Numerical simulation of orographic gravity waves observed over Syowa Station

Masashi Kohma; Kaoru Sato; David C. Fritts; Thomas S. Lund

Presentation information

[E] Oral

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

[A-AS01] Evolution of Global Environmental Research based on Atmospheric Vertical Motions

Sun. May 21, 2023 9:00 AM - 10:15 AM 105 (International Conference Hall, Makuhari Messe)

convener:Masaki Satoh(Atmosphere and Ocean Research Institute, The University of Tokyo), Kaoru Sato(Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo), Yosuke Niwa(National Institute for Environmental Studies), Hajime Okamoto(Kyushu University), Chairperson:Masaki Satoh(Atmosphere and Ocean Research Institute, The University of Tokyo), Kaoru Sato(Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo), Yosuke Niwa(National Institute for Environmental Studies)

10:00 AM - 10:15 AM

[AAS01-05] Numerical simulation of orographic gravity waves observed over Syowa Station

★Invited Papers

*Masashi Kohma¹, Kaoru Sato¹, David C. Fritts², Thomas S. Lund² (1.Department of Earth and Planet Science, Graduate School of Science, The University of Tokyo, 2.GATS )

Keywords:Atmospheric gravity waves, Turbulence, Hydraulic jump, LES, Atmospheric radar

A numerical simulation for gravity waves (GW) observed over Syowa Station on 18 May 2021 is performed using a model with a horizontal/vertical resolution of 250/60 m. The realistic topography and background horizontal winds and temperatures were used in the experiment. The amplitudes of GW fluctuations and momentum flux associated with GW in the lower stratosphere are comparable to those from radar observations. The simulation also shows several interesting aspects of GW including ship-wave pattern resulting from small mountains, GW filtering effect for different horizontal wavenumber vector orientations, turbulence generation around the critical level, surface turbulent wake downwind of a hydraulic jump, and GW radiation from the edge of the turbulent wake.