Bay of Bengal and Arabian Sea salinity
Topic: Oceans: Hydrological Cycle, Relief of the Ocean Floor, Temperature and Salinity · NCERT: Class 11, Ch 12 "Water (Oceans)"
Meaning
The two seas on either side of India differ in salinity. The Bay of Bengal is fresher. Big rivers pour into it, including the Ganga, Brahmaputra, Irrawaddy, Mahanadi, Godavari and Krishna, and rain is heavy. The Arabian Sea is saltier. Evaporation is high, few rivers flow in, and salty water flows in from the Red Sea and Persian Gulf. The Bay's fresh top layer floats on saltier water below and stops the two from mixing. This keeps its surface warm, which helps cyclones form.
Example
After the monsoon, a thin layer of fresh river water spreads over the northern Bay of Bengal off the Ganga-Brahmaputra delta. This keeps the sea surface warm and helps the Bay produce more cyclones than the Arabian Sea.
Don't confuse with
- Sea surface temperature difference: the Bay is also warmer, but its low salinity is caused by rivers and rain. Its high temperature is partly a result of that fresh layer.
Related concepts
- Horizontal distribution of salinity
- Red Sea salinity
- Baltic Sea
- Mediterranean Sea salinity
- Halocline