Question

Which of the following statement(s) is/are true about the ocean circulation?

• A. Large-scale ocean surface currents are driven by winds.
• B. Cold, dense and salty water forms in the North Atlantic Ocean.
• C. Upwelling currents bring warm nutrient deficient water to the surface of the ocean.
• D. Thermohaline circulation does not transport energy in the meridional direction.

Hint:

Ocean circulation is driven by multiple factors, including wind, temperature, and salinity gradients. Upwelling typically brings cold, nutrient-rich water to the surface.

Answer 1

The Correct Option is A, B

(A) Large-scale ocean surface currents are driven by winds:
This statement is true. Large-scale ocean surface currents, such as the Gulf Stream and the Kuroshio Current, are primarily driven by the winds. The winds exert a force on the ocean's surface, transferring momentum and setting the water in motion. This wind-driven circulation is a major component of the global ocean circulation system. (B) Cold, dense and salty water forms in the North Atlantic Ocean:
This statement is also true. The North Atlantic Ocean is where cold, dense, and salty water is formed, particularly in the polar regions. The cold water in the North Atlantic becomes denser as it cools and becomes saltier due to the evaporation of water in this region. This dense water sinks and contributes to the global thermohaline circulation, which plays a key role in redistributing heat in the ocean. (C) Upwelling currents bring warm nutrient deficient water to the surface of the ocean:
This statement is false. Upwelling currents typically bring cold, nutrient-rich water to the surface, not warm, nutrient-deficient water. These cold waters, rich in nutrients like nitrogen and phosphorus, support biological productivity in regions where upwelling occurs, such as along the coasts of Peru, California, and parts of Africa. (D) Thermohaline circulation does not transport energy in the meridional direction:
This statement is false. Thermohaline circulation, also known as the "global conveyor belt," is responsible for transporting both heat and energy in the meridional (north-south) direction. It involves the movement of water masses driven by differences in temperature and salinity, helping to redistribute thermal energy across the planet. Thus, the correct answers are (A) and (B). Final Answer: \[ \boxed{\text{(A) Large-scale ocean surface currents are driven by winds.}} \text{and} \boxed{\text{(B) Cold, dense and salty water forms in the North Atlantic Ocean.}}. \]