Weakening of the Silk Road Pattern in August after the Mid-1990s

Abstract

Abstract This study identified that the Silk Road pattern (SRP), which is a teleconnection pattern along the Asian upper-tropospheric westerly jet, becomes significantly weakened in August after the mid-1990s. The SRP in August dominates the upper-tropospheric meridional wind variability over the Eurasian continent before the mid-1990s but does not afterward. Further results suggested that the summer North Atlantic Oscillation (SNAO) and the South Asian rainfall play a role in inducing this decadal weakening of SRP. Before the mid-1990s, the SNAO is stronger and its southern pole is located over northwestern Europe but is weakened and its southern pole shifts southwestward afterward, resulting in the decadal weakening of its contribution to the SRP. In addition, the relationship between the SRP and South Asian rainfall is substantially weakened after the mid-1990s, which also contributes to the weakening of SRP.