Question

Which sea water can have lower density? ​

Answer 1

There are two main factors that make ocean water more or less dense than about 1027 kg/m3: the temperature of the water and the salinity of the water. Ocean water gets more dense as temperature goes down. So, the colder the water, the more dense it is.

Answer 2

High salinity makes water denser. This is because there is more salt packed into the water. High temperature makes water less dense. As water gets warmer, its molecules spread out, so it becomes less dense.