Japan Geoscience Union Meeting 2021

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[J] Oral

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

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

Sun. Jun 6, 2021 10:45 AM - 12:15 PM Ch.10 (Zoom Room 10)

convener:Yuki Tanaka(Faculty of Marine Science and Technology, Fukui Prefectural University), Kunihiro Aoki(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 Agency for Marine Earth Science and Technology), Yukiharu Hisaki(University of the Ryukyus), Yuki Tanaka(Faculty of Marine Science and Technology, Fukui Prefectural University)

12:00 PM - 12:15 PM

[ACG38-06] Eddy-mean flow interactions and vertical energy redistribution associated with the standing meander in the Antarctic Circumpolar Current

*Takuro Matsuta1, Yukio Masumoto1 (1.Graduate School of Science, The University of Tokyo)


Keywords:eddy-mean flow interactions, Antarctic Circumpolar Current, Lorentz diagram, energy flux

A remarkable feature of the Antarctic Circumpolar Current (ACC) is its insensivity to changes in surface forcing. This feature is explained by balances between a wind-driven overturning circulation and an eddy-driven circulation in the zonally averaged framework. However, the residulal mean theories miss the representation of the ACC's heterogeneity in eddy distributions. Active eddy activities are confined near the vicinity of standing meanders associated with the large topography. In this presentation, local eddy-mean flow interactions are discussed from the Lorentz diargram framework using a realistic eddy-resolution model. Our finding is that large amount of the wind energy input is locally dispersed near the standing meanders through baroclinic instability. Eddy energy is generated in the upper 3000m and dispersed near the bottom. This mismatch between the depth of energy production and dispersion is reconciled by the downward vertical energy flux.