The Atlantic Multidecadal Oscillation(AMO)is the leading mode of low-frequency variability in sea surface temperatures in the Atlantic,affecting global climate.Higher-resolution models substantially improve AMO simula...The Atlantic Multidecadal Oscillation(AMO)is the leading mode of low-frequency variability in sea surface temperatures in the Atlantic,affecting global climate.Higher-resolution models substantially improve AMO simulations,closely matching observed periods and amplitudes,yet the reason for the improvement remains unclear.Here,using 4 experiments conducted within the Alfred Wegener Institute Climate Model with different atmospheric and oceanic resolutions,we found that models with a high-resolution ocean capture the positive feedback between the AMO and the Fram Strait sea ice export mediated by the Atlantic Meridional Overturning Circulation through a more realistic simulation of North Atlantic currents,extending the AMO period to 40 to 80 years.Further increasing the atmospheric resolution results in an AMO amplitude closer to observations due to stronger coupling between atmospheric blocking and Arctic sea ice.This indicates the importance of higher resolution in models for simulating the interaction between synoptic-scale atmospheric processes and long-term ocean variability,which is crucial for AMO simulations.展开更多
基金supported by the Natural Science Foundation of China under grant 42394130the Fundamental Research Funds for the Central Universities(202261002)+2 种基金supported by the Germany-Sino Joint Project(ACE,Nos.2019YFE0125000 and 01LP2004A)MHESRF Scientific Task No.FMWE-2024-0028the MIPT Development Program(Priority-2030).
文摘The Atlantic Multidecadal Oscillation(AMO)is the leading mode of low-frequency variability in sea surface temperatures in the Atlantic,affecting global climate.Higher-resolution models substantially improve AMO simulations,closely matching observed periods and amplitudes,yet the reason for the improvement remains unclear.Here,using 4 experiments conducted within the Alfred Wegener Institute Climate Model with different atmospheric and oceanic resolutions,we found that models with a high-resolution ocean capture the positive feedback between the AMO and the Fram Strait sea ice export mediated by the Atlantic Meridional Overturning Circulation through a more realistic simulation of North Atlantic currents,extending the AMO period to 40 to 80 years.Further increasing the atmospheric resolution results in an AMO amplitude closer to observations due to stronger coupling between atmospheric blocking and Arctic sea ice.This indicates the importance of higher resolution in models for simulating the interaction between synoptic-scale atmospheric processes and long-term ocean variability,which is crucial for AMO simulations.
