Polar sea ice is ever-changing. It shrinks, expands, moves, breaks apart, reforms in response to changing seasons, and rapid climate change. It is far from a homogenous layer of frozen water on the ocean’s surface, but rather a dynamic mix of water and ice, as well as minute pockets of air and brine encased in the ice. Polar sea ice is ever-changing. It shrinks, expands, moves, breaks apart, reforms in response to changing seasons, and rapid climate change. It is far from a homogenous layer of frozen water on the ocean’s surface, but rather a dynamic mix of water and ice, as well as minute pockets of air and brine encased in the ice. Earth Sciences Environment Phys.org – latest science and technology news stories