Preliminary result of dissolved organic radiocarbon in the western North Pacific Ocean

Tanaka, Takayuki; Otosaka, Shigeyoshi  ; Wakita, Masahide*; Amano, Hikaru*; Togawa, Orihiko 

Dissolved organic carbon (DOC) in seawater is one of the largest reservoirs of organic matter on the earth's surface, holding approximately as much carbon as available in atmospheric CO. As a result of the huge carbon reservoir, the role and dynamics of DOC have become of greater interest in the global carbon cycle. It has been suggested that dissolved organic radiocarbon (C-DOC) in seawater is a powerful tool to understand the dynamics of DOC and its researches have been carried out using AMS. However, there are very few data in the world oceans because of the difficulties of the measurement technique. Although it has been represented that the western North Pacific plays an important role in the carbon cycle from the viewpoint of a terminal of the deep water circulation in the world oceans and a high biological activity, C-DOC has not been measured yet. In this study, we obtained its vertical profile in the western North Pacific for the first time.