The changes in the ocean circulation and biological pump played crucial roles in the rise in atmospheric CO2 during the last deglaciation. However, our understanding remains limited regarding which processes―air-sea exchange, ocean circulation, and the biological pump―primarily influence the spatial dynamics of the oceanic carbon cycle. To address this knowledge gap, the present study compiles global stable carbon isotope (δ13C) records from various sources, including shallow and deep planktic, along with epifaunal and infaunal benthic foraminifera. The synthesis reveals a total increase of 0.37 ± 0.05 ‰ in marine δ13C values since the last glacial maximum. Of this increase, 68 ± 5 % is attributed to the response of the oceans in the southern hemisphere, while 32 ± 4 % is attributed to the northern hemisphere. By analyzing the difference between planktic and benthic foraminifera, a decreased vertical δ13C gradient (δ13Csp–sb) is observed during the last deglaciation, indicating rapid carbon exchange between surface and deep waters during deglaciation. Additionally, the offset between the epifaunal and infaunal δ13C (δ13Csb–db) provides insights into changes in productivity and bottom water oxygenation. Overall, the global synthesis suggests that the δ13C variation is largely controlled by ocean circulation in the northern hemisphere and at higher latitudes of the southern hemisphere, while primary production significantly influences subtropical regions. Furthermore, the δ13C confirms that the rise in atmospheric CO2 during the first phase of Heinrich Stadial 1 (HS1) resulted from reduced primary production in subtropical regions along with strong ventilation in the second phase of HS1. Interestingly, the δ13C variations during the Younger Dryas (YD) suggest strong ventilation without evident changes in primary production. This four-dimensional dataset provides valuable insights into the transient changes in the ocean carbon cycle during deglaciation.

中文翻译：

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绘制末次冰川消融期间海洋碳的演变图：δ13C 对冰川消融海洋碳循环的看法


海洋环流和生物泵的变化在上次冰川消融期间大气中 CO2 的增加起了关键作用。然而，对于哪些过程（气海交换、海洋环流和生物泵）主要影响海洋碳循环的空间动力学，我们的理解仍然有限。为了解决这一知识差距，本研究汇编了来自各种来源的全球稳定碳同位素 （δ13C） 记录，包括浅层和深层浮游，以及表层动物和动物群底栖有孔虫。综合显示，自上次冰期最大值以来，海洋 δ13C 值总共增加了 0.37 ± 0.05 ‰。其中，68 ± 5% 归因于南半球海洋的反应，而 32 ± 4% 归因于北半球。通过分析浮游有孔虫和底栖有孔虫之间的差异，在最后一次冰川消融过程中观察到垂直 δ13C 梯度 （δ13Csp-sb） 降低，表明冰川消融期间表层水和深水之间的碳交换迅速。此外，表层动物和动物界 δ13C （δ13Csb–db） 之间的偏移提供了对生产力和底层水氧合变化的见解。总体而言，全球综合表明 δ13C 变化主要受北半球和南半球高纬度地区海洋环流的控制，而初级生产则显着影响亚热带地区。此外，δ13C 证实，海因里希 Stadial 1 （HS1） 第一阶段大气中 CO2 的增加是由于亚热带地区初级产量减少以及 HS1 第二阶段的强烈通风造成的。 有趣的是，年轻树干 （YD） 期间的 δ13C 变化表明通风强烈，初级生产没有明显变化。这个四维数据集为冰川消融过程中海洋碳循环的瞬态变化提供了有价值的见解。