Polynya

A polynya is like a big hole in the ice where the cold sea water is exposed to the air. Imagine you have a big sheet of ice that covers everything like a blanket. But sometimes, in certain places, there are holes in the blanket where the water is visible. That hole is called a polynya.

Now, polynyas happen when warm ocean water rises up to the surface, and then gets cooled down by the cold air. This causes the warm water to sink back down, which creates a big hole in the ice that we call a polynya.

Polynyas are important because they provide a way for the ocean to exchange heat and gases with the atmosphere. They're also important for animals like seals and penguins, who use polynyas to find food and breathe air.