Impact of Data Assimilation on Thermal Tides in the Case of Venus Express Wind Observation

Norihiko Sugimoto, Toru Kouyama, Masahiro Takagi

Research output: Contribution to journalArticle

Abstract

Impacts of horizontal winds assimilation on thermal tides are investigated by using the Venus atmospheric general circulation model for the Earth Simulator local ensemble transform Kalman filter data assimilation system. The assimilated data are horizontal winds derived from Venus ultraviolet images taken by the Venus Monitoring Camera onboard the Venus Express orbiter. The results show that three-dimensional structures of the thermal tides are significantly improved not only in the horizontal winds but also in the temperature field, even though the observations are available only at the cloud top level on the southern dayside hemisphere approximately once an Earth day. The reproduced temperature fields agree well with recent radio occultation measurements of the Venus Climate Orbiter Akatsuki. The zonal mean fields of the zonal wind and temperature are also improved globally. This study would enable reanalysis of past Venus observations.

Original languageEnglish
JournalGeophysical Research Letters
DOIs
Publication statusPublished - 2019 Jan 1

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Keywords

  • GCM
  • LETKF data assimilation
  • thermal tides
  • Venus atmosphere
  • Venus Express

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)

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