Introduction to Indian Climate and Weather

Key Topics Covered

• Difference between climate and weather
• Key elements determining climate
• Influence of Tropic of Cancer and Himalayas on Indian climate
• Monsoon mechanism and its significance

Climate vs. Weather

• Weather: State of atmosphere at a specific place and time, can vary even within a day.
• Climate: Long-term average of weather patterns over a larger area, typically over 30 years.
• Elements affecting climate: atmospheric pressure, temperature, wind, humidity, precipitation.

Factors Influencing Indian Climate

• Tropic of Cancer: Divides India into northern temperate and southern tropical zones.
• Himalayas: Acts as a barrier protecting India from cold Central Asian winds and helps in monsoon formation.
• Monsoon Type Climate: India has a monsoon type climate, influenced by global climatic regions.

Variations in Climate

• Temperature Variation:
  • Northern India experiences extreme temperature variations.
  • Rajasthan can reach 50°C in summer; Kargil can drop to -45°C in winter.
  • Southern India has a more consistent, moderate temperature.
• Rainfall Variation:
  • Mawsynram in Meghalaya receives highest rainfall (~1180 cm).
  • Rajasthan and Leh receive minimal rainfall (~25 cm).
  • Western coast receives heavy rainfall during monsoon; eastern coast during winter rains.

Factors Affecting Temperature

• Latitude: Proximity to equator affects temperature (direct sunlight vs. poles).
• Altitude: Higher altitude = lower temperature.
• Distance from Sea: Coastal areas have moderate temperatures; interiors experience extremes.

Monsoon and Its Mechanism

• Origin: Derived from Arabic "Mausim," meaning season.
• Mechanism: Land-sea breeze and differential heating cause monsoon winds.
  • In summer, low pressure over land draws in moist winds from sea, causing rain.
  • Winds from southeast become southwest monsoon winds after crossing the equator.
  • Himalayas prevent monsoon winds from escaping, causing rain in India.

Conclusion

• Indian climate is influenced by multiple factors leading to diverse weather conditions across regions.
• Monsoon acts as a unifying element despite regional climatic variations.
• Next session will delve deeper into monsoon mechanisms.

Homework

• Which place receives the highest rainfall? Options: Cherrapunji, Mawsynram, Assam, Guwahati.

Note: For questions and doubts, students are encouraged to comment or attend the next session.