著者

浅野 竜太 磯田 豊 小林 直人 中村 知裕 伊藤 薫

出版者

北海道大学大学院水産科学研究院

雑誌

北海道大学水産科学研究彙報 (ISSN:24353353)

巻号頁・発行日

vol.70, no.1, pp.63-76, 2020-08-24

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A new type of mechanism for the generation of vertical circulation is revealed with the use of numerical experiments for the bended channel model. In the steady passage-flow experiment with a flat bottom and no bottom friction, a remarkable vertical circulation is formed only at the downside of bended corner where a negative horizontal shear flow dominates. Specifically, we call this type circulation “Negative Shear induced Vertical Circulation (NSVC)”, which is caused through the dynamical unbalance of gradient flow and the vorticity balance between the lateral vorticity advection and the sea surface divergence. A field observation was carried out around the Ooma-zaki area in the eastern Tsugaru Strait to confirm an enhanced downward flow expected by the realistic experiment including the bottom slope and friction. The spatial istributions of water temperature support the existence of this downward motion.