Recent observations done by the ASUKA (Affiliated Surveys of the Kuroshio off Cape Ashizuri) Group provided a time series of
the Kuroshio volume transport for 7 years
(Imawaki et al. 1997; Imawaki et al. 2000; see Fig.1 for the location of the
observation line). As shown in Fig.2, Averaged
annual range of the volume transport variation
is estimated to be about 10 Sv, which is
much smaller than that of the Sverdrup transport
at the southernmost point.
In the present study, a two-layer numerical
model driven by the wind stress is used to
explain the observed annual variation of
the Kuroshio transport south of Japan. Special
attention is given to the effect of a ridge,
representing the Izu-Ogasawara Ridge, on
the generation of the baroclinic activity
through the coupling of the barotropic and
baroclinic modes of motion.
