Japan Geoscience Union Meeting 2024

Presentation information

[J] Oral

A (Atmospheric and Hydrospheric Sciences ) » A-AS Atmospheric Sciences, Meteorology & Atmospheric Environment

[A-AS10] Stratosphere-troposphere (Atmospheric) Processes And their Role in Climate

Tue. May 28, 2024 1:45 PM - 3:15 PM 104 (International Conference Hall, Makuhari Messe)

convener:Nawo Eguchi(Research Institute for Applied Mechanics, Kyushu University), Shunsuke Noguchi(Department of Earth and Planetary Sciences, Faculty of Science, Kyushu University), Yayoi Harada(Meteorological Research Institute), Masakazu Taguchi(Aichi University of Education), Chairperson:Nawo Eguchi(Research Institute for Applied Mechanics, Kyushu University), Masakazu Taguchi(Aichi University of Education)



1:45 PM - 2:00 PM

[AAS10-01] GCM studies on the Venus atmosphre

★Invited Papers

*Norihiko Sugimoto1, Yukiko Fujisawa2, Nobumasa Komori2, Hiroki Ando4, Masahiro Takagi4, Hiroki Kashimura3, Yoshihisa Matsuda5 (1.Keio University, Department of Physics, 2.Keio University, Research and Education Center for Natural Sciences, 3.Kobe University, Graduate School of Science, 4.Kyoto Sangyo University, Faculty of Science, 5.Tokyo Gakugei University, Department of Astronomy and Earth Science)

Keywords:Venus atmosphere, Super rotation, General circulation model, Data assimilation, Atmospheric gravity wave

We have developed the Venusian general circulation model (GCM), AFES-Venus (Atmospheric GCM for the Earth Simulator for Venus) [1, 2] and the data assimilation system based on the Local Ensemble Transform Kalman Filter (LETKF), ALEDAS-V (AFES-LETKF data assimilation system for Venus) [3]. Here, we will introduce important recent results of AFES-Venus and ALEDAS-V.
AFES-Venus reproduced the cold collar in the polar region [4], the planetary-scale streak structure observed by Akatsuki infrared (IR2) camera [5], a fully developed super-rotation [6], and spontaneous gravity waves radiated from the thermal tides [7]. Recently, by improving the profiles of static stability and solar heating, the thermal tides [8] and the planetary-scale short periods (Kelvin and Rossby) waves [9] consistent with observations are reproduced. We also checked how the super-rotation depends on the magnitude of horizontal hyper diffusion with medium and high resolutions [10].
ALEDAS-V improved the horizontal structures of thermal tides with the data assimilation of horizontal winds derived by cloud tracking of ultra-violet images from Venus Express [11] and Akatsuki [12]. Although the observed horizontal winds are limited to low latitudes on the day side, the zonal-mean zonal winds and temperature are also modified globally [12]. We have also conducted observing system simulation experiments (OSSEs) assuming Akatsuki Longwave Infrared Camera (LIR) observations [13].
References: [1] Sugimoto N. et al. (2014) JGR-Planets, 119, 1950–1968. [2] Sugimoto N. et al. (2014) GRL, 41, 7461–7467. [3] Sugimoto N. et al. (2017) Sci. Rep.. 7, 9321. [4] Ando H. et al. (2016) Nature Comm., 7, 10398. [5] Kashimura H. et al. (2019) Nature Comm., 10, 23. [6] Sugimoto N. et al. (2019) GRL, 46, 1776–1784. [7] Sugimoto N. et al. (2021) Nature Comm., 12, 3682. [8] Suzuki A. et al. (2022) JGR-Planets, 127, 7243. [9] Takagi M. et al. (2022) JGR-Planets, 127, 7164. [10] Sugimoto N. et al. (2023) Earth, Planets and Space, 75, 44. [11] Sugimoto N. et al. (2019) GRL, 46, 4573–4580. [12] Fujisawa Y. et al. (2022) Sci. Rep., 12, 14577. [13] Sugimoto N. et al. (2022) Geoscience Lett., 9, 44.