Over the past fifty years, scientists have noted a change in ocean salinity. Oceans seem to be getting saltier: surface waters in tropical and subtropical Atlantic Ocean regions have become saltier while the waters in the high latitudes of the North and South Atlantic became fresher. Salty water is denser than fresh and tends to sink. If the cooler northern ocean waters become less salty, we can expect to see changes in all BUT one of these features on Earth.
