Local and remote SST variability contribute to the westward shift of the Pacific Walker circulation during 1979–2015

Abstract During the modern satellite era since 1979, Pacific Walker circulation (PWC) experienced an intensification and a westward shift, which has broad impacts on global climate variability. While strengthening of PWC been shown to be driven by both regional sea surface temperature (SST) remote forcing from other basins, its shift is primarily attributed phase change Atlantic Multidecadal In this study, we investigate potential effect SST Indian Oceans PWC, through statistical analysis numerical experiments using atmospheric coupled models. Results show that tropical warming plays key (decisive) role in driving triggering Gill–Matsuno-type anomaly tropics. This response drives anomalous westerlies over eastern subsidence central weakens part meanwhile generating easterly wind anomalies central-western convection western intensifies PWC. direct contributes ~ 32% observed movement, while Atlantic-induced inter-basin changes contribute another 36% according model simulation results. Our results reinforce importance interactions adjusting variabilities, have implication for projecting climate.