Periodic Winds

  • The direction of these winds changes with the change of seasons.
  • Monsoon winds are the most important periodic winds.


Monsoon Winds:

  • The word ‘Monsoon’ has been derived from the Arabic word ‘Mausim’ meaning season.
  • The winds that reverse their direction with the change of seasons are called monsoon winds.
  • During summer the monsoon winds blow from sea towards land and during winter from land towards seas.
  • Traditionally these winds were explained as land and sea breezes on a large scale. But this explanation does not hold good now.
  • Now a days the monsoon is generally accepted as seasonal modification of the general planetary wind system.
  • The Asiatic monsoon is the result of interaction of both planetary wind system and regional factors, both at the surface and in the upper troposphere (see fig. 11.8)
  • India, Pakistan, Bangladesh, Myanmar(Burma), Sri Lanka, the Arabian Sea, the Bay of Bengal, South-east Asia, North Australia, China and Japan are important regions where monsoon winds are prevalent.