Question

Western Boundary Current in the ocean is primarily due to

• A. Ekman pumping.
• B. Rotation of the earth.
• C. River water forcing.
• D. Ocean floor topography.

Hint:

The Coriolis effect, caused by the Earth's rotation, is responsible for the formation of strong western boundary currents in the ocean.

Answer 1

The Correct Option is B

Western boundary currents in the ocean, such as the Gulf Stream and the Kuroshio Current, are some of the strongest and most important currents that play a key role in ocean circulation. These currents are primarily driven by the Coriolis effect, which is the result of the Earth's rotation. The Coriolis effect causes moving fluids, including air and ocean currents, to be deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This deflection leads to the formation of narrow, fast-moving currents along the western edges of ocean basins, forming the western boundary currents. The formation of these western boundary currents is a direct result of the rotation of the Earth, not due to Ekman pumping, river water forcing, or ocean floor topography. Let's analyze the options: Ekman pumping (Option A): Ekman pumping is a phenomenon that results in the vertical movement of water due to wind stress. It is crucial for upwelling and downwelling processes but is not directly responsible for the formation of western boundary currents, which are primarily driven by the Earth's rotation. Rotation of the Earth (Option B): As previously explained, the Earth's rotation causes the Coriolis effect, which plays a major role in the formation of western boundary currents. This is the correct answer. River water forcing (Option C): River water can influence coastal currents, but it does not primarily drive the formation of western boundary currents, which are large-scale ocean currents. Ocean floor topography (Option D): While the topography of the ocean floor can influence the direction and speed of currents, it is not the main driver of western boundary currents. The main factor is the Earth's rotation, which causes the deflection of water masses along the western edges of ocean basins. Thus, the primary cause of the western boundary currents in the ocean is the rotation of the Earth, which leads to the Coriolis effect. This is why the correct answer is (B). Final Answer: \[ \boxed{\text{(B) Rotation of the earth.}}. \]