Environment

Polar Vortex Outbreaks Linked to Vanishing Arctic Ice

Vanishing Arctic sea ice appears to have been responsible for the spells of bitterly cold wintertime conditions in the Northern Hemisphere during recent years.

Masato Mori of the University of Tokyo and colleagues found colder-than-normal winters are now twice as likely to occur across Eurasia under these conditions than before the record polar melting began.

This past September saw the sixth-lowest minimum Arctic sea ice extent ever observed.

A warming Arctic causes the polar jet stream to be weaker, allowing frigid weather systems to creep farther south.

It can also promote blocking weather patterns that cause the chill to linger for weeks.

While the study focused on a part of Eurasia that stretches from Eastern Europe to China, the past few winters have also brought frigid conditions not seen in decades to parts of Western Europe and North America.

But Adam Scaife of the U.K. Met Office says the polar blasts are likely to end once all of the ice disappears in the Arctic during autumn. Some models predict it could happen during the 2030s.

"The key thing here is that they argue that climate change wins in the long run," Scaife told New Scientist. This means that while our current winters may at times be bitterly cold, global warming will eventually catch up once the Arctic refrigerator defrosts.