Which one among the following is not a cause of generation of ocean currents ?

Ocean currents are generated and influenced by several primary and secondary forces. Planetary winds are a dominant factor, driving surface currents through frictional drag [2]. Variations in ocean water temperature and salinity create density gradients, leading to thermohaline circulation or deep-ocean currents [5]. The shape and configuration of coastlines, along with the topography of the ocean floor, further influence the direction and speed of these currents [6]. While the Earth's rotation is a critical cause—generating the Coriolis force that deflects currents [4]—the Earth's revolution (its orbital motion around the Sun) is not a direct cause of ocean current generation. Revolution primarily affects seasonal cycles and solar radiation distribution but does not provide the mechanical or density-driven force required to move ocean water masses directly, unlike rotation or wind systems.

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 32: Ocean Movements Ocean Currents And Tides > Influence Of Wind (Atmospheric Circulation) > p. 487
2. [2] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 12: The Oceans > The Movements of Ocean Currents > p. 110
3. [5] https://oceanexplorer.noaa.gov/ocean-fact/currents/
4. [6] https://education.nationalgeographic.org/resource/ocean-currents-and-climate/
5. [4] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 33: Ocean temperature and salinity > Thermohaline Circulation > p. 514