Akatsuki LIR observing system simulation experiments evaluated by thermal tides in the Venus atmosphere

Norihiko Sugimoto, Yukiko Fujisawa, Nobumasa Komori, Hiroki Ando, Toru Kouyama, Masahiro Takagi

Research output: Contribution to journalArticlepeer-review


Impacts of temperature assimilation on Venusian thermal tides are investigated by the observing system simulation experiments assuming Akatsuki Longwave Infrared Camera (LIR) observations. Synthetic temperature data are prepared by a Venusian general circulation model (VGCM) to test if LIR temperature data resolves a discrepancy in the structure of thermal tides between observations and the VGCM. They are assimilated at 70 km altitude with several combinations of frequency and horizontal region. The result shows that the three-dimensional structure of thermal tides is significantly improved not only in temperature but also in horizontal wind, even if observations are available only at a limited frequency of 6-hourly or on the dayside. The zonal–mean zonal wind and temperature fields are also modified at 60–80 km altitudes globally through the vertical momentum transport of thermal tides. It would be promising to assimilate Akatsuki LIR observations to produce realistic objective analysis of the Venus atmosphere.

Original languageEnglish
Article number44
JournalGeoscience Letters
Issue number1
Publication statusPublished - 2022 Dec


  • Akatsuki
  • GCM
  • LETKF data assimilation
  • Thermal tides
  • Venus atmosphere

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)


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