Monsoon
Explanation
Winds are broadly classified into three categories based on their periodicity and area of influence: Primary (Permanent or Planetary) winds, Secondary (Periodic or Seasonal) winds, and Tertiary (Local) winds. Permanent winds blow constantly throughout the year in a fixed direction over the globe.Analysis of Options:
- Westerlies: These are permanent winds blowing from the Sub-Tropical High-Pressure Belts towards the Sub-Polar Low-Pressure Belts in both hemispheres. They prevail throughout the year.
- Easterlies: Also known as Polar Easterlies, these are permanent winds that blow from the Polar High-Pressure Belts towards the Sub-Polar Low-Pressure Belts.
- Trade Winds Trade Winds: These are permanent winds blowing from the Sub-Tropical High-Pressure Belts towards the Equatorial Low-Pressure Belt. They are known for their consistency in force and direction.
- Monsoon: Monsoons are classified as secondary or periodic winds. They are characterized by a complete seasonal reversal of wind direction (blowing from sea to land during summer and land to sea during winter). Therefore, they are not permanent winds.
Key Takeaway: The planetary wind system (Trade Winds, Westerlies, and Polar Easterlies) operates year-round, whereas Monsoons are seasonal winds driven by the differential heating of land and sea.