福島第一原発からの放射性核種の初期分散に及ぼす沿岸ジェットとメソスケール渦の影響

抄録

A detailed oceanic downscaling model (Uchiyama et al., 2012) is utilized to better understand the oceanic initial dispersion of the leaked radionuclides during the accident at the Fukushima Daiichi Nuclear Power Plant (1F). Particular attention is paid to the influences of northward geostrophic coastal jet associated with an alongshore high SSH belt peaked at 50 km offshore, and mesoscale eddies shed by the jet in Sendai Bay and by the Kuroshio near the separation point. A spectral coherence analysis exhibits that alongshore wind stress is highly correlated with alongshore current on the shelf over the periods around 168 hours, suggesting that coastally trapped shelf waves are also responsible for the dispersion of the nuclide.