkumar
  • Maria Antonita
  • 全て表示

123
9
開始ページ
2270
終了ページ
2280
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1029/2018JE005640

©2018. American Geophysical Union. All Rights Reserved. Temperature profiles of the Venus atmosphere obtained by the Akatsuki radio occultation measurements showed a prominent local time dependence above 65-km altitude at low latitudes equatorward of 35°. A zonal wavenumber 2 component is predominant in the temperature field, and its phase (i.e., isothermal) surfaces descend with local time, suggesting its downward phase propagation. A general circulation model (GCM) for the Venus atmosphere, AFES-Venus, reproduced the local time-dependent thermal structure qualitatively consistent with the radio occultation measurements. Based on a comparison between the radio occultation measurements and the GCM results, the observed zonal wavenumber 2 structure is attributed to the semidiurnal tide. Applying the dispersion relationship for internal gravity waves to the observed wave structure, the zonally averaged zonal wind speed at 75- to 85-km altitudes was found to be significantly smaller than that at the cloud top. The decrease of the zonal wind speed with altitude is attributed to the momentum deposition by the upwardly propagating semidiurnal tide excited in the cloud layer.

リンク情報
DOI
https://doi.org/10.1029/2018JE005640
Scopus
https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85055056640&origin=inward
Scopus Citedby
https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85055056640&origin=inward
ID情報
  • DOI : 10.1029/2018JE005640
  • ISSN : 2169-9097
  • eISSN : 2169-9100
  • SCOPUS ID : 85055056640

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