Marine Environmental Prediction Laboratory

Our research group has conducted numerous field observations in the East China Sea to elucidate the ocean circulation, using acoustic Doppler current profiles, satellite-track drifters and so forth. In addition, using a numerical ocean-circulation model validated with these observed dataset, we have elucidated various physical processes over the Yellow Sea and East China Sea shelves: for instance, about 70 % of Changjiang-derived fresh water is carried into the Japan Sea by ocean currents over the East China Sea shelf (Isobe et a., 2002, JGR; Chang and Isobe, 2003, JGR). In addition, Kuroshio frontal waves at the shelf break lead to about 0.85*106 m3/s of seawater exchange between the Kuroshio and East China Sea shelf (Isobe and Beardsley, 2006, JGR). Recently, using this numerical ocean-circulation model, we are trying to forecast and/or hindcast behavior of marine litter and giant jerryfish drifting in East China Sea.

   In addition to the above ocean-circulation model, we have constructed material-transport models with various biochemical processes in the study areas for hindcasting and forecasting the fates of non-conservative chemicals such as nutrients and marine pollutants.

Furthermore, the ocean-circulation model is improved in various ways in our laboratory. For instance, using finite volume ocean models with unstructured triangle cell grids (e.g., FVCOM; Chen et al., 2003, JAOT), the ocean circulation is likely to be reproduced much more accurately in coastal and shelf waters having a complicated topography. Our goal is to establish ocean-dynamics theories and reliable numerical models for hindcasting and/or forecasting the ocean circulation and its related material transports in shallow coastal and shelf waters such as the Seto-Inland Sea and the East China Sea.