It gets colder because the Sunlight heats the ocean and the deeper you go, the less penetrating the Sunlight is, therefore making the ocean water colder.
denser, due to the decrease in temperature causing the water molecules to contract and become more tightly packed. This increased density causes the cold water to sink to the bottom of the ocean, creating ocean currents as it displaces warmer, less dense water.
ocean water, because it is saltier.
When ocean water reaches the poles, it cools down and becomes denser, causing it to sink to deeper parts of the ocean. This cold, dense water then starts to circulate and move towards lower latitudes, influencing global ocean currents and climate patterns. Additionally, the melting of ice at the poles adds freshwater to the ocean, impacting salinity levels and ocean circulation dynamics.
Sea water is denser, not only that, different oceans have different densities.
it becomes less dense
The water of the oceans is denser because of the high level of salt it contains.
The two characteristics of water that combine to form a thermohaline current are temperature and salinity. As water becomes cold and more saline, it becomes denser and sinks to the ocean floor, driving the vertical circulation of the ocean known as the thermohaline circulation.
they sink
it becomes colder
This is an unusual question. Nothing qualitative really happens upon its increase in density and this is quite a difficult thing to do: mere fluctuations in temperature and pressure (even immense changes) can shift water's density by as much as only 3%. Water is most dense between 4 and 5 degrees celsius. There is a drop in density below this (even when supercooling the water).
When water reaches an arctic region and cools, it becomes denser and sinks due to its increased salinity and lower temperature. This process is known as thermohaline circulation, where cold water sinks and drives deep ocean currents.