Modeling the drift of Japan Tsunami Marine Debris (JTMD); An Application of high computing simulation and data assimilation

Kamachi, Masafumi*; Ishikawa, Yoichi*; Kawamura, Hideyuki ; Maximenko, N.*; Hafner, J.*; MacFadyen, A.*

The tsunami that followed the Great East Japan Earthquake in March 2011 caused a large amount of debris to flow out into the North Pacific, mainly from the Tohoku district, Japan. We conducted drift simulations to monitor and predict the trajectory of the tsunami debris. The results suggested that the tsunami debris was mainly transported eastward by the Kuroshio Extension and prevailing westerly winds, spreading in a north-south direction by ocean eddies and storms. As for the tsunami debris with high buoyancy, it was shown to be strongly influenced by ocean surface winds as well as ocean currents, reaching the west coast of the North American continent around the fall of 2011.