Antarctic Bottom Water!

The southern hemisphere is said to have the densest water but why is that?
It all has do to with understanding water density, as was briefly mentioned in my last post. Density of ocean water is a function of temperature and salinity. The more saline the water the more dense it is. The colder ocean water the more dense it is. Evaporation makes the water more saline and thus more dense and as a result will sink to the ocean bottom. Sea ice, which does not take up salts, makes the water more saline and thus more dense.
So what does this have to do with the southern ocean density?
Well, the freezing sea ice located in Antarctica, the coldest part of the planet, increases the salinity of the cold water forming a mass of extremely dense water. This occurs in the Weddell Sea, located off Antarctica, and forms what is known as the Antarctic Bottom water.

The final reason why the antarctic is more saline is that in the North Atlantic saline water cools and sinks to a moderate level to form the North Atlantic Deep Water, which eventually flows south and due to the fact that it isn't as dense as the Antarctic Bottom Water it actually flows to less depth relative to the situation in the southern hemisphere.
Geography rocks!
My source for this post.