The Labrador Current (LC) provides freshwater from the Arctic to the North Atlantic, modulating the Atlantic Meridional Overturning Circulation (AMOC), and therefore affecting the broader North Atlantic climate. The Holocene alongflow variability of the LC vigor, and the associated forcing mechanisms, are poorly understood due to the limited data near the southern limit of the LC. Here we present a new 9.4 ka record of distal LC vigor over the Scotian Shelf using the sortable-silt proxy, which allows for the first time an assessment of the alongflow changes in Holocene LC vigor and hence its forcing mechanisms. LC speed on the Scotian Shelf decreased slightly from 9.4 to 8.0 ka, during which the 8.1 ka meltwater event had a strong influence. The LC progressively intensified from 8.0 to 5.0 ka, weakened between 5.0 and 1.8 ka and gradually intensified from 1.8 to 0.5 ka. Our synthesis reveals that the Holocene flow history of the LC appears geographically variable due to the interaction of the inner and outer LC. The mean size of the sortable silt data on the Scotian Shelf involve inner or outer LC signals in different periods of the Holocene. The LC vigor on the Scotian Shelf between 9.4–8.0 ka and 1.8–0.5 ka represent the outer LC, which is consistent with the stronger West Greenland Current and increased influx of Atlantic-sourced water to the outer LC. We find a broad agreement between inner LC vigor and AMOC-related sea surface temperature (SST) of the subpolar North Atlantic and the North Atlantic Oscillation (NAO), which suggests that a strong (weak) inner LC is generally associated with regional warm (cold) climate and negative (positive) NAO. The outer LC vigor is dominated by the NAO during the Holocene and partly controlled by freshwater supply between 10.0 and 5.0 ka. We also demonstrate the negative/positive link between the inner/outer LC vigor and the NAO on a millennium time scale. This study improves our understanding of LC variability and sensitivity to anthropogenic warming, and suggest that inner (outer) LC vigor may experience not only a decreasing (increasing) trend in a future warmer climate, with additional effects resulting from enhanced melting of the Greenland ice sheet.2

拉布拉多洋流 (LC) 从北极向北大西洋提供淡水，调节大西洋经向翻转环流 (AMOC)，从而影响更广泛的北大西洋气候。由于 LC 南部极限附近的数据有限，对 LC 活力的全新世沿流变异性以及相关的强迫机制知之甚少。在这里，我们使用可分类的淤泥代理展示了苏格兰大陆架上远端 LC 活力的新 9.4 ka 记录，这首次允许评估全新世 LC 活力的沿流变化及其强迫机制。Scotian Shelf 的 LC 速度从 9.4 ka 略微下降到 8.0 ka，在此期间 8.1 ka 融水事件产生了强烈影响。LC 从 8.0 到 5.0 ka 逐渐增强，在 5.0 和 1 之间减弱。8 ka 并从 1.8 ka 逐渐增强到 0.5 ka。我们的综合表明，由于内部和外部 LC 的相互作用，LC 的全新世流动历史在地理上是可变的。Scotian Shelf 可分选淤泥数据的平均大小涉及全新世不同时期的内部或外部 LC 信号。苏格兰大陆架上 9.4-8.0 ka 和 1.8-0.5 ka 之间的 LC 活力代表外部 LC，这与更强的西格陵兰洋流和大西洋源水流入外部 LC 的增加一致。我们发现内部 LC 活力与次极地北大西洋和北大西洋涛动 (NAO) 的内部 LC 活力与 AMOC 相关海面温度 (SST) 之间存在广泛一致，这表明强（弱）内部 LC 通常与区域温暖有关。寒冷）气候和消极（积极）NAO。全新世期间，外部 LC 活力由 NAO 主导，部分受 10.0 至 5.0 ka 之间的淡水供应控制。我们还展示了千年时间尺度上内部/外部 LC 活力与 NAO 之间的负/正联系。这项研究提高了我们对 LC 变异性和对人为变暖敏感性的理解，并表明内部（外部）LC 活力可能不仅会在未来变暖的气候中经历减少（增加）趋势，而且还会因格陵兰冰的融化加剧而产生额外影响表.2