TY - JOUR
T1 - Zn elemental and isotopic features in sinking particles of the South China Sea
T2 - Implications for its sources and sinks
AU - Liao, Wen Hsuan
AU - Takano, Shotaro
AU - Tian, Hung An
AU - Chen, Hung Yu
AU - Sohrin, Yoshiki
AU - Ho, Tung Yuan
N1 - Funding Information:
We acknowledge the personnel of TORI for deploying and recovering the sediment trap mooring system, especially to S.-H. Ho, B.-S. Wang, F. Kuo, C.-J. Tseng, and H.-L. Lin. We thank the captains and crew of the R/V Ocean Researchers I, III and V for their assistance during the related cruises. We thank W.-C. Tu, C.-C. Hsieh, and K.-F. Huang for their technical support and S.-C. Yang, K.-F. Huang, P. Lam, G.T. F. Wong, and C.-L. Wei for providing helpful comments on this manuscript. We also thank N. Llopis Monferrer for preparing Fig. 5 . We thank two anonymous reviewers and the associate editor, Claudine Stirling, for their constructive comments, which have significantly improved the quality of our manuscript. This study was mainly supported by Taiwan Ministry of Science and Technology grants 105-2119-M-001-039-MY3 and 108-2611-M-001-006-MY3, the Investigator Award of T.-Y. Ho from the Academia Sinica, and partially by ICR-iJURC Short-term Exchange Program to S. Takano, and the International Collaborative Research Program of Institute for Chemical Research, Kyoto University.
Funding Information:
We acknowledge the personnel of TORI for deploying and recovering the sediment trap mooring system, especially to S.-H. Ho, B.-S. Wang, F. Kuo, C.-J. Tseng, and H.-L. Lin. We thank the captains and crew of the R/V Ocean Researchers I, III and V for their assistance during the related cruises. We thank W.-C. Tu, C.-C. Hsieh, and K.-F. Huang for their technical support and S.-C. Yang, K.-F. Huang, P. Lam, G.T. F. Wong, and C.-L. Wei for providing helpful comments on this manuscript. We also thank N. Llopis Monferrer for preparing Fig. 5. We thank two anonymous reviewers and the associate editor, Claudine Stirling, for their constructive comments, which have significantly improved the quality of our manuscript. This study was mainly supported by Taiwan Ministry of Science and Technology grants 105-2119-M-001-039-MY3 and 108-2611-M-001-006-MY3, the Investigator Award of T.-Y. Ho from the Academia Sinica, and partially by ICR-iJURC Short-term Exchange Program to S. Takano, and the International Collaborative Research Program of Institute for Chemical Research, Kyoto University.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/12/1
Y1 - 2021/12/1
N2 - We determined the elemental and isotopic composition of Zn in sinking particles collected in the deep water of the northern South China Sea (NSCS) to investigate the relative contribution of various sources and assess their isotopic signatures. Using differentiable elemental ratios and δ66Zn of the potential sources, a mass balance approach estimates that anthropogenic aerosol Zn accounted for 64 ± 10% of the total Zn in sinking particles for more than 50% of the sampling period, indicating that anthropogenic aerosol Zn has become a dominant form of Zn source in the deep water. A relatively large discrepancy between the estimated and measured δ66Zn is observed during the high productivity season, which can be attributed to the elevated contribution of the biogenic hard parts or scavenging Zn on organic materials. Elevated δ66Zn values were observed at 3500 m during autumn which may be caused by the influence of authigenic particles during the lowest flux period. We found that the averaged measured output δ66Zn value, +0.35 ± 0.12‰, is significantly lighter than most of the output values proposed in previous studies. Due to recent findings highlighting the importance of anthropogenic aerosol Zn in the ocean, we have re-evaluated the solubility and fluxes of aerosol Zn in the ocean and found that the flux has been significantly underestimated in previous studies. The updated global aerosol Zn input to the ocean, ranging from 0.3 to 3.0 Gmol yr−1, is comparable to the output magnitude from hydrothermal and riverine sources. The updated Zn residence time would then be down to 1400 years on average. In addition to organic decomposition, the sinking particle data indicate that particle-associated removal and release processes play important roles in controlling Zn cycling in the water column. How anthropogenic aerosol deposition influences Zn fluxes and cycling in other oceanic regions deserves further investigation.
AB - We determined the elemental and isotopic composition of Zn in sinking particles collected in the deep water of the northern South China Sea (NSCS) to investigate the relative contribution of various sources and assess their isotopic signatures. Using differentiable elemental ratios and δ66Zn of the potential sources, a mass balance approach estimates that anthropogenic aerosol Zn accounted for 64 ± 10% of the total Zn in sinking particles for more than 50% of the sampling period, indicating that anthropogenic aerosol Zn has become a dominant form of Zn source in the deep water. A relatively large discrepancy between the estimated and measured δ66Zn is observed during the high productivity season, which can be attributed to the elevated contribution of the biogenic hard parts or scavenging Zn on organic materials. Elevated δ66Zn values were observed at 3500 m during autumn which may be caused by the influence of authigenic particles during the lowest flux period. We found that the averaged measured output δ66Zn value, +0.35 ± 0.12‰, is significantly lighter than most of the output values proposed in previous studies. Due to recent findings highlighting the importance of anthropogenic aerosol Zn in the ocean, we have re-evaluated the solubility and fluxes of aerosol Zn in the ocean and found that the flux has been significantly underestimated in previous studies. The updated global aerosol Zn input to the ocean, ranging from 0.3 to 3.0 Gmol yr−1, is comparable to the output magnitude from hydrothermal and riverine sources. The updated Zn residence time would then be down to 1400 years on average. In addition to organic decomposition, the sinking particle data indicate that particle-associated removal and release processes play important roles in controlling Zn cycling in the water column. How anthropogenic aerosol deposition influences Zn fluxes and cycling in other oceanic regions deserves further investigation.
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U2 - 10.1016/j.gca.2021.09.013
DO - 10.1016/j.gca.2021.09.013
M3 - Article
AN - SCOPUS:85116004258
SN - 0016-7037
VL - 314
SP - 68
EP - 84
JO - Geochimica et Cosmochimica Acta
JF - Geochimica et Cosmochimica Acta
ER -