What causes a reduction in salinity in polar regions?

In polar regions, a reduction in salinity is primarily caused by ice melt. When ice, such as sea ice or glacial ice, melts, it releases freshwater into the surrounding ocean. This influx of freshwater dilutes the salinity of seawater, which is particularly significant in areas where large volumes of ice are present.

Melting ice contributes to stratification in the water column, impacting both temperature and salinity gradients. The freshwater from melting ice tends to stay on the surface, creating a low salinity layer above the denser, saltier water below. This phenomenon affects local marine ecosystems and can influence oceanic circulation patterns. The physical conditions in polar regions, including temperature and the presence of ice, make the process of ice melt a key factor in salinity reduction.