Open AccessThe Effect of Koshu Seamount on the Formation of the Kuroshio Large Meander South of Japan
Author(s) -
Tatsuo Endoh,
Hiroyuki Tsujino,
Toshiyuki Hibiya
Publication year - 2011
Publication title -
journal of physical oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.706
H-Index - 143
eISSN - 1520-0485
pISSN - 0022-3670
DOI - 10.1175/jpo-d-11-074.1
Subject(s) - seamount , geology , baroclinity , inflow , meander (mathematics) , outflow , instability , trough (economics) , oceanography , mechanics , geometry , physics , mathematics , economics , macroeconomics
Using an inflow–outflow numerical model, the authors demonstrate that the existence of Koshu Seamount, located about 200 km to the south of Cape Shiono-misaki, is essential in creating the large meander (LM) of the Kuroshio. When Koshu Seamount is completely smoothed out, the meander trough propagates away without being amplified to form the LM. In contrast, nearly the same LM as in the case with full topography is formed when the foot of Koshu Seamount remains without being smoothed out and also when the foot of Koshu Seamount is filled in so that the upper part of Koshu Seamount remains. A linear stability analysis applied to the model output shows that the Kuroshio becomes baroclinically most unstable when the water depth decreases offshoreward. The authors therefore conclude that the enhancement of baroclinic instability over the northern slope of Koshu Seamount is a prerequisite to the formation of the LM.