Recent increase in rapid intensification events of tropical cyclones along China coast

Tropical cyclone (TC) rapid intensification (RI) in the nearshore region often poses a serious threat to populated coastal regions. Although several previous studies have revealed an increased probability of RI events just before landfall in North America under global warming, it is unknown whether a similar increase has occurred along China coast. Here, we examine the long-term change of TC RI events along China coast during 1981-2020. Results show that the RI events along China coast have experienced a statistically significant increase since 1981, particularly in the latest decade. Further analysis reveals that the local sea surface temperature, maximum potential intensity, upper-level divergence, low-level vorticity, and vertical wind shear along China coast become increasingly favorable for TC RI occurrence. Among these factors, the intensified maximum potential intensity caused by the significant warming along China coast is the most important factor, most likely contributed by global warming instead of internal climate variability. This result is further confirmed by the CMIP6 model simulations.