Measured and smoothed sortable silt record of sediment core GS06-144-09MC-D

Changes in the Atlantic Meridional Overturning Circulation (AMOC) have commonly been invoked to explain the low‐frequency climate changes evident over millennial‐multidecadal timescales during the Holocene period. While there is growing evidence that deep ocean circulation varied on millennial timescales, little is known about ocean variability on shorter timescales. Here we use a marine sediment core (GS06‐144‐09MC‐D) recovered from a high accumulation rate site on the Gardar Drift in the Iceland Basin (60°19′N, 23°58′W, 2081 m) to reconstruct decadal‐centennial variability in the vigor of Iceland‐Scotland Overflow Water (ISOW) with the paleocurrent proxy "sortable silt" mean grain size (ss). Our (ss) record reveals that changes in ISOW vigor have occurred on multidecadal‐centennial timescales over the past ~600 years; similar timescales as documented in Atlantic Multidecadal Variability observations and reconstructions. Our findings support a link between changes in basin‐wide climate and deep ocean circulation.

大西洋经向翻转环流（Atlantic Meridional Overturning Circulation，简称AMOC）的变化，常被用于解释全新世时期千年至数十年尺度上显著的低频气候变化。尽管已有越来越多证据表明深海环流在千年尺度上存在波动，但针对更短时间尺度上海洋变异性的研究仍较为匮乏。本研究利用采自冰岛海盆格达漂移（60°19′N，23°58′W，水深2081米）高沉积速率站位的海洋沉积岩芯（GS06-144-09MC-D），以古流代用指标“可分选沉积物平均粒径（sortable silt mean grain size，简称ss）”重建了冰岛-苏格兰溢流深水（Iceland-Scotland Overflow Water，简称ISOW）活跃度的年代至百年尺度变化。我们的ss记录显示，过去约600年间ISOW活跃度的变化呈现出数十年至百年的时间尺度特征，这与大西洋多年代际变率的观测与重建结果所揭示的时间尺度相符。本研究结果支持了盆域尺度气候变化与深海环流变化之间存在关联的结论。