Explanation: The Indian monsoon is a complex weather system that brings significant rainfall to the Indian subcontinent. It is characterized by a seasonal reversal of wind patterns, with the southwest monsoon bringing moisture-laden winds from the Indian Ocean to India. The monsoon can be divided into two main branches: the Bay of Bengal branch and the Arabian Sea branch.
The Bay of Bengal branch of the monsoon primarily affects the eastern coast of India, including regions like Odisha, West Bengal, and parts of Northeast India. This branch of the monsoon is responsible for the heavy rainfall experienced in these areas during the monsoon season. It does not significantly impact the west coast of India.
The Arabian Sea branch of the monsoon, on the other hand, affects the western coast of India, including the states of Gujarat, Maharashtra, Goa, Karnataka, and Kerala. This branch of the monsoon is responsible for the rainfall received by the Western Ghats, a mountain range that runs parallel to the western coast of India. The Western Ghats play a crucial role in the orographic effect, which is a process where moist air is forced to rise over mountains, leading to the condensation of water vapor and the formation of clouds and precipitation.
Orographic rainfall is a significant source of precipitation in the Western Ghats. As the moist air from the Arabian Sea branch of the monsoon moves towards the Western Ghats, it is forced to rise due to the elevation of the mountains. This rising air cools, leading to the condensation of water vapor and the formation of clouds, which then result in heavy rainfall on the windward side of the Western Ghats. This process is a key factor in the high rainfall received by the Western Ghats and the surrounding regions.
The plains of north India, such as those in Uttar Pradesh, Bihar, and parts of Madhya Pradesh, receive their rainfall primarily from the Bay of Bengal branch of the monsoon, not from the Arabian Sea current. The Arabian Sea branch of the monsoon does not directly impact the plains of north India.
In summary, the correct statement among the given options is that the rainfall along the Western Ghats is orographic. The Bay of Bengal branch of the monsoon does not cause rainfall on the west coast of India, and the Arabian Sea current does not bring rain to the plains of north India. Understanding the different branches of the monsoon and their respective impacts on different regions of India is crucial for comprehending the rainfall patterns in the country.