What would lower ocean water density?

Evaporation of water at lower latitudes will increase the salinity, and increase the density of the water. Because of the molecular structure of water, water is the densest at 4˚C, so lowering the temperature of water, such as near the poles would also increase the density of ocean water. read more

The density of seawater plays a vital role in causing ocean currents and circulating heat because of the fact that dense water sinks below less dense. Salinity, temperature and depth all affect the density of seawater. Density is a measure of how tightly a certain amount of matter is packed into a given volume. read more

Density of ocean water at the sea surface is about 1027 kg/m 3. There are two main factors that make ocean water more or less dense than about 1027 kg/m 3: the temperature of the water and the salinity of the water. read more