Disappearing Arctic Sea Ice & More Powerful Storms?
New research suggests disappearing sea ice at the top of the planet is playing a "critical" role in driving colder, snowier winters here in the United States.
Retreating Arctic sea ice, according to the researchers, helps alter the atmosphere in two ways.
First, scientists found that less ice is causing a change in atmospheric circulation patterns, weakening the westerly winds that blow across the northern Pacific and Atlantic oceans. That weakened jet stream, in turn, allows more frequent surges of bitter cold Arctic air not only into the U.S., but also in Europe and east Asia.
"We have more cold air outbreaks," said Jiping Liu, a senior research scientist in the School of Earth and Atmospheric Sciences at Georgia Tech, and a co-author of the new study released today.
The second factor, Liu said, is that more water is evaporating into the air as Arctic ice at the ocean's surface melts away.
"This greatly enhances the transfer of moisture from the ocean to the atmosphere," Liu said. That humidity, he says, essentially acts as fuel to help supercharge "Snowmageddon"-type storms like the ones that paralyzed parts of the northeastern U.S. in 2010. A more recent, deadly deep freeze in Eastern Europe left 650 people dead.
"The record decline in Arctic sea ice is at least a critical contributor to recent snowy winters in northern continents," Liu said.
Liu says the new research may also help connect the dots between human-caused global warming, vanishing ice and our changing weather.
Climate researchers believe that the three-decade decline in Arctic sea ice cannot be explained by natural causes alone. The National Center for Atmospheric Research, for example, recently found that roughly half of Arctic sea ice decline from 1975 to 2005 can be blamed on the increasing amount of climate-changing greenhouse gasses, including carbon dioxide, that humans are releasing into the atmosphere.
"Is Arctic ice in a death spiral? Maybe not yet, but it's in big trouble," Mark Serreze, director of the National Snow and Ice Data Center, recently told ABC News, pointing out that the five lowest amounts of Arctic sea ice on record (since 1979) have all been recorded in the last five years.
If Arctic sea ice continues retreating as expected, the researchers said that "may load the dice" in favor of bigger, more persistent future snowstorms.
Liu stresses that many factors are at play when it comes to winter weather and insists that more research is needed to better understand the connections.
"We want to know, is this due to human induced greenhouse gasses, or natural variability? We want to figure this out," he told ABC News.
The research was conducted by scientists from Georgia Tech, the Chinese Academy of Sciences and Columbia University and appears online in the Proceedings of the National Academy of Sciences.