Tipping mechanisms in a conceptual model of the Atlantic Meridional Overturning Circulation

The Atlantic Meridional Overturning Circulation (AMOC) forms an essential component of the global ocean circulation. Paleoclimate records indicate the AMOC’s capability to tip between different states that resulted in large global climate impacts. Using an AMOC box model, re-calibrated against a global circulation model, HadGEM3, we present a new bifurcation analysis and showcase mechanisms that may lead the AMOC to tip from its current ‘on’ state to a collapsed ‘off’ state under climate change. We find that bifurcation- and noise-induced tipping remain viable tipping mechanisms as in previous calibrations, while rate-induced tipping only occurs for specific parameter configurations of this model.