Worsening ocean heat waves are ‘supercharging’ hurricane damage, study finds
WASHINGTON (AP) — Marine heat waves are supercharging damage caused by hurricanes and tropical cyclones across the globe, a new study found.
Researchers looked at 1,600 tropical cyclones — the broader category of storms that includes hurricanes — that made landfall since 1981 and found those that went over the extra-hot water were more likely to intensify rapidly, a problem that’s becoming more frequent. This resulted in 60% more disasters that caused at least $1 billion in damage — adjusted for inflation — when they hit land, according to a study in Friday’s journal Science Advances.
A better understanding of how marine heat waves amplify hurricanes could help forecasters, emergency officials and long-term planners prepare for future storms.
The study defined marine heat waves as long-lasting, large areas of water in the top 10% of historical heat. They are becoming more of a danger with climate change and ever hotter oceans, study authors said. Warm water is fuel for hurricanes.
“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 and know that these are more likely to result in extreme damages when they make landfall.”
It’s important for meteorologists forecasting the storm track to see if these hurricanes go over a marine heat wave because it is more likely to intensify rapidly which “can potentially have a bigger impact on landfall,” Foltz said.
Just look at damaging hurricanes that smacked the United States in 2023, said study co-author Hamed Moftakhari, a coastal engineering professor who studies compound hazards at the University of Alabama.
“The story of Helene and Milton is that if you’ve got a warmer ocean, you’ve got the fuel to supercharge tropical cyclones even in a cascade. So within a few weeks you could get two rapidly intensified hurricanes making landfall in the west coast of Florida,” Moftakhari said. “This is shocking but should also be alarming for people.”
The study also points to October 2023’s Hurricane Otis, which rapidly intensified from a tropical storm to a top level Category 5 hurricane in one day, then caused about $16 billion in damage and 52 deaths when it made landfall near Acapulco, Mexico, with 165 mph (265 kph) winds.
Researchers said the higher damage, compared with storms that didn’t cross marine heat waves, wasn’t driven by increased coastal development. Storms that crossed hot water and hit developed coasts were contrasted with other storms that hit similarly urbanized areas but without crossing hot water, said study lead author Soheil Radfar, a scientist who does hurricane hazard modeling at Princeton University.
Science has long known that warm water fuels and often strengthens tropical cyclones, providing more of a link on causation.
That means the future looks more dangerous, Radfar said.
“All these pieces of the puzzle are going to be really challenging for the coastal environment in the next four decades when you have more rapid intensification, more marine heat waves,” Radfar said. This “is going to be really costly and frightening for the coastline environment, and it’s going to cause more billion-dollar disasters in the future.”
Moftakhari said “from a coastal engineering and risk management perspective, this has important implications for how governments plan, design, and respond to these hazards.”
Evacuation planning must account for storms that cross ocean hot spots being more likely to intensify rapidly and pose greater threats, according to Moftakhari. Earlier warnings and triggers on when people leave may be needed when there are marine heat waves. Designs for flood protection, drainage system, sea walls all have to be updated to the new worsening storm reality, he said.
Outside scientists said the study fits with the known physics of hurricanes and climate change, while putting a more specific number on the likelihood for mega-damage when marine heat waves are present.
“Climate change is causing stronger and longer-duration marine heat waves. Tropical cyclones draw their energy and produce heavy rain via evaporation from warm ocean waters,” said University at Albany atmospheric sciences professor Brian Tang, who wasn’t part of the study. “It’s reasonable that marine heat waves are turbocharging hurricanes, provided other environmental conditions are favorable for hurricanes to intensify. In effect, the dice is being loaded.”
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