Brine rejection that drains from the newly formed ice is replaced by a weak flow of relatively fresh water, from the liquid region below it. The new water partially freezes within the pores of the ice, increasing the solidity of the ice. As sea ice ages and thickens, the initial salinity of the ice decreases due to the rejection of brine over time [Fig. 2]. While the sea ice ages, desalinization occurs to such a degree that some multiyear ice has a salinity of less than 1 PSU. This occurs in three different ways: Brine rejection occurs in the sea ice packs
Fresh water including ponds, lakes, swamps and mires ; lotic which are running-water systems; or groundwaters which flow in rocks and aquifers. There is, in addition, a zone which bridges between groundwater and lotic systems, which is the hyporheic zone, which underlies many larger rivers and can contain substantially more water than is seen in the open channel. It may also be in direct contact with the underlying underground water. The majority of fresh water on Earth is in ice caps. The source of almost all fresh water is precipitation from the atmosphere, in the form of mist, rain and snow. Fresh