Correct Option
The correct option is 2 only
Explanation
Ocean salinity refers to the total content of dissolved salts in seawater, usually expressed in parts per thousand (ppt). The distribution of salinity is primarily determined by the balance between evaporation and precipitation, as well as the influx of fresh water from rivers and melting ice.
Statement-wise Analysis
- Statement 1 is Incorrect: The Atlantic Ocean is generally the saltiest of the major oceans. Its average salinity is approximately 36 ppt (parts per thousand), which is slightly higher than the global ocean average of 35 ppt. This is largely due to the trade winds carrying water vapor from the Atlantic to the Pacific and the high rate of evaporation in the tropical and subtropical regions.
- Statement 2 is Correct: The highest salinity is not recorded at the equator. Although temperatures are high at the equator, heavy daily rainfall and high humidity add fresh water to the ocean surface, thereby lowering the salinity. The highest salinity is observed in the sub-tropical high-pressure belts (between 20° N and 30° N/S), where evaporation exceeds precipitation due to clear skies and high temperatures.
- Statement 3 is Incorrect: Maximum salinity is not observed in the polar regions. In fact, salinity is very low in polar areas (ranging between 20 and 32 ppt) due to the influx of large amounts of fresh water from melting ice caps and the low rate of evaporation caused by extremely low temperatures.
Key Takeaway
Key Takeaway: Ocean salinity is highest in the sub-tropical latitudes (20°-30°) due to high evaporation and low precipitation. It decreases at the equator due to heavy rainfall and drops significantly in polar regions due to ice melt and low evaporation.