The U.S. Atlantic Coast is becoming a hotbed for rapidly intensifying hurricanes, as climate change fuels wetter and more severe storm systems, a new study has found.
A warmer world will likely beget hurricanes that gain strength faster and exacerbate the risk of flooding along the Atlantic Coast, according to the study, published on Monday in Geophysical Research Letters.
Hurricane Ian’s recent crash-landing in Florida was among the strongest storms to arrive and is a testament to how hurricanes can suddenly turn severe, the researchers observed.
The rates at which hurricanes have strengthened near the Atlantic Coast have surged since 1979 — a trend that is poised to continue in a future marked by continued fossil fuel dependence, according to the study.
“Our findings have profound implications for coastal residents, decision- and policy-makers,” Karthik Balaguru, a climate scientist at the Department of Energy’s Pacific Northwest National Laboratory, said in a statement.
“And this isn’t specific only to the Atlantic,” Balaguru continued. “It’s happening in several prominent coastal regions across the world.”
To draw their conclusions, Balaguru and his colleagues said they probed data describing the past four decades of hurricane activity and the conditions that fueled them.
They found that a unique coastal phenomenon that cause a specific mix of environmental conditions has been driving such hurricane behavior.
And while those conditions don’t appear in the Gulf of Mexico, they could form in other regions, such as the East Asian shoreline and the northwest Arabian Sea, according to the study.
Supercharged by conditions like a warmer sea surface or increased atmospheric humidity, hurricanes like Ian can quickly intensify — crossing multiple categories in a short amount of time, the authors explained.
Because these storms build up at such high speed, they can often elude standard forecasting tools, according to the study.
While land temperatures are generally warmer than those of the sea, greenhouse gas emissions are widening that difference, the authors noted.
With drier soil, the land is unable to evaporate as much water — meaning that it can’t eliminate the extra heat trapped by greenhouse gasses as quickly as the ocean can, said atmospheric scientist Ruby Leung.
But that difference, the researchers explained, can generate stronger storms.
Over the warmer land, air pressure is lower, while over the cooler sea, air pressure is higher, the authors explained. The higher-pressure air blows inland — toward the warmer, lower pressure areas.
The Earth’s rotation then guides these winds in a cyclonic, twisting direction, pulling humid air near the surface up into the atmosphere, according to the study. Hurricanes — often dubbed “heat engines” — suck up warm, moist air and convert its energy into damaging winds.
Meanwhile, a weather phenomenon called “vertical wind shear” — which can often throw a hurricane off course — is weakening along the Atlantic coast, the researchers found.
“The nearshore environment has absolutely become more favorable for hurricanes near the Atlantic Coast,” Balaguru said.
“And that’s very consistent with the rising hurricane intensification we’ve observed in the region,” he added.