Decadal Changes in Bomb-Produced Radiocarbon in the Pacific Ocean from the 1990s to 2000s
| Autor: | Yuichiro Kumamoto, Takeshi Kawano, Akihiko Murata, Shuichi Watanabe, Masao Fukasawa |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
010506 paleontology
Archeology 010504 meteorology & atmospheric sciences Subtropics 01 natural sciences Subarctic climate Pacific ocean law.invention Turnover time Oceanography law Dissolved organic carbon General Earth and Planetary Sciences Radiocarbon dating Thermocline World Ocean Circulation Experiment Geology 0105 earth and related environmental sciences |
| Zdroj: | Radiocarbon. 55:1641-1650 |
| ISSN: | 1945-5755 0033-8222 |
| Popis: | In the 2000s, radiocarbon in dissolved inorganic carbon was measured during 7 revisit cruises along the lines of the World Ocean Circulation Experiment in the Pacific Ocean. Comparison of 14C data along these lines from the 1990s and 2000s revealed decadal changes of 14C concentration in the thermocline, most of which were due to temporal changes in the bomb-produced 14C. Vertical profiles and vertical-integrated inventories of the bomb 14C in the subarctic and equatorial regions did not change appreciably. In the southern subtropical region, 14C decreased in the upper thermocline from the surface to ∼500 m depth. In contrast, 14C increased in the lower thermocline below ∼500 m depth. The opposing directions in 14C change resulted in small temporal changes in the total inventory of bomb 14C. On the other hand, the water-column inventory significantly decreased in the northwestern subtropical region due to the 14C decrease in the upper thermocline. These decadal changes in bomb 14C indicate that the turnover time of thermocline circulation in the northwestern subtropical region is faster than that in the southern subtropical region, and imply an interbasin transport of bomb 14C from the North Pacific to other basins. |
| Databáze: | OpenAIRE |
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