Recent reconstructions of bottom water δ¹³C during the last interglacial (LIG) suggest short‐lived variability in the Atlantic meridional overturning circulation (AMOC). Spontaneous (multi) centennial‐scale variability of the AMOC simulated in the Earth system model of intermediate complexity iLOVECLIM are investigated for that period. The model simulates abrupt AMOC transitions occurring at 300 years frequency and correspond to a switch of the AMOC vigor between a strong (∼17 Sv) and a weak (∼11 Sv) state. The onset of these abrupt transitions is associated with changes in orbital forcings resulting in the decline of summer insolation in the high latitudes of the North Atlantic and affecting the sea ice cover in two key deep convection regions: (1) the northern Nordic Seas (NNS) and (2) the northwest North Atlantic (NWNA). Northward inflow of Atlantic surface water increases the convection depth in (1) and strengthens the Greenland Iceland Norway (GIN) Seas overturning circulation. Subsequent ocean‐atmosphere interactions involving sea ice, ocean heat release, anomalies of evaporation‐precipitation, and wind stress over the Nordic Seas lead also to an increase in deep convection in (2), followed by increase in the AMOC strength.

中文翻译：

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最后一次冰期间大西洋经向翻转环流强度的自发（多）百年尺度变化动力学

底水最近重建δ ¹³ C ^末次间冰期（LIG）中建议在大西洋经向翻转环流（AMOC）短命的变化。在此期间，研究了在中等复杂度iLOVECLIM的地球系统模型中模拟的AMOC的自发（多）百年尺度变化。该模型模拟在300年频率和对应产生的AMOC活力的强（之间的开关突然转变AMOC 〜 17 SV）和弱（〜11 Sv）状态。这些突然转变的发生与轨道强迫的变化有关，导致北大西洋高纬度地区夏季日射量减少，并影响了两个关键的深对流区域的海冰覆盖：（1）北欧北部海域（NNS） ）和（2）西北西北大西洋（NWNA）。大西洋地表水的北向流入增加了（1）中的对流深度，并加强了格陵兰冰岛，挪威（GIN）海的翻转循环。随后的海-气相互作用涉及海冰，海洋热释放，蒸发-降水异常和北欧海域上的风应力，也导致（2）中的深度对流增加，随后AMOC强度增加。