The cold snap has nearly frozen over the American side of Niagra falls. Photo: Geoff Robins / AFP via Getty Images
This weekend could be the coldest on record for several areas across the Northeast, brought on by what several scientists say is a weakening polar vortex. Meanwhile, the rest of the world is currently experiencing warmer-than-average temperatures, including both the North and South poles. The connection between these seemingly contradictory weather patterns may be climate change.
The bottom line: The consensus among researchers is that the Arctic is warming faster than any other region in the world. The resulting loss of sea ice in the area could be weakening the polar vortex, allowing cold air from the North Pole to be misplaced over lower latitudes, like North America, and thus creating these cold snaps. But the extent of that link is debated.
The breakdown: Super cold air is usually trapped in the Arctic by the polar vortex, a massive circular weather pattern around the North Pole. Judah Cohen, Director of Seasonal Forecasting at Atmospheric and Environmental Research, described the polar vortex as acting like a dam that locks the frigid air up north. But Cohen says Arctic warming weakens the polar vortex — and bursts that dam. "Warm air then rushes up to the pole, and the cold previously located over the Arctic escapes ... to lower latitudes where it's not normally residing."
The debate: While there is increasing evidence Arctic warming and colder winters are related, "less consensus has been achieved so far about the mechanisms underlying the linkages between Arctic climate changes and atmospheric circulation changes over North America," said Doerthe Handorf, a climate researcher with the Alfred Wegener Institute.
Weather is a complex system driven by a lot of other factors — including ocean currents and atmospheric processes. Improved models and data have only recently uncovered direct links between some major weather anomalies and climate change. But the science is still new. "Existing knowledge gaps and controversy ... among the scientific community" have to be settled to understand the complex relationship between the polar vortex and climate change.
Why it matters: "These extreme [weather] events and their links to conspicuous climate change (such as the Arctic meltdown) are helping the public to understand that climate change is not a problem for the future. It's happening right now to all of us," said Jennifer Francis, Research Professor at Rutgers University's Institute of Marine and Coastal Sciences.