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| Li, Chen; Jian, Zhimin; Jia, Guodong; Dang, Haowen; Wang, Jianxin. |
| Marine nitrogen fixation contributes to the budget of biologically available N, thus fuels phytoplankton productivity and carbon cycle through biological pump. Modern N‐fixation rates are proved to be constrained by oceanographic condition and nutrient supply to the surface waters. However, the paleoceanographic reconstruction of N‐fixation and its regulation mechanism remain highly uncertain in many regions. Here we present records of N‐fixation changes in the South China Sea (SCS) over the past 250,000 years reconstructed by compound‐specific nitrogen isotopes of individual amino acids. The δ15N of source amino acids (δ15NSrc), reflecting the δ15N of the substrate nitrate originating from the subsurface water, is distinctly lower during interglacial... |
| Tipo: Text |
Palavras-chave: Compound-specific delta N-15; Upper water structure; Bulk sedimentary delta N-15; Nitrogen fixation; Orbital time scale; South China Sea. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00509/62061/66237.pdf |
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| Yu, Hua; Liu, Zhenxia; Berne, Serge; Jia, Guodong; Xiong, Yingqian; Dickens, Gerald R.; Wei, Gangjian; Shi, Xuefa; Liu, J. Paul; Chen, Fajin. |
| East China Sea (ECS) is an important climate modulator of East Asia. In the last glacial period, the global sea level, the path and strength of the Kuroshio Current experienced great changes; combined with the variable volume of fresh run-off input, they made the hydrographic situation in the ECS quite different from nowadays. Based on high-resolution alkenone-sea surface temperature (SST) and oxygen isotope composition of planktonic foraminifera Globigerinoides sacculifer we reconstructed paleo-sea surface salinity (SSS) of a long piston core DGKS9604 retrieved from the middle Okinawa Trough of the eastern ECS. The delta O-18 and SST records display significant variations with global ice volume. Synchrony of the millennial-scale climate events like YD and... |
| Tipo: Text |
Palavras-chave: Sea surface salinity; Sea surface temperature; East Asian monsoon; Kuroshio Current; Okinawa Trough; East China Sea. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-7398.pdf |
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| Jia, Guodong; Li, Zhiyang. |
| A sedimentary delta(15)N record in the equatorial western Pacific (WP) shows glacial-interglacial variability from 6.2 to 11.2 parts per thousand during the last two climatic cycles, similar to the denitrification record in the eastern tropical Pacific (ETP). Contrastively, a record in the South China Sea (SCS) exhibits less changes from 4.4 to 6.4 parts per thousand and is quite alike previously published results in marginal seas in the WP. By ruling out several possible causes for the delta(15)N variability, the delta(15)N record in the equatorial WP is interpreted as the source nitrate delta(15)N signals advected from the ETP. Comparison of several delta(15)N records for the last 25 ka distributed in the WP brings out a pattern of northward decrease in... |
| Tipo: Text |
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| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00226/33770/32594.pdf |
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