ThinkRankClimate
Overview
The chapter explains India’s monsoon climate and the factors that control rainfall and temperature. It shows why monsoon variability is crucial for agriculture and water security.
Learning Objectives
- Explain factors affecting India’s climate
- Describe the mechanism of monsoon winds
- Understand uneven rainfall distribution
Key Concepts
Climatic Controls
Latitude, altitude, pressure systems, winds, and ocean currents collectively shape India’s climate.
Pressure and Wind Systems
Seasonal pressure differences between land and sea drive wind reversal, creating the monsoon cycle.
Monsoon Mechanism
Seasonal heating causes pressure reversal, bringing moisture-laden winds from the ocean in summer and dry winds in winter.
Orographic Rainfall
Mountains force moist winds to rise, causing heavy rain on windward slopes and dry conditions on leeward sides.
Jet Streams and Western Disturbances
Jet streams guide monsoon winds, while western disturbances bring winter rainfall to northwestern India.
Rainfall Variability
Rainfall is high in the Western Ghats and Northeast but low in Rajasthan and interior plateaus.
El Nino Impact
El Nino events weaken monsoons, increasing drought risk.
Key Terms
Examples
Western Ghats Rainfall
Moist winds rise over the Ghats, causing heavy orographic rainfall.
Rajasthan Dry Climate
Distance from sea and Aravalli orientation reduce rainfall in the desert region.
Quick Check
- What drives the monsoon winds?
- Why is rainfall uneven in India?
- How does El Nino affect monsoon?