New Insight Into the Source and Sink of 227Ac in the Ocean
Abstract Actinium‐227 (227Ac) has been used as a powerful tracer of diapycnal mixing in the ocean, assuming that it is conservative and originates mainly from deep‐sea sediments. However, here we show an unexpectedly large source (continental margin) and sink (scavenging) of 227Ac in the ocean, base...
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Wiley
2024-01-01
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| Series: | Geophysical Research Letters |
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| Online Access: | https://doi.org/10.1029/2023GL105853 |
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| author | Hojong Seo Hanbyul Lee Guebuem Kim |
| author_facet | Hojong Seo Hanbyul Lee Guebuem Kim |
| author_sort | Hojong Seo |
| collection | DOAJ |
| description | Abstract Actinium‐227 (227Ac) has been used as a powerful tracer of diapycnal mixing in the ocean, assuming that it is conservative and originates mainly from deep‐sea sediments. However, here we show an unexpectedly large source (continental margin) and sink (scavenging) of 227Ac in the ocean, based on high‐resolution 227Ac distributions obtained for the first time by mooring Mn‐fibers in the East Sea (Japan Sea). Although we expected a decrease in radium‐228 (228Ra) to 227Ac ratios with depth owing to their different half‐lives, the ratios increased with depth in the upper layer, indicating efficient removal of 227Ac by particle scavenging. In addition, unusually high 227Ac activities (∼15 dpm m−3) were observed in the surface layer, likely due to the horizontal transport of 227Ac‐enriched shelf water. Thus, our results suggest refining our understanding of the geochemical cycle and application of 227Ac in the ocean. |
| format | Article |
| id | doaj-art-b036af60ae9147688dc17d6cb225b5df |
| institution | OA Journals |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2024-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-b036af60ae9147688dc17d6cb225b5df2025-08-20T02:11:09ZengWileyGeophysical Research Letters0094-82761944-80072024-01-01512n/an/a10.1029/2023GL105853New Insight Into the Source and Sink of 227Ac in the OceanHojong Seo0Hanbyul Lee1Guebuem Kim2School of Earth and Environmental Sciences Research Institute of Oceanography Seoul National University Seoul KoreaSchool of Earth and Environmental Sciences Research Institute of Oceanography Seoul National University Seoul KoreaSchool of Earth and Environmental Sciences Research Institute of Oceanography Seoul National University Seoul KoreaAbstract Actinium‐227 (227Ac) has been used as a powerful tracer of diapycnal mixing in the ocean, assuming that it is conservative and originates mainly from deep‐sea sediments. However, here we show an unexpectedly large source (continental margin) and sink (scavenging) of 227Ac in the ocean, based on high‐resolution 227Ac distributions obtained for the first time by mooring Mn‐fibers in the East Sea (Japan Sea). Although we expected a decrease in radium‐228 (228Ra) to 227Ac ratios with depth owing to their different half‐lives, the ratios increased with depth in the upper layer, indicating efficient removal of 227Ac by particle scavenging. In addition, unusually high 227Ac activities (∼15 dpm m−3) were observed in the surface layer, likely due to the horizontal transport of 227Ac‐enriched shelf water. Thus, our results suggest refining our understanding of the geochemical cycle and application of 227Ac in the ocean.https://doi.org/10.1029/2023GL105853actinium‐227continental shelf waterparticle scavengingEast Sea (Japan Sea)mooring Mn‐fibers |
| spellingShingle | Hojong Seo Hanbyul Lee Guebuem Kim New Insight Into the Source and Sink of 227Ac in the Ocean Geophysical Research Letters actinium‐227 continental shelf water particle scavenging East Sea (Japan Sea) mooring Mn‐fibers |
| title | New Insight Into the Source and Sink of 227Ac in the Ocean |
| title_full | New Insight Into the Source and Sink of 227Ac in the Ocean |
| title_fullStr | New Insight Into the Source and Sink of 227Ac in the Ocean |
| title_full_unstemmed | New Insight Into the Source and Sink of 227Ac in the Ocean |
| title_short | New Insight Into the Source and Sink of 227Ac in the Ocean |
| title_sort | new insight into the source and sink of 227ac in the ocean |
| topic | actinium‐227 continental shelf water particle scavenging East Sea (Japan Sea) mooring Mn‐fibers |
| url | https://doi.org/10.1029/2023GL105853 |
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