The melting of the ice could set the stage for severe winters in the Northern Hemisphere's middle latitudes, with events like the "Snowmageddon" that hit Washington Feb. 3, 2010, researchers at Cornell University reported Wednesday.
"Everyone thinks of arctic climate change as this remote phenomenon that has little effect on our everyday lives," Cornell researcher Charles H. Greene said. "But what goes on in the arctic remotely forces our weather patterns here."
The melting of sea ice during summer exposes darker ocean water to incoming sunlight and increases heating of the ocean, researchers said, then the excess heat is released to the atmosphere, decreasing the temperature and atmospheric pressure gradients between the arctic and middle latitudes.
A diminished pressure gradient weakens the wind patterns that normally keep cold air masses up above the Arctic Circle and allows that cold air to invade lower latitudes, they said.
"It's a great demonstration of the complexities of our climate system and how they influence our regional weather patterns," Greene said. "What we can expect, however, is the arctic wild card stacking the deck in favor of more severe winter outbreaks in the future."