Impact of the Atlantic multidecadal variability on East Asian summer climate in idealized simulations

Abstract

The impact of the Atlantic multidecadal variability (AMV) on the East Asian summer climate is analyzed using a set of idealized simulations performed by CESM1. The results show that the AMV exerts a remote impact on the East Asian summer climate via two pathways: a midlatitude Rossby wave train and equatorial Kelvin waves. Specifically, the positive phase of the AMV can enhance the land–sea pressure contrast between the Asian continent and western North Pacific Ocean through the midlatitude Rossby wave train, and induce an anomalous anticyclone in the Northwest Pacific through exciting an equatorial Kelvin wave. These anomalies in atmospheric circulation in turn enhance the East Asian summer monsoon, leading to a northern-wet–southern-dry and warm summer climate in East Asia.