It's as if the world has been turned upside-down, or at least its weather. You can blame the increasingly familiar polar vortex, which has brought a taste of the Arctic to places where winter often ...

Roughly twenty miles above Earth's surface, in a largely invisible layer of the atmosphere called the stratosphere, some of the most dramatic temperature changes on our planet unfold. Major sudden ...

The polar vortex that has dealt the most brutal winter to much of the US in recent years is about to be broken down – but not ...