Concurrent Meridional Displacements of the Eastern Centers of the Asian Subtropical Westerly Jet and South Asian High Favour East Asian Climate Anomalies

Meridional positions of the Asian Subtropical westerly jet (AWJ) in the upper troposphere and the South Asian high (SAH) in the lower stratosphere are closely linked to extreme weather and climate events in East Asia. Given the regional characteristics of these two circulation systems, this study separates each system into eastern and western centers—namely the East Asian jet (EAJ), the Central Asian jet (CAJ), the Tibetan High (TH) and the Iranian High (IH). We find that the north–south shifts of the EAJ and TH exert a more pronounced impact on precipitation and near‐surface temperature over East Asia than those of the CAJ and IH. Furthermore, the in‐phase configuration of meridional displacements of the EAJ and TH significantly modulates large‐scale three‐dimensional (3D) circulation over East Asia. In particular, when the EAJ and TH simultaneously shift northward, the Yangtze River Basin (YRB) and Tibetan Plateau (TP) region are controlled by an intense horizontal anticyclonic circulation and a common descending branch of two reversed meridional circulations, while the eastern TP is covered by the descending branch of a local zonal circulation. Consequently, there are widespread precipitation deficits and heat anomalies from the TP to the YRB. Diagnostic analysis identifies the central‐eastern equatorial Pacific SST cooling in the pre‐winter and the tropical Indian Ocean cooling in May–June as the main forcing factors of the simultaneous northward movement of the EAJ and TH during midsummer. These findings suggest that greater attention to the eastern centers of the AWJ and SAH (EAJ and TH) may benefit East Asian climate prediction.