Drift simulation with particular regard to that associated with the 3.11 tsunami

Kawamura, Hideyuki  ; Kobayashi, Takuya 

A drift simulation on the movement of the tsunami debris was carried out to examine the positions in the North Pacific after the Great East Japan Earthquake occurred on March 11, 2011. We carried out a hindcast experiment from March 2011 to August 2013 using the accurate input data reanalyzed through a three-dimensional variational data assimilation. A forecast experiment from September 2013 to May 2016 followed the hindcast experiment using the input data forecasted by a four-dimensional variational data assimilation system. It is suggested that the tsunami debris was mainly transported eastward by the Kuroshio Extension. The positions and date to wash ashore on the coast of the North American Continent depended on a kind of tsunami debris, because the tsunami debris floating over the sea surface is largely affected by the ocean surface wind. The tsunami debris in the vicinity of the North American Continent inclined to migrate southwestward.