AMO footprint of the recent near-surface wind speed change over China

Abstract

The continuous reduction in near-surface wind speed (NSWS) before 2010, commonly referred to as ‘stilling’, has been widely observed across land areas in the Northern Hemisphere (NH), though its underlying mechanisms remain unclear. In this study, we presented robust evidence linking the Atlantic multidecadal oscillation (AMO) to the stilling over China between 1970 and 2010. Positive AMO phases trigger warming across the NH high-latitudes, weakening the large-scale meridional temperature gradient, and eventually leading to the reduction in NSWS in mid-latitude regions. We confirmed this effect through the Coupled Model Intercomparison Project phase 6 Decadal Climate Prediction Project and historical simulations, which consistently reproduce the AMO’s impact on NSWS change over China. Additionally, large-ensemble simulations suggest that excluding the contribution of AMO reduces the uncertainty in NSWS trends from 1976 to 2005 by 19%. Our findings underscore the critical footprint of natural internal variability, particularly the AMO, in modulating regional NSWS and highlights its important role in the broader climate system.

Keywords

• near-surface wind speed
• decadal variation
• atlantic multidecadal oscillation
• China