Arctic ice melt sets stage for severe winters, scientists say

Media Contact

John Carberry
Severe winter weather outbreaks are more likely due in part to the seemingly far-off problem of melting sea ice in the Arctic.

The dramatic melt-off of Arctic sea ice due to climate change is hitting closer to home than millions of Americans might think. That's because melting Arctic sea ice can trigger a domino effect leading to increased odds of severe winter weather outbreaks in the Northern Hemisphere's middle latitudes -- think the "Snowmageddon" storm that hamstrung Washington, D.C., during February 2010.



A warmer Earth increases the melting of sea ice during summer, exposing more dark ocean water to incoming sunlight. This causes increased absorption of solar radiation and excess summertime heating of the ocean -- further accelerating the ice melt. The excess heat is released to the atmosphere, especially during the autumn, decreasing the temperature and atmospheric pressure gradients between the Arctic and middle latitudes.

polar ice diagram


The recent observations present a new twist to the Arctic Oscillation (AO) -- a natural pattern of climate variability in the Northern Hemisphere. Before humans began warming the planet, the Arctic's climate system naturally oscillated between conditions favorable and those unfavorable for invasions of cold Arctic air.

Greene says, "What's happening now is that we are changing the climate system, especially in the Arctic, and that's increasing the odds for the negative AO conditions that favor cold air invasions and severe winter weather outbreaks.


But wait -- Greene and Monger's paper is being published just after one of the warmest winters in the eastern U.S. on record. How does that relate?


"It turns out that while the eastern U.S. missed out on the cold and snow this winter, and experienced record-breaking warmth during March, many other parts of the Northern Hemisphere were not so fortunate," Greene said. Europe and Alaska experienced record-breaking winter storms, and the global average temperature during March 2012 was cooler than any other March since 1999.



Story Contacts