This study provides valuable insight into the timing of meltwater events and associated response of AMOC during the last deglaciation. The strength of the work lies in its precisely dated chronology from a northwest Iberian stalagmite, which overcomes the chronological limitations of North Atlantic sediment records. As highlighted by Reviewer 2 “this represents a substantial advance given the impasse in what is possible based on the less precise dates of sediment cores in this interval.” The analysis of multiple proxies within the same stalagmite allows the authors to directly compare the timing of surface ocean freshening relative to regional temperature changes. Their findings reinforce the hypothesis that the AMOC response to freshwater forcing is nonlinear and may involve threshold-like transitions that are dependent on background climate states. This has broader relevance to the ongoing debate surrounding future AMOC stability.
This study provides valuable insight into the timing of meltwater events and associated response...
Stable isotope data of a precisely dated stalagmite from northwestern Iberia indicate gradual North Atlantic meltwater input during the last glacial maximum, followed by abrupt surges early in the last deglaciation. The first abrupt surge was decoupled from first cooling about 810 years later – unlike later events – which reveals that the Atlantic circulation’s sensitivity to meltwater is variable and related to the evolving background climate boundary conditions.
Stable isotope data of a precisely dated stalagmite from northwestern Iberia indicate gradual...