A methodology is proposed using altimter-derived upper layer thickness and baroclinic transport to identify the Kuroshio Extension, the Bifurcation Point and the Northern Branch, by combining TOPEX/POSEIDON altimeter and climatological data within a two-layer reduced gravity model. Results obtained from the Japanese coast to 175 ¿W show that the location of the Bifurcation Point presents interannual variability that is related with upstream conditions. The longitude of the Bifurcation Point ranged from 147 to 160 ¿E. Estimates of baroclinic transport at the Kuroshio Extension and its Northern Branch decrease steadily to the east trough the region of study from 35 to 11 and from 10 to 3 Sv, respectively. ¿ 2001 American Geophysical Union