Fig. 6: Schematic representation illustrating the relationship between the movement of the Asia-Pacific jet core and the increase in upper-level geopotential height.

(1) Latitudinal motion of the Asia-Pacific jet core according to the CESM1 experiment: XAER(red), XGHG(blue), and CESM1-LE (yellow; All forcing). (2) Meridional gravity wave drag (VGWD) caused by southerly winds introduced by the latitudinal movement of the Asia-Pacific jet. (3) Mountain lifting as southerly winds reach the Alaskan Range. (4) This results in a strengthening of the upper-tropospheric ridge.