The IPSL‐CM6‐LR atmosphere‐ocean coupled model exhibits a pronounced multicentennial variability of the Atlantic meridional overturning circulation (AMOC), driven by delayed freshwater accumulation and release in the Arctic. The AMOC fluctuations are preceded by salinity‐driven density anomalies in the main deep convection sites in the Labrador and Greenland seas. During a strong AMOC, a combination of reduced sea ice volume and anomalous currents reduces the freshwater export from the Arctic and leads instead to a slow accumulation of freshwater in the central Arctic. Simultaneously, the saltier Atlantic inflow through the Barents Sea results in a positive salinity anomaly in the Eastern Arctic subsurface. When the surface Central Arctic freshwater pool finally reaches the Lincoln Sea, the oceanic currents around Greenland reorganize, leading to the export of the anomalous Arctic freshwater to the North Atlantic, enhancing the stratification in deep convection sites. The AMOC then decreases, positive salinity anomalies appear in the Central Arctic, and the variability switches to the opposite phase. These AMOC and sea ice fluctuations have broader climate impacts, with a strong AMOC leading to a mean warming of about 0.4°C north of 20°N, reaching up to 1°C in the Arctic lower troposphere during winter. In all seasons, a northward displacement of the intertropical convergence zone is also simulated.

中文翻译：

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耦合气候模型中大西洋与北冰洋之间盐度交换驱动的百年变化

IPSL-CM6-LR海洋-海洋耦合模型表现出大西洋经向翻转环流（AMOC）的显着百年变化，其受北极淡水滞后积累和释放的驱动。在AMOC波动之前，是拉布拉多和格陵兰海主要深对流部位盐度驱动的密度异常。在强AMOC期间，减少的海冰量和异常潮流共同降低了北极的淡水出口量，反而导致了北极中部的淡水积聚缓慢。同时，更咸的大西洋通过巴伦支海的流入导致东部北极地下的盐度异常为正。当北极中央表层淡水池最终到达林肯海时，格陵兰岛周围的洋流重新组织，导致北极异常淡水向北大西洋的出口，增强了深对流站点的分层。然后，AMOC降低，中部北极出现正盐度异常，并且变异性切换到相反的相位。这些AMOC和海冰的波动对气候的影响更广，AMOC的强势导致平均气温在20°N以北约0.4°C，在冬季对流层低层达到1°C。在所有季节中，也模拟了热带辐合带向北的位移。这些AMOC和海冰的波动对气候的影响更广，AMOC的强势导致平均气温在20°N以北约0.4°C，在冬季对流层低层达到1°C。在所有季节中，也模拟了热带辐合带向北的位移。这些AMOC和海冰的波动对气候的影响更广，AMOC的强势导致平均气温在20°N以北约0.4°C，在冬季对流层低层达到1°C。在所有季节中，也模拟了热带辐合带向北的位移。