Japan Geoscience Union Meeting 2023

Presentation information

[J] Oral

A (Atmospheric and Hydrospheric Sciences ) » A-CG Complex & General

[A-CG38] Dynamics of Oceanic and Atmospheric Waves, Vortices, and Circulations

Mon. May 22, 2023 10:45 AM - 12:15 PM 102 (International Conference Hall, Makuhari Messe)

convener:Kunihiro Aoki(Meteorological Research Institute, Japan Meteorological Agency), Satoshi Osafune(Japan Agency for Marine-Earth Science and Technology), Yukiharu Hisaki(University of the Ryukyus), Norihiko Sugimoto(Keio University, Department of Physics), Chairperson:Kunihiro Aoki(Japan Meteorological Agency), Satoshi Osafune(Japan Agency for Marine-Earth Science and Technology), Yukiharu Hisaki(University of the Ryukyus), Norihiko Sugimoto(Keio University, Department of Physics)

11:00 AM - 11:15 AM

[ACG38-02] Energetics of the M2 internal tides modulated by typhoons at the Luzon Strait

*Anzhou Cao1,2, Zheng Guo3, Shuya Wang2, Jinbao Song1, Xinyu Guo2 (1.Ocean College, Zhejiang University, 2.Center for Marine Environmental Studies, Ehime University, 3.Marine Science and Technology College, Zhejiang Ocean University)

Keywords:Internal tides, Typhoon Megi, Luzon Strait, Conversion, Baroclinic energy flux, Dissipation

This study investigates the influence of typhoon Megi (2010) on the energetics of the M2 internal tides (ITs) at the Luzon Strait (LS) based on the numerical simulation. Results indicate that typhoon Megi caused intense low-frequency currents and stratification variation near the LS, which further induced significant temporal variations in the M2 conversion, baroclinic energy fluxes and dissipation at the LS. With a condition of no background currents, typhoon Megi reduced the M2 conversion at the LS by 4.5% and weakened the westward M2 baroclinic energy fluxes into the South China Sea by 14.3%. Typhoon Megi did not significantly change the averaged M2 dissipation at the LS, but it elevated the averaged local dissipation efficiency to some extent. When background currents were taken into consideration, the influence of typhoon Megi on the M2 conversion and baroclinic energy fluxes was weakened, but the influence on the M2 dissipation was enhanced. Moreover, idealized experiments indicate that typhoons with different tracks have different influences on the M2 ITs. With the same typhoon characteristics (radius, maximum wind speed and translation speed), the typhoon that passes over the LS from east to west causes the largest variation in the energetics of the M2 ITs at the LS.