North Easterly Winds
Explanation
The general circulation of the atmosphere consists of planetary wind systems that blow from high-pressure belts to low-pressure belts. India’s latitudinal position places it primarily within the tropical and subtropical zones of the Northern Hemisphere.- North Easterly Winds: India lies in the region of north easterly winds. These winds originate from the subtropical high-pressure belt of the northern hemisphere. They blow southwards towards the equatorial low-pressure belt. Due to the rotation of the earth (Coriolis force), they are deflected to the right, becoming North Easterly Trade Winds.
- Seasonal Variation: Although the planetary wind belt is North Easterly, the pressure conditions over the Indian subcontinent change seasonally. During winter, these winds prevail as the dry North East Monsoon. During summer, a low-pressure area develops over interior Asia and North-West India, causing a complete reversal of wind direction to the South West Monsoon. However, the fundamental planetary wind belt associated with India's latitude is the North Easterly Trades.
Analysis of Incorrect Options:
- South Westerly Westerlies South Westerly Westerlies: These winds blow in the mid-latitudes (between $30^\circ$ and $60^\circ$ latitude) in both hemispheres. India lies south of this belt.
- Polar Easterlies Polar Easterlies: These are cold, dry winds blowing from the polar high-pressure areas to the sub-polar low-pressure areas (above $60^\circ$ latitude).
- South Easterly Trade Winds (throughout the year) South Easterly Trade Winds: These winds originate in the Southern Hemisphere. While they cross the equator and become the South West Monsoon affecting India in summer, India does not lie in the region of South Easterly winds throughout the year.
Key Takeaway: India is geographically situated in the belt of the North Easterly Trade Winds, which blow from the Subtropical High Pressure belt towards the Equatorial Low Pressure belt.