Characteristics of planetary-scale waves simulated by a new venusian mesosphere and thermosphere general circulation model

N. Hoshino, H. Fujiwara, M. Takagi, Y. Takahashi, Y. Kasaba

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)

Abstract

We have developed a new general circulation model (GCM) for the venusian mesosphere and thermosphere (80-about 180km). Our GCM simulations show that winds in the subsolar-to-antisolar direction (SS-AS) are predominant above about 90km. A weak return flow of the SS-AS is seen below about 90km. We performed GCM simulations imposing the planetary-scale waves (thermal tides, Rossby wave, and Kelvin wave) at the lower boundary. Although the diurnal and semidiurnal tides are damped below 95km, the Rossby wave propagates up to around 130km. However, the amplitude of the Rossby wave is too small (<1m/s) to affect the general circulation. On the other hand, the Kelvin wave propagates up to about 130km with a maximum zonal wind fluctuation of approximately 5.9m/s on average. The amplitude of the Kelvin wave sometimes exceeds 10m/s around the terminator. The Kelvin wave causes a temporal variation in the wind velocity at the altitude of the O 2-1.27μm nightglow emission (about 95km). Using a newly developed 1-D nightglow model and the composition distribution calculated from our GCM, we investigated the impact of the Kelvin wave on the nightglow distribution. Our results suggest that the Kelvin wave would cause temporal variations in the nightglow emission in the 23:50-00:20LT region with an intensity of 1.1-1.3MR and a period of approximately 4days.

Original languageEnglish
Pages (from-to)818-830
Number of pages13
JournalIcarus
Volume217
Issue number2
DOIs
Publication statusPublished - 2012 Feb

Keywords

  • Atmospheres, dynamics
  • Venus
  • Venus, atmosphere

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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