Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1073/pnas.1905553116 |
Fundamentally different global marine nitrogen cycling in response to severe ocean deoxygenation | |
B. David A. Naafs; Fanny M. Monteiro; Ann Pearson; Meytal B. Higgins; Richard D. Pancost; and Andy Ridgwell | |
2019 | |
发表期刊 | Proceedings of the National Academy of Sciences of the United States of America |
ISSN | 0027-8445 |
出版年 | 2019 |
卷号 | 116期号:50页码:24979-24984 |
语种 | 英语 |
英文摘要 | AbstractThe present-day marine nitrogen (N) cycle is strongly regulated by biology. Deficiencies in the availability of fixed and readily bioavailable nitrogen relative to phosphate (P) in the surface ocean are largely corrected by the activity of diazotrophs. This feedback system, termed the “nitrostat,” is thought to have provided close regulation of fixed-N speciation and inventory relative to P since the Proterozoic. In contrast, during intervals of intense deoxygenation such as Cretaceous ocean anoxic event (OAE) 2, a few regional sedimentary δ15N records hint at the existence of a different mode of marine N cycling in which ammonium plays a major role in regulating export production. However, the global-scale dynamics during this time remain unknown. Here, using an Earth System model and taking the example of OAE 2, we provide insights into the global marine nitrogen cycle under severe ocean deoxygenation. Specifically, we find that the ocean can exhibit fundamental transitions in the species of nitrogen dominating the fixed-N inventory––from nitrate (NO3−) to ammonium (NH4+)––and that as this transition occurs, the inventory can partially collapse relative to P due to progressive spatial decoupling between the loci of NH4+ oxidation, NO3− reduction, and nitrogen fixation. This finding is relatively independent of the specific state of ocean circulation and is consistent with nitrogen isotope and redox proxy data. The substantive reduction in the ocean fixed-N inventory at an intermediate state of deoxygenation may represent a biogeochemical vulnerability with potential implications for past and future (warmer) oceans. |
英文关键词 | nitrogen ocean OAE Cretaceous anthropogenic |
领域 | 地球科学 ; 气候变化 ; 资源环境 |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/232539 |
专题 | 地球科学 资源环境科学 气候变化 |
推荐引用方式 GB/T 7714 | B. David A. Naafs,Fanny M. Monteiro,Ann Pearson,et al. Fundamentally different global marine nitrogen cycling in response to severe ocean deoxygenation[J]. Proceedings of the National Academy of Sciences of the United States of America,2019,116(50):24979-24984. |
APA | B. David A. Naafs,Fanny M. Monteiro,Ann Pearson,Meytal B. Higgins,Richard D. Pancost,&and Andy Ridgwell.(2019).Fundamentally different global marine nitrogen cycling in response to severe ocean deoxygenation.Proceedings of the National Academy of Sciences of the United States of America,116(50),24979-24984. |
MLA | B. David A. Naafs,et al."Fundamentally different global marine nitrogen cycling in response to severe ocean deoxygenation".Proceedings of the National Academy of Sciences of the United States of America 116.50(2019):24979-24984. |
条目包含的文件 | 条目无相关文件。 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。
修改评论