Question

the equatorial regions record high salinity as compared to polar regions. why?​

Answer 1

Answer:

Sea surface salinity is greatest not right along the equator, but rather in tropical regions just to the north and south of the equator. Surface and subsurface currents have different impacts on surface salinity in each ocean. For example, the Atlantic surface is generally more saline because less saline water sinks and flows beneath the surface in a subsurface current that is not as strong in other oceans. However, the global pattern of greater salinity in the non-equatorial tropics is due to global patterns of insolation (effective strength of solar radiation) and precipitation.

Insolation is greatest over the tropics, where the sun’s rays hit the surface more-or-less perpendicularly. As a result, more water evaporates from the tropical ocean’s surface, leaving water at the surface with higher salt concentrations.

Evaporation due to insolation is counterbalanced by precipitation. The area of greatest precipitation over the open ocean is within the Inter-Tropical Convergence Zone (ITCZ), a belt that circles Earth at or near the Equator. This belt shifts northward during the Northern Hemisphere summer (from March to September) and southward during the Southern Hemisphere summer (September to March), as the latitude where the sun is directly overhead shifts due to the tilt of Earth’s axis. This very strong insolation evaporates water at the surface and causes moist, hot air to rise, generating cloud formation and frequent, heavy rainfall. That rising air also pulls in moisture from neighboring tropical regions. Within the ITCZ, heavy rainfall strongly counterbalances evaporation, resulting in lower salinity than in tropical regions outside the ITCZ

Explanation:

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