Improvement of photochemical extraction system for radiocarbon study of dissolved organic carbon in the central Pacific Ocean

Jeon, H.; Otosaka, Shigeyoshi; Yamashita, Yohei*; Ogawa, Hiroshi*

no journal, , 

The ocean is a huge reservoir of dissolved organic carbon that contains almost the same amount of carbon in the atmosphere. Radiocarbon signatures of dissolved organic carbon (DOC) in seawater can provide useful information on how organic carbon is produced, transported, and ultimately sequestered in the ocean's interior. In order to measure radiocarbon contents of seawater samples, they should be processed with a specific preparation system consists of the custom quartz reactor, dedicated vacuum line and UV lamp followed by radiocarbon counting with an accelerator mass spectrometer. As the first step of the study, we developed the irradiation procedure using a low-pressure Hg lamp and an oxidation catalyst. We present here not only how the system is progressing but also what radiocarbon study in the central Pacific Ocean means for better understanding of oceanic carbon cycle.