Atlantic Ocean Leakage/Rings, which brings salty Indian Ocean waters into the South Atlantic, and the "Atmospheric Bridge", which evaporates subtropical Atlantic waters and exports it to the Pacific. The Atlantic Ocean consists of four major, upper water masses with distinct temperature and salinity. The Atlantic Subarctic Upper Water in the northern-most North Atlantic is the source for Subarctic Intermediate Water and North Atlantic Intermediate Water. North Atlantic Central Water can be divided into the Eastern and Western North Atlantic central Water since the western part is strongly affected by the Gulf Stream and therefore the upper layer is closer to underlying fresher
North Water Polynya Smith Sound, Lady Ann Strait, and Lancaster Sound. The West Greenland Current follows that country's coastline and moves warm and salty Atlantic water north, reaching all the way to the North Water Polynya. An upwelling of warmer water in this polynya helps keep it partially ice-free throughout the year, even when the ocean directly north and south is frozen. Another arm of the West Greenland Current reaches into Lancaster Sound, delivering Atlantic waters into the Arctic Ocean and contributing to that area's rich ecology. The lands adjacent to the North Water have been recognized internationally for their importance. In 1974