What primarily drives thermohaline circulation in oceans?

Thermohaline circulation is primarily driven by density differences in ocean water, which arise from variations in temperature and salinity. This process is crucial for distributing heat and nutrients across the ocean and influences global climate patterns. When water becomes colder or saltier, it increases in density, causing it to sink. Conversely, warmer or less salty water is less dense and tends to rise. This continuous movement creates a global conveyor belt of water flow, connecting different regions of the world's oceans.

While marine life contributes to certain local aspects of ocean dynamics, it is not the main driver of thermohaline circulation. Temperature uniformity does not hold in practice as water temperature varies in different regions, leading to the creation of density gradients. Although wave action and surface winds affect surface currents, they do not significantly influence the deep ocean currents associated with thermohaline circulation. Thus, density differences are the key factor in understanding this complex system.