How does latitude impact the processes that control density-driven circulation? Evaluate the differences in high latitude regions of the ocean versus equatorial regions of the ocean. Why do deep waters form in high latitudes?
In the polar regions of the earth, water in the ocean becomes very cold, and forms sea ice. Consequently, the sea water that was surrounding becomes saltier, as the process of sea ice formation leaves behind salt. As the water in the sea becomes saltier, the density thereof increases, and it begins to sink. This starts the currents of the deep ocean, which drives the worldwide conveyer belt.
Deep waters form in the Antarctic and Arctic regions because dense water sinks with temperatures below 4°C from ocean surface to huge depth. Out of these two regions, a deep layer of cold water spreads over all ocean basins.