Figure 2 : Vertical wind shear (VWS) and other parameters at the typhoon genesis region.

From: Recent decrease in typhoon destructive potential and global warming implications

Figure 2

(a) Time evolution of the typhoon-season averaged VWS and zonal VWS in the typhoon genesis region in the past two decades. (b) As in a, but for the 850 hPa relative vorticity (left axis) and the genesis longitude (right axis). (c) Coherent variability between PDI, the easterly wind at 850 hPa, SHAI (subtropical height area index) at 850 hPa and the zonal VWS. Note that the three y-axes at right are reversed, so as to show the reduction in PDI (left axis) with the increase in these three suppressive parameters.