Unravelling the mystery: The key role of tides in strengthening AMOC during the Bølling-Allerød epoch

The Bølling-Allerød (BA) period, characterized by rapid climate warming, provides a unique opportunity to study the dynamics of the Atlantic Meridional Overturning Circulation (AMOC). Despite expectations that the AMOC would weaken due to substantial meltwater input from Northern Hemisphere ice sheets, proxy data evidence suggests it unexpectedly strengthened during this transition. In this study, we examine the previously unconsidered role of tides during the BA period through a series of ocean circulation model simulations. Our findings indicate that enhanced tidal mixing during the BA significantly contributed to the rapid amplification of the AMOC, also increasing its resilience to freshwater inputs from deglaciation. This research provides a novel explanation for the AMOC's rapid amplification and resilience during the BA period, emphasizing the critical role of tides in enhancing our understanding of abrupt climate transitions and future climate change.