During the summer, NASA scientist Tim Hall analyzed the data of more than 70 years of hurricane activity in the Atlantic Ocean. He found that the propensity of a storm to hover or “stall” over land for a prolonged period of time has increased.
In fact, Hall watched in awe as Hurricane Dorian, a category 5 storm, lay stationary just above the islands of Great Abaco and the Bahamas. Hall said, “[Watching it] just spinning there, spinning there, spinning there, over the same spot. You can’t help but be awestruck to the point of speechlessness.”
Warmer Climate to Blame for Stronger Storms
Atmospheric Scientist at Woods Hole Research Center, Jennifer Francis argues that the speed at which storms are intensifying is directly related to the warmer temperatures in the Atlantic. According to the National Oceanic and Atmospheric Administration, “More than 90% of the warming that has happened on Earth over the past 50 years has occurred in the ocean.”
Since storms derive most of their energy from the heat in the ocean, an increase in warming will inevitably lead to an increase in storm intensity. “Rapid intensification” is the term used to describe how quickly a category 1 tropical storm can become a category 4 or 5 hurricane in a short period of time. In fact, Hurricane Harvey, which devasted Houston, Texas went from a category 1 to a fierce category 4 storm in 24 hours.
Hurricane Dorian And Climate Change
Hurricane Dorian either matched or exceeded previous records in regard to intensity and sluggish pace as it slid over the Bahamas. It only took 9 hours for its winds to increase from 150 mph to 180 mph. Once it reached land, its wind speeds peaked at 185 mph making it one of the strongest hurricanes in the Atlantic.
Scientist Jennifer Francis said that the 1° C warmer temperature of the water in which Hurricane Dorian formed “translates to a whole bunch of energy.”
Since warm air contains more moisture, the warmer temperatures due to climate change produce wetter storms which contribute to the growth of a hurricane. “When that water vapor condenses into cloud droplets, it releases a lot of heat into the atmosphere and that’s what a hurricane feeds off of,” Francis said.
The Future of Hurricane Activity
According to storm models, both category 4 and 5 hurricanes that form over the North Atlantic Ocean may occur twice as often over the next 100 years. A 2018 paper written by Atmospheric Research Scientist, Jim Kossin, found that tropical storms have slowed down tremendously across the world.
This “stalling” mechanism allows tropical storms to build up energy before unleashing devastating amounts of rain and heavy winds in a centralized location. Even if storms do begin to occur less frequently, their intensity is only going to increase. Hurricane Dorian is proof.