What is the main cause of ocean currents?

The primary driver of ocean currents is the interaction between wind patterns and the Earth's rotation. Wind generates surface currents in the ocean by exerting force on the water, creating movement. The Coriolis effect, which is a result of the Earth's rotation, causes these currents to be deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This combination of wind-driven forces and the Coriolis effect leads to the complex patterns of ocean currents observed around the globe.

While factors such as salinity levels and temperature differences do influence ocean currents, especially in the context of thermohaline circulation (where differences in water density drive deeper currents), they are not the primary cause of surface currents. Similarly, the shape of the coastline can affect local currents and tides, but it does not account for the global patterns established by wind and rotation. Understanding these fundamental processes is essential for grasping how ocean currents interact with the climate and ecosystems.