Global warming intensifies pantropical coupling and its control on northern hemisphere tropical cyclones

How tropical cyclone (TC) genesis frequency will change under anthropogenic warming remains one of the most debated questions in climate science. Increasing evidence points to the importance of pantropical climate interactions in shaping extreme weather, yet their influence on TCs and their response to warming are unclear. Here, we show that the linkage between tropical Trans-Basin Variability (TBV, defined as the sea surface temperature gradient between the tropical Atlantic-Indian and Pacific Oceans) and Northern Hemisphere TC genesis has strengthened in recent decades. This intensification arises from the enhanced TBV-driven Walker circulation, which reinforces low-level convergence and ascent conducive to TC formation. Analysis of 29 state-of-the-art climate models indicates that this TBV-TC connection will continue to strengthen under future warming. Our findings suggest that global warming amplifies pantropical coupling and its control on Northern Hemisphere TCs, offering a new pathway through which climate change can modulate TC activity.