Planetary‐Scale Variations in Winds and UV Brightness at the Venusian Cloud Top: Periodicity and Temporal Evolution

DOI DOI HANDLE Web Site Web Site ほか2件をすべて表示 一部だけ表示 研究データあり 被引用文献17件 参考文献41件 オープンアクセス
  • Masataka Imai
    Artificial Intelligence Research Center Advanced Industrial Science and Technology Tokyo Japan
  • Toru Kouyama
    Artificial Intelligence Research Center Advanced Industrial Science and Technology Tokyo Japan
  • Yukihiro Takahashi
    Planetary and Space Group, Department of Cosmosciences, Graduate School of Science Hokkaido University Sapporo Japan
  • Atsushi Yamazaki
    Institute of Space and Astronautical Science Japan Aerospace Exploration Agency Sagamihara Japan
  • Shigeto Watanabe
    Space Information Center Hokkaido Information University Ebetsu Japan
  • Manabu Yamada
    Planetary Exploration Research Center Chiba Institute of Technology Narashino Japan
  • Takeshi Imamura
    Graduate School of Frontier Sciences The University of Tokyo Kashiwa Japan
  • Takehiko Satoh
    Institute of Space and Astronautical Science Japan Aerospace Exploration Agency Sagamihara Japan
  • Masato Nakamura
    Institute of Space and Astronautical Science Japan Aerospace Exploration Agency Sagamihara Japan
  • Shin‐ya Murakami
    Institute of Space and Astronautical Science Japan Aerospace Exploration Agency Sagamihara Japan
  • Kazunori Ogohara
    School of Engineering The University of Shiga Prefecture Hikone Japan
  • Takeshi Horinouchi
    Faculty of Environmental Earth Science Hokkaido University Sapporo Japan

書誌事項

公開日
2019-10
資源種別
journal article
権利情報
  • http://creativecommons.org/licenses/by/4.0/
DOI
  • 10.1029/2019je006065
  • 10.48550/arxiv.1908.08220
公開者
American Geophysical Union (AGU)

この論文をさがす

説明

<jats:title>Abstract</jats:title><jats:p>Planetary‐scale waves at the Venusian cloud‐top cause periodic variations in both winds and ultraviolet (UV) brightness. While the wave candidates are the 4‐day Kelvin wave and 5‐day Rossby wave with zonal wavenumber 1, their temporal evolutions are poorly understood. Here we conducted a time series analysis of the 365‐nm brightness and cloud‐tracking wind variations, obtained by the UV Imager onboard the Japanese Venus Climate Orbiter Akatsuki from June to October 2017, revealing a dramatic evolution of planetary‐scale waves and corresponding changes in planetary‐scale UV features. We identified a prominent 5‐day periodicity in both the winds and brightness variations, whose phase velocities were slower than the dayside mean zonal winds (or the super‐rotation) by >35 m/s. The reconstructed planetary‐scale vortices were nearly equatorially symmetric and centered at ~35° latitude in both hemispheres, which indicated that they were part of a Rossby wave. The amplitude of wind variation associated with the observed Rossby wave packet was amplified gradually over ~20 days and attenuated over ~50 days. Following the formation of the Rossby wave vortices, brightness variation emerges to form rippling white cloud belts in the 45–60° latitudes of both hemispheres. An ~3.8‐day periodic signals were observed in the zonal wind and brightness variations in the equatorial region before the Rossby wave amplification. Although the amplitude and significance of the 3.8‐day mode were relatively low in the observation season, this feature is consistent with a Kelvin wave, which may be the cause of the dark clusters in the equatorial region.</jats:p>

収録刊行物

被引用文献 (17)*注記

もっと見る

参考文献 (41)*注記

もっと見る

関連プロジェクト

もっと見る

キーワード

問題の指摘

ページトップへ