[A-CG40] Dynamics of Oceanic and Atmospheric Waves, Vortices, and Circulations

[ACG40-P08] Dependencies of barotropic channel models on topographic geometries

*Takuro Matsuta¹, Humio Mitsudera² (1.Faculty of Env.Earth Science, Hokkaido University, 2.Institute of Low Temperature Science, Hokkaido University)

Keywords:Antarctic Circumpolar Current, bottom topography, nonlinear response

Since the Antarctic Circumpolar Current (ACC) directly connects the Pacific, Atlantic, and Indian Oceans, the ACC is responsible for the tracer transports in the ocean circulation. The westerly winds that drive the ACC have intensified since the 20th century due to ozone depletion and global warming. Previous studies have suggested that the circumpolar transport is insensitive to westerlies using idealized channel models because the topographic form stress responses to westerlies in a nonlinear manner; however, the dependence of the result on the topographic geometries has been overlooked. In this work, we conducted a series of sensitivity analyses and investigated the dependence on topographic shape, height, and width. We conclude that the dynamics of barotropic channels are strongly constrained by geostrophic contour geometries.