Sensitivity of the Atlantic Meridional Overturning Circulation to the melting from northern glaciers in climate change experiments

A weakening of the Atlantic Meridional Overturning Circulation (AMOC) in the next century is simulated by most state‐of‐the‐art coupled models but none of them accounted for land‐ice melting. Here we evaluate the impact of this melting on future climate projection using the IPSL‐CM4 coupled ocean‐atmosphere model. For this purpose we use two different versions of the model, one with a crude land‐ice melting parameterization, and the other without. The analysis compares results of experiments where atmospheric CO2 increases by 1%/yr, performed with the two versions of this model. The AMOC is reduced by 47% when the melting of land‐ice is considered, and represents an extreme melting scenario. This reduction is of 21% without this melting. It is shown that this difference in AMOC impacts the northern hemisphere mostly through the sea‐ice cover feedback.

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