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

Radiocarbon in dissolved organic matter in seawater gives information on the dynamics and origin of the dissolved organic matter. Here, we present the vertical profile of Delta C-14 of dissolved organic carbon in the western North Pacific Ocean. The profile was almost parallel to that for Delta C-14 of dissolved inorganic carbon, indicating that the time scale of seawater circulation was the main influence on the Delta C-14 signature of dissolved organic carbon. On the basis of the Delta C-14 differences between dissolved organic carbon and dissolved inorganic carbon, and a comparison with Delta C-14 of dissolved organic carbon in the central North Pacific Ocean, we suggest that there may be a source of younger dissolved organic carbon in the western North Pacific Ocean. (C) 2009 Elsevier B.V. All rights reserved.