Fig. 8

(a–d) 700 hPa lower-level jet (unit: m s⁻¹), wind fields (wind barbs), and the black solid line represents the area with divergence less than -2 × 10⁻⁵ s⁻¹, and the topography (shading). The red solid line represents the boundary of the NX, and the blue solid lines represent lakes.