Fig. 3: Concurrences of TC rainfall and drought termination events.

a trend of the number of named TCs (TC, red lines) and terminate drought (DT, blue lines) events derived from SPI-12 using CMORPH precipitation dataset for the area affected by TC as shown in Supplementary Fig. 5. The top number inserted in the plots is the slope of Poisson regression (+0.17% and −1.52% per year), and the number in parentheses (0.57 and 0.00) is the significance level of the Poisson regression. b the same as a, but for named TCs that caused DT events (DT-TC, red lines) and DT events caused by high TC rainfall (TC-DT, blue lines). c global distribution of precursor coincidence rate of high TC rainfall events to drought termination events. The pie chart shows the degree of TC impact on the land part of each hotspot area. High TC rainfall events are defined as the combined TC rainfall of two neighboring months exceeds 50% of the total precipitation for those 2 months. A climatological transition at the end of a drought event from the first month of SPI less than −1.0 to the following month of SPI larger than −0.5 is regarded as a DT event. The concurrence of high TC rainfall events and drought termination events is defined as a tropical cyclone-related drought termination (TC-DT) event. Slash lines indicate regions of statistically significant precursor coincidence rate. The red boxes show the four hotspots of high concurrence probabilities of high TC rainfall events to drought termination events, including the east and west of North and Central America (d), the Arabian Peninsula and South Asia (e), the Southeast and East Asia (f), and the northwest of Australia (g). h spatial distribution of the peak month of high TC rainfall, and i the spatial distribution of peak month of drought events from 1999 to 2021, respectively. Only regions impacted by TCs are shown in the maps and quantitatively analyzed for drought termination.