Millennial-scale variations in sedimentary oxygenation in the western subtropical North Pacific and its links to North Atlantic climate
Millennial-scale variations in sedimentary oxygenation in the western subtropical North Pacific and its links to North Atlantic climate
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西副热带北太平洋沉积物氧化的千年尺度变化及其与北大西洋气候的联系
DOI：
10.5194/cp-16-387-2020
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发表时间：
2020-02
影响因子：
4.3
通讯作者：
Tiedemann Ralf
中科院分区：
文献类型：
--
作者：
Zou Jianjun;Shi Xuefa;Zhu Aimei;K;asamy Selvaraj;Gong Xun;Lembke-Jene Lester;Chen Min-Te;Wu Yonghua;Ge Shulan;Liu Yanguang;Xue Xinru;Lohmann Gerrit;Tiedemann Ralf
深海碳循环，特别是碳固存和释气，是解释千年和轨道时间尺度上大气CO2浓度变化的机制之一。然而，亚热带北太平洋地下沃茨在千年时间尺度上调节大气CO2水平的潜在作用受到很大限制。由于生物泵的作用，冰川深海中呼吸的CO2浓度的增加通常对应于海洋内部的脱氧。因此，这种联系提供了一个机会，研究海洋通风和同时代的出口生产力的基础上氧化还原控制的沉积地球化学参数。在这里，我们调查了一套地球化学指标的沉积物芯从冲绳海槽了解沉积氧的变化在亚热带北太平洋在过去的50万年（50 ka）。我们的研究结果表明，增强中深度西副热带北太平洋（WSTNP）沉积氧发生在寒冷的间隔和8.5万年后，而氧减少在博林Allerod（B/A）和Preboreal。在寒冷时期的增强氧化与北太平洋中层水（NPIW），而8.5万年后的间冰期增加与黑潮电流的加强，由于加强东北信风在热带地区。Heinrich Stadial 1（HS 1）期间NPIW的增强形成可能是由高纬度北太平洋海冰形成和海面盐度振荡的扰动驱动的。由于NPIW形成减少和出口产量增加，B/A期间沉积物氧化减少，表明北太平洋氧气最小区的扩大和中深度沃茨CO2封存增强，沿着大气CO2浓度增加的终止。我们将千年尺度的变化归因于冰消期寒冷和温暖间隔期间NPIW的增强和深渊冲洗的增强，分别与北大西洋深水形成的变化密切相关。
The deep-ocean carbon cycle, especially carbon sequestration and outgassing, is one of the mechanisms to explain variations in atmospheric CO2 concentrations on millennial and orbital timescales. However, the potential role of subtropical North Pacific subsurface waters in modulating atmospheric CO2 levels on millennial timescales is poorly constrained. An increase in the respired CO2 concentration in the glacial deep-ocean due to biological pump generally corresponds to deoxygenation in the ocean interior. This link thus offers a chance to study oceanic ventilation and coeval export productivity based on redox-controlled sedimentary geochemical parameters. Here, we investigate a suite of geochemical proxies in a sediment core from the Okinawa Trough to understand sedimentary oxygenation variations in the subtropical North Pacific over the last 50 000 years (50 ka). Our results suggest that enhanced mid-depth western subtropical North Pacific (WSTNP) sedimentary oxygenation occurred during cold intervals and after 8.5 ka, while oxygenation decreased during the Bolling-Allerod (B/A) and Preboreal. The enhanced oxygenation during cold spells is linked to the North Pacific Intermediate Water (NPIW), while interglacial increase after 8.5 ka is linked to an intensification of the Kuroshio Current due to strengthened northeast trade winds over the tropics. The enhanced formation of the NPIW during Heinrich Stadial 1 (HS1) was likely driven by the perturbation of sea ice formation and sea surface salinity oscillations in the high-latitude North Pacific. The diminished sedimentary oxygenation during the B/A due to a decreased NPIW formation and enhanced export production, indicates an expansion of the oxygen minimum zone in the North Pacific and enhanced CO2 sequestration at mid-depth waters, along with the termination of atmospheric CO2 concentration increase. We attribute the millennial-scale changes to an intensified NPIW and enhanced abyss flushing during deglacial cold and warm intervals, respectively, closely related to variations in North Atlantic Deep Water formation.
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影响因子：
--
作者：
G. Lohmann;L. Lembke‐Jene;R. Tiedemann;X. Gong;P. Scholz;J. Zou;Xuefa Shi
通讯作者：
G. Lohmann;L. Lembke‐Jene;R. Tiedemann;X. Gong;P. Scholz;J. Zou;Xuefa Shi
影响因子：
18.3
作者：
Xu Zhang;G. Knorr;G. Lohmann;S. Barker
通讯作者：
Xu Zhang;G. Knorr;G. Lohmann;S. Barker
追踪元古代海洋的逐步氧化过程
影响因子：
64.8
作者：
Scott, C.;Lyons, T. W.;Anbar, A. D.
通讯作者：
Anbar, A. D.
影响因子：
5
作者：
T. Nameroff;L. Balistrieri;J. Murray
通讯作者：
T. Nameroff;L. Balistrieri;J. Murray
影响因子：
16.6
作者：
Clemens SC;Holbourn A;Kubota Y;Lee KE;Liu Z;Chen G;Nelson A;Fox-Kemper B
通讯作者：
Fox-Kemper B