Fig. 5: Conceptual model of the global distribution and local structure of the TC-SGWs.

a Global distribution, local structure, and background wind of the TC-SGWs. b TC-SGW structures and/or their formation mechanism under different background winds. The shadings denote the location of the intense TC-SGWs. The red boxes in (a) denote the TC-SGW hotspots. The TC-SGW structures and/or their formation mechanism in the same green box in (b) are identical. The plus signs denote the superposition of the mechanisms on both sides, and the equal signs denote the results of the superposition. The blue and red arrows denote the tangential and radial propagation components of the TC-SGWs, respectively. The brown arrow in Fig. 5b denotes the direction of the vertical wind shear. The group of yellow arrows in Fig. 5b denotes the meridional wind shear. The length and direction of the yellow arrows denote the magnitude and direction of the wind, and the direction of the meridional wind shear can be inferred from the length and direction of the yellow arrows.