Featured Research

from universities, journals, and other organizations

Dangerous storms: Hurricanes peaking further north, typhoons further south, than in past

Date:
May 14, 2014
Source:
Massachusetts Institute of Technology
Summary:
Powerful, destructive tropical cyclones are now reaching their peak intensity farther from the equator and closer to the poles, according to a new study. The results of the study show that over the last 30 years, tropical cyclones -- also known as hurricanes or typhoons -- are moving poleward at a rate of about 33 miles per decade in the Northern Hemisphere and 38 miles per decade in the Southern Hemisphere.

A NASA computer model simulates Hurricane Sandy's progression. On Oct. 29, 2012, a day before landfall, Sandy intensified into a Category 2 superstorm nearly 1,000 miles wide.
Credit: Courtesy of NASA/Goddard Space Flight Center/William Putman

Powerful, destructive tropical cyclones are now reaching their peak intensity farther from the equator and closer to the poles, according to a new study co-authored by an MIT scientist.

The results of the study, published today in the journal Nature, show that over the last 30 years, tropical cyclones -- also known as hurricanes or typhoons -- are moving poleward at a rate of about 33 miles per decade in the Northern Hemisphere and 38 miles per decade in the Southern Hemisphere.

"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. "The trend is statistically significant at a pretty high level."

And while the scientists who conducted the study are still investigating the atmospheric mechanisms behind this change, the trend seems consistent with a warming climate.

"It may mean the thermodynamically favorable conditions for these storms are migrating poleward," adds Emanuel, the Cecil and Ida Green Professor of Earth and Planetary Sciences at MIT.

The implications are serious, since the movement of peak intensity means regions further north and south of the equator, which have not previously had to face many landfalls by violent cyclones, may now have greater exposure to these extreme weather events. That, in turn, could lead to "potentially profound consequences to life and property," the paper states. "Any related changes to positions where storms make landfall will have obvious effects on coastal residents and infrastructure."

Moving with the trade winds?

The paper, "The Poleward Migration of the Location of Tropical Cyclone Maximum Intensity," was co-written by Emanuel, James P. Kossin of the University of Wisconsin, and Gabriel A. Vecchi of the National Oceanic and Atmospheric Administration (NOAA).

To conduct the study, the scientists used international data from 1982 to 2012, collected by NOAA's National Climactic Data Center. They used the location of peak intensity of cyclones as a benchmark because it is a more consistent metric than statistics such as storm duration: The duration can be harder to estimate because of difficulties in establishing precisely when a storm should first be considered a tropical cyclone.

While there are regional differences in the poleward movement of cyclones, the fact that every ocean basin other than the northern Indian Ocean has experienced this change leads the researchers to suggest, in the paper, that this "migration away from the tropics is a global phenomenon."

However, Emanuel notes, the global mechanisms underlying the trend are a matter for further research.

"We think, but have not yet been able to establish, that this is connected to independently observed poleward expansion of the Hadley circulation," Emanuel says, referring to a large-scale pattern of global winds, which in recent years has also moved further poleward. The paper notes the potential impact of vertical wind shear, which inhibits cyclone formation; data suggests a decrease in wind shear in the tropics and an increase at higher latitudes.

Emanuel notes that researchers in the field are continuing to examine the links between storm migration and global warming. Over the past three decades, the incidence of cyclones in the tropics has actually diminished -- because while tropical cyclones may become more intense in a warmer climate, it is actually more difficult to generate them.

Ocean temperatures between 82 and 86 degrees Fahrenheit seem to be "ideal for the genesis of tropical cyclones," Emanuel says, "and as that belt migrates poleward, which surely it must as the whole ocean warms, the tropical cyclone genesis regions might just move with it. But we have more work to do to nail it down."


Story Source:

The above story is based on materials provided by Massachusetts Institute of Technology. The original article was written by Peter Dizikes. Note: Materials may be edited for content and length.


Cite This Page:

Massachusetts Institute of Technology. "Dangerous storms: Hurricanes peaking further north, typhoons further south, than in past." ScienceDaily. ScienceDaily, 14 May 2014. <www.sciencedaily.com/releases/2014/05/140514133432.htm>.
Massachusetts Institute of Technology. (2014, May 14). Dangerous storms: Hurricanes peaking further north, typhoons further south, than in past. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2014/05/140514133432.htm
Massachusetts Institute of Technology. "Dangerous storms: Hurricanes peaking further north, typhoons further south, than in past." ScienceDaily. www.sciencedaily.com/releases/2014/05/140514133432.htm (accessed October 1, 2014).

Share This



More Earth & Climate News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Newsy (Sep. 30, 2014) — A new study published by the World Wide Fund for Nature found that more than half of the world's wildlife population has declined since 1970. Video provided by Newsy
Powered by NewsLook.com
Seismic Activity Halts Recovery at Japan Volcano

Seismic Activity Halts Recovery at Japan Volcano

AP (Sep. 30, 2014) — Rescuers were forced to suspend plans to recover at least two dozen bodies from near the summit of Mount Ontake in central Japan on Tuesday after increased seismic activity raised concern about the possibility of another eruption. (Sept. 30) Video provided by AP
Powered by NewsLook.com
Dolphins Might Use Earth's Magnetic Field As A GPS

Dolphins Might Use Earth's Magnetic Field As A GPS

Newsy (Sep. 30, 2014) — A study released Monday suggests dolphins might be able to sense the Earth's magnetic field and possibly use it as a means of navigation. Video provided by Newsy
Powered by NewsLook.com
How To Battle Stink Bug Season

How To Battle Stink Bug Season

Newsy (Sep. 30, 2014) — Homeowners in 33 states grapple with stink bugs moving indoors at this time of year. Here are a few tips to avoid stink bug infestations. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins