The composite feature of seasonal change of the Kuroshio speed is shown in Fig. 6. The Kuroshio seems slightly strong in early summer. But it is not significant. On the other hand the Kuroshio was likely to appear more frequently in early summer than the other season.

Fig. 6　Composited time series of the latitude of the Kuroshio core observed (upper panel), and the maximum speed of the Kuroshio (lower panel) as a function of calendar day.

　

Ongoing and near future studies in JAMSTEC

　

1.　Eastern edge of the Izu-Ridge

A field experiment has carried at the Kuroshio counter current region over the Izu Ridge from March 1996 to August 1998. The major objective is to understand the activity and evolution of mesoscale eddies, those are likely to play an important role in the Kuroshio recirculation system.

The observation program includes in site measurements: current meter moorings, 5 set of ocean acoustic tomography moorings, and CTD/XCTD/XBT profiles obtained by research vessels. Other important component is an ADCP system mounted on a new‘Ogasawara Maru’, that has been on service since March 1997.

The data are now being analyzed including the satellite altimetry data. The analyzed procedure, such as data assimilation method is also being developed. This experiment should be one of the feasibility studies for the Kuroshio Extension experiment, shown in next subsection. We have already succeeded to make a good system appropriate for the new ferry and install conditions. This ADCP observation has to be contributed to the TOLEX activities.

BACK　　　CONTENTS　　　NEXT