Abstract Proxy records indicate a robust Atlantic Meridional Overturning Circulation (AMOC) during the Bølling–Allerød (BA) interstadial, despite substantial meltwater discharge. Using ocean circulation simulations, we demonstrate that enhanced tidal mixing, sustained by lower‐than‐modern sea levels, significantly strengthens the BA AMOC and increases its freshwater collapse threshold from 0.04 to 0.12 Sv. We find that the weak stratification characteristic of the BA period triggers a positive feedback that amplifies both tidal mixing and overturning. These results identify tidal mixing as a critical, yet previously underexplored, control on AMOC tipping behavior during abrupt climate transitions. Characterizing the AMOC's response to such forcings provides vital insights into the mechanisms governing AMOC stability and variability under future climate change scenarios.
Chen et al. (Tue,) studied this question.