US braced for -50C temperatures as polar vortex bites
Weakened 'polar vortex' blamed for N. American chill
In pictures: Polar vortex strikes North America - BBC News
Eight die as polar vortex brings life-threatening temperatures to US Midwest | US News | Sky News
What 5 Million Data Points Tell Us About the Polar Vortex's Impact on Energy Use | Greentech Media
What Does 'America First' Look Like in the Arctic? | RAND
Polar Bear Facts: Animals of North America - WorldAtlas
The U.S. is about to get a potent polar vortex blast - Science
Environment America takes legal action to protect polar bears in Alaska | Environment America
In the Arctic National Wildlife Refuge, polar bears and oil drilling do not mix | Environment America
As Polar Vortex Stirs, Deep Freeze Threatens U.S. and Europe - Bloomberg
What is the polar vortex – and how is it linked to climate change? | US weather | The Guardian
America and Russia work together during challenging times | WWF Arctic
In pictures: Polar vortex strikes North America - BBC News
Polar Vortex Building in North America
Polar vortex whips millions of Americans with strong winds, freezing temperatures and even snow - CNN
Polar Bear Watching Trips: Tailor-Made Ideas and Group Tours | Wildlife Worldwide
Weakening polar vortex may yield longer, harsher winters in North America | AccuWeather
Polar vortex coming in November: Arctic blast to central, eastern U.S.
Map of where bears live in North America
We're not the only ones... Arctic storm with POLAR VORTEX cripples America | Nature | News | Express.co.uk
The polar vortex is coming—and raising the odds for intense winter weather
Polar vortex: cold that has killed dozens to give way to 'spring-like' weather | US weather | The Guardian
President Trump's New Polar Strategy Is the First Step to Defending the Arctic | Military.com
Polar Vortex Building in North America
See all 70 polar bears in North American Zoos (interactive) - oregonlive.com
