Changes in the geometry of ocean meridional overturning circulation (MOC) are crucial in controlling past changes of climate and the carbon inventory of the atmosphere. However, the accurate timing and global correlation of short-term glacial-to-deglacial changes of MOC in different ocean basins still present a major challenge. The fine structure of jumps and plateaus in atmospheric and planktic radiocarbon (¹⁴C) concentration reflects changes in atmospheric ¹⁴C production, ocean–atmosphere ¹⁴C exchange, and ocean mixing. Plateau boundaries in the atmospheric ¹⁴C record of Lake Suigetsu, now tied to Hulu Cave U∕Th model ages instead of optical varve counts, provide a stratigraphic “rung ladder” of up to 30 age tie points from 29 to 10 cal ka for accurate dating of planktic oceanic ¹⁴C records. The age differences between contemporary planktic and atmospheric ¹⁴C plateaus record the global distribution of ¹⁴C reservoir ages for surface waters of the Last Glacial Maximum (LGM) and deglacial Heinrich Stadial 1 (HS-1), as documented in 19 and 20 planktic ¹⁴C records, respectively. Elevated and variable reservoir ages mark both upwelling regions and high-latitude sites covered by sea ice and/or meltwater. ¹⁴C ventilation ages of LGM deep waters reveal opposed geometries of Atlantic and Pacific MOC. Like today, Atlantic deep-water formation went along with an estuarine inflow of old abyssal waters from the Southern Ocean up to the northern North Pacific and an outflow of upper deep waters. During early HS-1, ¹⁴C ventilation ages suggest a reversed MOC and ∼1500-year flushing of the deep North Pacific up to the South China Sea, when estuarine circulation geometry marked the North Atlantic, gradually starting near 19 ka. High ¹⁴C ventilation ages of LGM deep waters reflect a major drawdown of carbon from the atmosphere. The subsequent major deglacial age drop reflects changes in MOC accompanied by massive carbon releases to the atmosphere as recorded in Antarctic ice cores. These new features of MOC and the carbon cycle provide detailed evidence in space and time to test and refine ocean models that, in part because of insufficient spatial model resolution and reference data, still poorly reproduce our data sets.

中文翻译：

---

大气放射性碳记录的高原和跃变-潜在的起源和价值，作为冰期到冰川期古海洋学的综合年龄标记

海洋子午向翻转环流（MOC）的几何形状变化对于控制过去的气候变化和大气中的碳存量至关重要。但是，不同海盆MOC的短期冰消变化的准确时间和全球相关性仍然是一个重大挑战。大气和板状放射性碳（¹⁴ C）浓度的跃迁和高原的精细结构反映了大气¹⁴ C产生，海洋-大气¹⁴ C 交换和海洋混合的变化。 现已与Hulu Cave U ∕ Th相连的Suigetsu湖大气¹⁴ C记录中的高原边界模型年龄而不是光学阀门计数，提供了一个从29到10 cal ka的多达30个年龄联系点的地层“梯阶”，以精确地记录海洋¹⁴ C记录的年代。如19和20年板块^14所记录的，当代板块高原¹⁴ C和大气¹⁴ C高原之间的年龄差异 记录了最后冰川最大期（LGM）和冰河Heinrich Stadial 1（HS-1）地表水¹⁴ C水库年龄的全球分布。C记录。升高的和变化的储层年龄既标志着上升区，也标志着海冰和/或融水覆盖的高纬度地区。¹⁴ ℃LGM深水的通风年龄揭示了大西洋和太平洋MOC的相反几何形状。像今天一样，大西洋深水的形成伴随着河口的深海老水从南大洋一直流入北太平洋北部，以及上层深水的流出。在HS-1早期，¹⁴ C的通风年龄表明MOC逆转，直到北海深水冲刷到南海至1500年，当时河口环流的几何形状标记了北大西洋，逐渐开始于19 ka附近。高 ¹⁴ CLGM深水的通风年龄反映了大气中碳的大量减少。随后出现的主要冰期年龄下降反映了MOC的变化，伴随南极冰芯中记录的大量碳向大气中的释放。MOC和碳循环的这些新功能为测试和完善海洋模型提供了空间和时间方面的详细证据，部分原因是空间模型的分辨率和参考数据不足，因此仍无法很好地再现我们的数据集。