Arctic ice forecasters help subs come up for air

As the ice melts, the race is on to exploit Arctic resources. And that means more claustrophobic submarine operations

Diminishing ice cover has increased political and economic competition for resources inside the Arctic Circle. This means more submarine operations, which are doubly claustrophobia-inducing, as a sub can only surface where the ice is comparatively thin. In an emergency, finding the nearest hole in the ice is essential, and this has spurred the development of a new type of forecast.

There are two types of hole in the ice, known as leads and polynyas. Leads are long fractures, gigantic cracks caused by ice sheets moving apart. Ultimately, they are due to wind or ocean currents pushing areas of ice in different directions. Leads are generally transient, as the seawater freezes over quickly when exposed to the cold air.