Marine heat waves — large, persistent patches of unusually hot ocean water — are dramatically amplifying the destructive power of hurricanes and tropical cyclones worldwide, according to a study published Friday in the journal Science Advances. Researchers analyzed 1,600 tropical cyclones that made landfall since 1981 and found that storms passing over these superheated zones were far more likely to intensify rapidly, resulting in 60% more disasters causing at least $1 billion in damage.
"These marine heat waves affect more than half of landfalling tropical cyclones," said study co-author Gregory Foltz, an oceanographer at the National Oceanic and Atmospheric Administration. "They're happening closer to land and more frequently, so I think people need to pay attention." Warm ocean water has long been understood as fuel for hurricanes, but the study quantifies for the first time how the growing prevalence of marine heat waves — defined as sustained areas of water in the top 10% of historical temperatures — is translating into escalating economic destruction.
The researchers pointed to several recent storms as cautionary examples. Hurricanes Helene and Milton struck Florida's west coast within weeks of each other in 2023, both rapidly intensifying over abnormally warm Gulf waters. Hurricane Otis provided an even more dramatic case, exploding from a tropical storm to a Category 5 hurricane in a single day before slamming into Acapulco, Mexico, causing $16 billion in damage and 52 deaths. Critically, the study's authors said the increased damage was not simply a function of more development along coastlines. Storms that crossed hot water were compared against those hitting similarly urbanized areas without marine heat wave exposure, isolating the ocean's role. As climate change continues to heat the world's oceans, the findings suggest that forecasters and emergency planners will need to pay closer attention to marine heat waves as a key predictor of catastrophic storm impacts.