A new NASA study shows that the warming of the tropical oceans due to climate change could lead to a substantial increase in the frequency of extreme rainstorms by the end of the century.
The research team, led by Hartmut Aumann of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, combed through 15 years of data acquired by NASA's Atmospheric Infrared Sounder instrument over the tropical oceans to determine the relationship between the average sea surface temperature and the onset of severe storms.
They found that extreme storms, which produced at least three millimeters of rain per hour over a 25 km area, formed when the sea surface temperature was higher than about 28 degrees Celsius, according to a release of JPL on Tuesday.
The team also found that 21 percent more storms form for every one degree Celsius that ocean surface temperatures rise.
Aumann said severe storms will increase in a warmer environment. Thunderstorms typically occur in the warmest season of the year.
"Our data provide the first quantitative estimate of how much they are likely to increase, at least for the tropical oceans," Aumann said.
Currently accepted climate models project that with a steady increase of carbon dioxide in the atmosphere, which is 1 percent per year, tropical ocean surface temperatures may rise by as much as 2.7 degrees Celsius by the end of the century, said the team.
If this were to happen, the frequency of extreme storms are expected to increase by as much as 60 percent by that time, according to the study.
"Our results quantify and give a more visual meaning to the consequences of the predicted warming of the oceans," Aumann said. "More storms mean more flooding, more structure damage, more crop damage and so on, unless mitigating measures are implemented."
