sea ice In polar regions the surface of the sea freezes, due to the low air and water temperatures: the product is known as ‘sea ice’. It exists year-round in the central Arctic and in some Antarctic bays, extending in winter across the entire Arctic and far out to sea around Antarctica. As ice crystals form from sea water, so salt is excluded and eventually returned to the sea. Sea ice therefore contains no salt, except where pockets of sea water become trapped in the ice.

sea ice Ice that floats on the surface of the sea in polar regions. It exists throughout the year in the central Arctic and in some Antarctic bays, extending in winter across the entire Arctic and far out to sea around Antarctica. As ice crystals form from sea water, so salt is excluded and eventually returned to the sea. Sea ice therefore contains no salt, except where pockets of sea water become trapped in the ice.