This diminishing of the upper ocean component of the Kuroshio have caused the relative intensification of the deeper layer current, which raised a stronger bottom effect, for the Kuroshio to flow north along the western slop e of the Izu-Ogasawara Ridge, and then to flow south along the eastern slope of the Ridge, as Masuda (1989) demonstrated by barotropic tank model experiment.
It is recently known by observations that there are along-trench flows in the deep layer of this area of the ocean: a southward flow in the western slope and the northward flow in the eastern slope of the tenches (Hallock and Teague, 1996; Fujio et al., 1997; Mitsuzawa and Holloway, 1998), which seem usually independent of the path of the Kuroshio Extension. The above-mentioned relative intensification of the deeper layer current of the Kuroshio and then of the Kuroshio Extension might have raised their stronger interactions with these deep layer flows, and consequently caused the path of the Kuroshio Extension to flow along the eastern slope of the Izu-Ogasawara Trench, resulting in the occurrence of AJI.
The latter half of this study is referred to Toba et al. (1999).
References
Fujio, S., D. Yanagimoto and K. Taira (1997): Flow and characteristics of sea water in the Izu-Ogasawara Trench (II). Book of Abstracts, 1997 Spring Meeting of the Oceanographic Society of Japan, 21. (In Japanese.)
Hallock, Z. R. and W. J. Teague (1996): Evidence for a North Pacific deep western boundary current. J. Geophys. Res. 101, C3, 6617-6624.
Masuda. A (1989): A laboratory experimert on the Kuroshio meander. Deep-Sea Res. 36, 1067-1081.
Mitsuzawa, K. and G. Holloway (1998): Characteristics of deep currents along trenches in the northwest Pacific. J. Geophys. Res. 103, C6 , 13,085-13,092.
Qiu, B., K. A. Kelly and T. M. Joyce (1991): Mean flow and variability in the Kuroshio Extension from Geosat altimetry data. J. Geophys. Res. 96, C10, 18,491-18,507.
Toba, Y. and H. Murakami (1998): Unusual behavior of the Kuroshio Current System from winter 1996 to summer 1997 revealed by ADEOS-OCTS and other data ― Suggestion of topographically forced Alternating-Jet Instability. J. Oceanogr. 54, 465-478.
Toba, Y., H. Murakami, J. Kimura, M. Kim, Y. Yoshikawa and K. Shimada (1999): Unusual behavior of the Kuroshio Current System from winter 1996 to summer 1997 revealed by ADEOS-OCTS and other data (II) ― Investigation from external corditions. To be submitted to J. Oceanogr.
