Question

what is mean by set up monsoon

Answer 1

Monsoon  is traditionally defined as a seasonal
reversing wind accompanied by corresponding changes in precipitation,but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with the asymmetric heating of land and sea.Usually, the term monsoon is used to refer to the rainy phase of a seasonally changing pattern, although technically there is also a dry phase. The term is sometimes incorrectly used for locally heavy but short-term rains,although these rains meet the dictionary definition of monsoon.

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Answer 2

$\huge\tt{ANSWER\::-}$

By the beginning of June, the arrival of Arabian sea branch and Bay of Bengal branch in India is called onset of the monsoon