Fig. 1: Relative decreasing trend of TC rain rate.

a Spatial distribution of composite change rate of TC rainfall (mm h⁻¹ year⁻¹; shaded) and TC rain rate (mm h⁻¹; contour) at an interval of 1 mm h⁻¹, with the outmost contour being 1 mm h⁻¹. Stippling denotes an area where linear trends are statistically significant, with black and yellow dots representing 99% and 95% confidence levels, respectively. b Radial distributions of azimuthally averaged change rates of rainfall (mm h⁻¹ year⁻¹) for the background, all TCs, intense TCs (cat 1-5), and weak TCs (cat 0). c Time series and linear regression fit of area-averaged TC (black) and background (blue) rain rate (mm h⁻¹). The area averaging is taken within a radius of 500 km from TC center for rainy grids. The shading area indicates the two-sided 95% confidence bounds of the trends. d Time series and linear regression fit of relative rain rate (mm h⁻¹) for rainy grids averaged within radii of 200 km (black) and 500 km (blue). The relative rain rate is obtained as the rain rate difference between TCs and the background. The linear fitting function and correlation coefficient in (c) and (d) are also shown. The rainfall data are based on the TRMM product.