Question

. State three differences between onset of Monsoon and withdrawal of Monsoon

Answer 1

Answer:

The onset of the Indian Monsoon and Withdrawal is defined in terms of zonal asymmetric temperature anomaly and withdrawal is defined in terms of vertical wind shear. The Monsoon, unlike the trades, are not steady winds but are pulsating in nature, affected by different atmospheric conditions encountered by it, on its way over the warm tropical seas. The duration of the monsoon is between 100- 120 days from early June to mid-September. Around the time of its arrival, the normal rainfall increases suddenly and continues constantly for several days. This is known as the ‘burst’ of the monsoon, and can be distinguished from the pre-monsoon showers. The monsoon arrives at the southern tip of the Indian peninsula generally by the first week of June. Subsequently, it divides into two – the Arabian Sea branch and the Bay of Bengal branch.

The Arabian Sea branch reaches Mumbai about ten days later on approximately the 10th of June. This is a fairly rapid advance. The Bay of Bengal branch also advances rapidly and arrives in Assam in the first week of June. The lofty mountains cause the monsoon winds to deflect towards the west over the Ganga plains. By mid-June the Arabian Sea branch of the monsoon arrives over Saurashtra-Kuchchh and the central part of the country. The Arabian Sea and the Bay of Bengal branches of the monsoon merge over the north-western part of the Ganga plains. Delhi generally receives the monsoon showers from the Bay of Bengal branch by the end of June (tentative date is 29th of June).

Answer 2

Answer: Onset of Monsoon: Due to the rapid rise in the temperature in May over north west India the air pressure decreases and the low pressure is established there. To fill up this area of low pressure the air is suck in from the Arabian Sea and Bay of Bengal.

Withdrawl of Monsoon: By the end of September the south west monsoon becomes weak as the low pressure trough shift southward. By the beginning of october the low pressure centres over northern parts move over the bay of bengal and by early november it moves over Karnataka and Tamil Nadu.