Fig. 1: Features of the decay of landfalling TCs over China during 1967–2018.

Panel a shows the tracks of 141 landfalling TCs originating from the WNP over 1967–1992 (blue) and 1993–2018 (red), and a dotted box (TC pre-landfall region) bounded by 15°N, 30°N, 110°E, and 130°E. Panel b shows the spatial distribution of the 141 landfall events over China. Each circle represents the TC center 24 h after landfall over 1967–1992 (blue) or 1993–2018 (red), with its size proportional to the decay timescale τ of the event. Panel c shows the histograms and probability density functions (PDFs) of τ during the two periods of 1967–1992 (blue) and 1993–2018 (red), respectively. The difference between the two PDFs in Panel c is tested by Kolmogorov-Smirnov (K-S) test (see the p value). The error bars in histograms correspond to ±1 standard deviation in each bin, which are calculated based on bootstrap sampling method (randomly resampled with replacement in each time series). Panel d shows the time series of τ during 1967–2018. In panel d, the moving black line shows temporal change in τ; the straight black line is the corresponding linear regression line derived from ordinary least squares and the dotted black line is the 95% confidence band about the regression line. The error bars correspond to ±1 s.e.m (standard error of mean) of all events in the 5-year window centered on a given year (because the double 3-year smoothing was applied).