Thermal response of the bottom pressure sensor off the coast of the Tokai District, Central Honshu and its application to oceanographic analysis.

Abstract

Thermal response of the telemetry bottom pressure sensor 100 km off the south coast of the Tokai District, central Honshu, is analyzed. It is shown, through the analysis, that there appear comparatively large (approximately 0.1°C) short-period bottom temperature changes at the rate of once per several months even just above the seabed 2200 m deep. At these times, the tidal residuals of bottom pressure have a tendency to show characteristic short-term changes of durations of ten days or more and amplitude less than 10 cmH2O. It is possibly due to mesoscale ocean eddies. The bottom variations of this temperature and pressure are compared with the oceanographic conditions, especially with the route of the Kuroshio, and some qualitative correlation is observed among them. Thus, it could be concluded that the bottom pressure records are applicable as an indicator for oceanographic variations off the Tokai District.