The correct option is 2 and 3 only.
Explanation
The spatial distribution of ocean surface temperatures is primarily governed by latitude (insolation), the unequal distribution of land and water, and atmospheric conditions such as cloud cover. While temperature generally decreases from the equator to the poles, specific anomalies exist due to hemispheric differences.
Statement 1 is Incorrect:
The highest ocean surface temperatures are not recorded exactly at the equator. They are typically observed slightly north of the equator. This is because the equatorial region experiences heavy cloudiness and frequent precipitation, which reduces the amount of direct solar insolation reaching the surface. The highest temperatures are usually found in the tropics, where skies are clearer.
Statement 2 is Correct:
The oceans in the Northern Hemisphere record relatively higher average temperatures (approximately 19°C) compared to the Southern Hemisphere (approximately 16°C). This is due to the dominance of landmasses in the Northern Hemisphere. Land heats up faster and more intensely than water, and this heat is transferred to the adjacent oceans, raising their average temperature.
Statement 3 is Correct:
Ocean surface temperature decreases with increasing latitude as the angle of solar insolation becomes more oblique. The average rate of this temperature decrease is generally accepted to be 0.5°C per degree of latitude.
Key Takeaway:
The thermal equator of the oceans lies north of the geographical equator, and the Northern Hemisphere oceans are warmer on average due to the influence of extensive landmasses.