Question

Describe the progress of the monsoon winds over India during the rainy season.

Answer 1

As India is surrounded by Bay of Bengal on the east and the Arabian Sea on the west, south-west monsoons in India arrive as Bay of Bengal branch and Arabian Sea branch.

• Bay of Bengal branch is divided into two distinct streams:
  

1. First stream crosses Ganga-Brahmaputra delta and reaches Meghalaya, here the orographic effect causes intense rainfall of 1,102 cm from June to October.
   
2. Mawsynram and Cherrapunjee both the stations located on southern slopes of Khasi hills receive immense rainfall from this branch of monsoon.
   
3. The second stream of Bay of Bengal branch southwest monsoons move along the foot of Himalayas and are deflected to the west by the Himalayas and brings heavy rains to Gangetic plains.
   

• Arabian Sea branch is divided into three distinct streams:
  

1. First one strike perpendicular to the Western Ghats causing plentiful rainfall of about 400 to 500 cm annual rainfall on the windward side of Western Ghats.
   
2. The second stream enters Narmada-Tapti regions in central India but do not cause heavy rainfall because of the absence of an orographic obstacle.
   

The third stream moves parallel to the Aravali Range without causing much rainfall. Consequently, the whole of Rajasthan is a desert area.

By July end both these branches meet in the Northern part of India.