Simulated stability of the Atlantic Meridional Overturning Circulation during the Last Glacial Maximum
نویسندگان
چکیده
Abstract. The response of the Atlantic Meridional Overturning Circulation (AMOC) to freshwater perturbations critically depends on its mean state. Large swaths icebergs melting in North during last deglaciation constituted such and can, thus, provide important constraints stability AMOC. However, AMOC state Last Glacial Maximum (LGM), preceding rapid disintegration ice sheets deglaciation, as well these remain debated. Here, we investigate evolution it responds under improved LGM boundary conditions Bern3D intermediate complexity model. Particularly, consider effect an open versus a closed Bering Strait increased tidal dissipation result altered bathymetry due lower glacial sea level stand. vigorous deep conditions, consistent with previous simulations different models, reacts more strongly forcings than preindustrial conditions. This sensitivity is mostly related that cuts off escape route through Arctic into Pacific, thereby facilitating faster accumulation halting deep-water formation. Proxy reconstructions instead indicate weaker possibly shallower today, which conflict particularly strong circulation states coherently simulated ocean models for LGM. Simulations reduced formation, consequence potentially continental runoff from sheet melt imposed changes hydrological cycle, closely resemble overturning inferred proxies. These also show bistable behavior, where does not recover after hosing. no are found here either comprise extreme shoaling or concurrent shallow previously proposed based paleoceanographic data.
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ژورنال
عنوان ژورنال: Climate of The Past
سال: 2021
ISSN: ['1814-9324', '1814-9332']
DOI: https://doi.org/10.5194/cp-17-615-2021