Climate

This geography chapter explains the climate of India, described as the monsoon type. You will distinguish weather, the state of the atmosphere at a given time, from climate, the average weather over more than thirty years. You will study the factors controlling climate: latitude, altitude, pressure and wind system, distance from the sea, ocean currents and relief, and see why India shows contrasts, from about 50 degrees Celsius in Churu in Rajasthan on a June day to minus 45 degrees Celsius in Drass in Ladakh in December, and from very heavy rainfall at Mawsynram in Meghalaya to scanty rain in western Rajasthan. You will learn how the monsoon works, through the differential heating of land and sea, the shift of the Inter Tropical Convergence Zone, the heating of the Tibetan plateau, jet streams and El Nino. The monsoon arrives in Kerala around 1 June and covers India by mid-July. You will study the four seasons, including the loo, mango showers and the retreating monsoon, and how the monsoon unifies the country.

Detailed Worksheet: Climate Section A - Definitions (10 marks) 1. Distinguish between weather and climate. (2 marks) 2. What is meant by the monsoon? From which word is it derived? (2 marks) 3. What is the Inter Tropical Convergence Zone (ITCZ)? (2 marks) 4. What is the loo? What are mango showers? (2 marks) 5. What is meant by the burst of the monsoon and a break in the monsoon? (2 marks) Section B - Calculations and Applications (15 marks) 6. The table shows mean monthly temperatures: Thiruvananthapuram, January 27 degrees Celsius and May 30 degrees Celsius; Delhi, January 14 degrees Celsius and May 33 degrees Celsius. Find the annual range of temperature for each, using these two months. Explain why the range is larger in Delhi. (3 marks) 7. Annual rainfall: Mawsynram about 1,190 cm, Mumbai about 240 cm, Delhi about 80 cm, Jaisalmer about 20 cm. How many times more rain does Mawsynram get than Delhi and than Jaisalmer? Arrange the places in decreasing order of rainfall. (3 marks) 8. The monsoon reaches Kerala on about 1 June and covers the entire country by about 15 July. How many days does it take to cover the country? Its withdrawal begins from north-western India in early September and is complete from the rest of the country by early December. Roughly how many months does the withdrawal take, and how long is the total period from onset in Kerala to complete withdrawal? (3 marks) 9. The Tropic of Cancer (23.5 degrees N) passes through India. Name four states it passes through. Find the latitudinal extent of India's mainland from about 8 degrees 4 minutes N to 37 degrees 6 minutes N. (3 marks) 10. Arrange the four seasons of India in order starting from December, with the months of each, and give one feature of each. (3 marks) Section C - Diagrams (10 marks) 11. On an outline map of India, show the areas receiving more than 400 cm and less than 60 cm of annual rainfall, and mark Mawsynram, Jaisalmer, Mumbai and Chennai. (4 marks) 12. On an outline map of India, show the directions of the Arabian Sea branch and the Bay of Bengal branch of the south-west monsoon. (3 marks) 13. Draw a climograph or bar graph of the monthly rainfall of Chennai showing peaks in October and November, and explain why it rains there in winter. (3 marks) Section D - Analysis and Higher-order Thinking (15 marks) 14. Explain the mechanism of the Indian monsoon using four factors: differential heating, ITCZ, Tibetan plateau and jet streams. How does El Nino affect it? (5 marks) 15. Explain why (i) the west coast gets more rain than the east coast in summer (ii) Tamil Nadu gets rain in winter (iii) the Thar desert receives very little rain (iv) the delta regions of the east coast get frequent cyclones (v) rainfall decreases from east to west in the northern plains. (5 marks) 16. Explain how the monsoon acts as a unifying bond for India, both in terms of agriculture and in the culture and festivals of the people. (5 marks) Instructions: Time allowed 2 hours. Attempt all sections. Use outline maps where asked and show working in data-based questions.