Topic– Part of static series under the heading – Monsoon break
1) Explain what happens during break monsoon period and the reason why break in monsoon occurs?(250 words)
Key demand of the question
The question expects us to explain what break in monsoon is, the characteristic feature of monsoon break and the reasons why break in monsoon happens.
Structure of the answer
Introduction – Explain what break monsoon is – During the Monsoon season, there are periods when the Monsoon trough shifts closer to the foothills of Himalayas, which leads to sharp decrease in rainfall over most parts of the country. However, rainfall increase along the foothills of Himalayas, Northeast India and parts of the Southern Peninsula. Such a synoptic situation is known as the ‘break’ Monsoon period.
Body
- Explain its characteristic feature. These breaks in the different regions are due to different reasons:
- In northern India rains are likely to fail if the rain-bearing storms are not very frequent
along the monsoon trough or the ITCZ over this region.- Over the west coast the dry spells are associated with days when winds blow parallel to
the coast.- Explain the reasons why break in monsoon occurs – When tropical disturbances advance along the monsoon trough, sometimes the sea level low pressure area weakens and making the low pressure area from 900 mb to 700 mb height to move north of the trough. As the high level low pressure area moves north, precipitation decreases in the northern plains. This makes the low pressure area over North Bay of Bengal to be replaced with a high pressure area. This makes the monsoon trough along the west coast to weaken and monsoon winds from Bay of Bengal branch alone feed the monsoon trough which runs along the foothill of Himalayas and North east India. This results in less or no rainfall across west coast, Deccan plateau and Northern plains. But a low pressure trough forms over the Tamil Nadu coast increasing the rainfall. As the monsoon trough runs close to foothills of Himalayas, monsoon winds ascend the slopes of Himalayas resulting in orthographic rainfall. This is how a monsoon break works.
