Here is your short essay on Indian Ocean

Investigations regarding the salinity are much less in Indian Ocean in comparison with the Atlantic and the Pacific Oceans. In the northwestern part of this ocean the surface salinity ranges from 32 to 37%.

The higher surface water salinity in this part of the ocean is due to the very saline water of the Red Sea and the Persian Gulf that reaches the northwestern area as a surface flow.

The surface salinity between the equatorial region and Arab Peninsula is more than 37%. On the contrary, the surface salinity in the northeastern part of this ocean is relatively lower- between 32% and 34%.

In fact, this part of the Indian Ocean, besides getting a large supply of fresh water from heavy precipitation, also receives enormous amount of non-saline fresh water from a number of large rivers falling into it.

However, the surface salinity from about 40°S latitude to the margin of the Antarctic gradually decreases. A large supply of fresh water is available from the melt water of the continental ice sheet and the ice bergs, and these results in lowering the surface salinity in this region.

The salinity decreases from 35% to 33.5%. The average surface salinity in the remaining part of the ocean is about 35 %. However, the surface salinity in the western part of this ocean is higher than that in the eastern part.

In the southern part of the Indian Ocean, salinity in the vicinity of the west coast of Australia is higher because of the high evaporation rate, since the climate in this area is marked by aridity. In this part of the ocean isohalines run parallel to the equator.

As we have seen earlier, near the mouths of large rivers falling into the ocean, the surface salinity is lowered. Near the mouths of the Ganges, Irrawadi and Euphrates and Tigris the surface salinity is 30%, 20% and 35% respectively. The surface salinity in the Bay of Bengal seldom exceeds 34%₀.

During the summer monsoon, when there is copious rainfall, the flood waters from the Ganges, Brahmputra and other large rivers along the coast of Burma and India dilute the water and reduce the surface salinity.

At the extreme northern part of the bay, salinity may be reduced to a very low value of 18%o. However, the major impact of the dilution is limited to the Indian coast, and offshore it is not so significant.