, and the slope of the fitted line is reported in the bottom right corner. The binned averages of the current speeds are calculated from the ageostrophic current speeds in every 0.1 m sbin, and the corresponding observed wind speeds are taken to calculate the binned averages of the observed wind speeds., Comparison of the binned averages of the theoretical wind speeds estimated from the ageostrophic currents and observed wind speeds .
Extended Data Fig. 2 Winds of weak TCs derived from drifter current measurements based on typhoon wind field model of Batts., The difference of spatial averages between the theoretical wind fields and composite wind fields for each five-consecutive-year period from 1991 to 2020. The length of the error bar for each period is twice the standard deviation divided by the square root of the effective number of observations during that period .