Shifting hotspot of tropical cyclone clusters in a warming climate

Abstract

Multiple tropical cyclones can be present concurrently within one ocean basin, and these clusters can induce compound hazards within a short time window. While the western North Pacific has historically been home to most tropical cyclone clusters, how climate change might affect this is unclear. Here we use observations and high-resolution climate model simulations to develop a probabilistic model, assuming that tropical cyclones are mutually independent and occur randomly. Against this baseline, we identify outliers as clusters with dynamic interactions between tropical cyclones. We find that the recent global warming pattern induces major shifts in tropical cyclone cluster hotspots from the western North Pacific to the North Atlantic by modulating tropical cyclone frequency and synoptic-scale wave activity. Our probabilistic modelling indicates a tenfold increase in the likelihood of tropical cyclone cluster frequency in the North Atlantic, surpassing that in the western North Pacific, from 1.4 ± 0.4% to 14.3 ± 1.2% over the past 46 years.