Waves break into the anti-tsunami barriers as a typhoon hits the area near the Iwaki town, south of the tsunami-crippled Fukushima Daiichi nuclear power plant in Fukushima prefecture.
(Photo : Reuters)
A new study released this week shows that the intensity of tropical cyclones is shifting from the tropics to the poles.
The latitude at which tropical cyclones reach their greatest intensity is shifting from the tropics toward the poles at rates of approximately 33 to 39 miles per decade, according to the study.
After researchers analyzed 30 years of global historical tropical cyclone date, their documents show a poleward migration of storm intensity in both the Northern and Southern Hemispheres.
"The absolute value of the latitudes at which these storms reach their maximum intensity seems to be increasing over time, in most places," says Kerry Emanuel, an MIT professor and co-author of the new paper, according to a university press release. "The trend is statistically significant at a pretty high level."
The study, called "The Poleward Migration of the Location of Tropical Cyclone Maximum Intensity," was co-written by lead author James P. Kossin of the National Oceanic and Atmospheric Administration's (NOAA) National Climatic Data Center, Gabriel A. Vecchi of the National Oceanic and Atmospheric Administration, and Emanuel.
Though scientists who conducted the study are still investigating the atmospheric mechanisms behind this change, the trend seems consistent with a warming climate, according to the release.
Implications are serious, since the movement of peak intensity means there is a good chance that regions further north and south of the equator, could have greater exposure to extreme weather events.
The regions have not previously had to face landfalls by violent cyclones. This could lead to "profound consequences to life and property," according to the study.
"Any related changes to positions where storms make landfall will have obvious effects on coastal residents and infrastructure," the study reads.
"It may mean the thermodynamically favorable conditions for these storms are migrating poleward," said Emanuel, the Cecil and Ida Green Professor of Earth and Planetary Sciences at MIT, according to the release.
Ocean temperatures between 82 and 86 degrees Fahrenheit are "ideal" for the genesis of tropical cyclones, according to Emanuel.
Michael Mann, a professor of meteorology and director of the Earth System Science Center at Penn State University, said cyclone migration is "a very interesting new angle on the larger issue of how climate change may be impacting tropical cyclone activity."
"The findings seem quite plausible. We know that human-caused climate change is leading to a poleward shift in certain features of the atmospheric circulation. It would be surprising if these shifts were not influencing tropical cyclones. This study shows that they are, by causing a poleward migration in the zones where atmospheric shear is either favorable or prohibitive to tropical cyclone formation," said Mann.
The study was published this week in the journal Nature.