Sea ice also affects the movement of ocean waters. The ocean is salty and when sea ice forms, much of the salt is pushed into the ocean water below the ice, although some salt may become trapped in small pockets between ice crystals. Water below sea ice has a higher concentration of salt and is denser than the surrounding ocean water, so it sinks and moves from the surface. In this way, sea ice contributes to the circulation of the global ocean conveyor belt. Cold, dense polar water descends from the surface and circulates along the ocean bottom toward the equator, while warm water from mid-depth to the surface travels from the equator toward the poles. here were you can find it https://oceanservice.noaa.gov/facts/sea-ice-climate.html
