NCERT Solutions for Understanding Society: India and Beyond (Part 1) Chapter 3 Atmosphere and Climate

What is atmosphere? Explain its composition with the help of a pie diagram.

Draw a labelled diagram of the structure of atmosphere.

Which are the four main seasons of India?

Why do you not feel the pressure of the atmosphere?

In which layer of the atmosphere do aeroplanes fly and why?

Distinguish between the following: a. The troposphere and stratosphere b. The south-west monsoon and north-east monsoon

Do it yourself: Table 3.3 shows the average monthly temperatures and rainfall amounts for 10 representative stations. Study these figures on your own and convert them into ‘temperature and rainfall’ graphs. The visual representations will help you grasp their similarities and differences at a glance. One such graph (Fig. 3.14) is already prepared for you. See if you can arrive at some broad generalisations about our diverse climatic conditions. 7.1. Now look at Table 3.3 again. Re-arrange the 10 stations according to their distance from the equator. 7.2 Find out: a. Two stations with the most extreme climate. b. Two stations influenced by retreating monsoons. c. The two hottest stations in the months of (i) February (ii) June 7.3. Now find out: a. Why does Shillong experience more rainfall than Kolkata? b. Why does Delhi receive more rainfall than Jodhpur? 58 Understanding Society: India and Beyond Grade 9 – Part 1 7.4. Now think why a. Thiruvananthapuram has an equable climate? b. Chennai has more rainfall only after the fury of the monsoon is over in most parts of the country? c. Leh has moderate precipitation almost throughout the year? Table 3.3. Average monthly temperatures and rainfall for 10 representative stations (temperature and rainfall data are representational) Stations Latitude Altitude (Metres) Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. Annual Rainfall Temperature (oC) Bengaluru Rainfall (cm) 12°58'N 909 20.5 22.7 25.2 27.1 26.7 24.2 23.0 23.0 23.1 22.9 18.9 20.2 0.7 0.9 1.1 4.5 10.7 7.1 11.1 13.7 16.4 15.3 6.1 1.3 88.9 Temperature (oC) Mumbai Rainfall (cm) 19°N 11 24.4 24.4 26.7 28.3 30.0 28.9 27.2 27.2 27.2 27.8 27.2 25.0 0.2 0.2 – – 1.8 50.6 61.0 36.9 26.9 4.8 1.0 – 183.4 Temperature (oC) Kolkata Rainfall (cm) 22°34'N 6 19.6 22.0 27.1 30.1 30.4 29.9 28.9 28.7 28.9 27.6 23.4 19.7 1.2 2.8 3.4 5.1 13.4 29.0 33.1 33.4 25.3 12.7 2.7 0.4 162.5 Temperature (oC) Delhi Rainfall (cm) 29°N 219 14.4 16.7 23.3 30.0 33.3 33.3 30.0 29.4 28.9 25.6 19.4 15.6 2.5 1.5 1.3 1.0 1.8 7.4 19.3 17.8 11.9 1.3 0.2 1.0 67.0 Temperature (oC) Jodhpur Rainfall 26°18'N 224 16.8 19.2 26.6 29.8 33.3 33.9 31.3 29.0 20.1 27.0 20.1 14.9 0.5 0.6 0.3 0.3 1.0 3.1 10.8 13.1 5.7 0.8 0.2 0.2 36.6 Temperature (oC) Chennai Rainfall (cm) 13°4'N 7 24.5 25.7 27.7 30.4 33.0 32.5 31.0 30.2 29.8 28.0 25.9 24.7 4.6 1.3 1.3 1.8 3.8 4.5

7 11.3 11.9 30.6 35.0 13.9 128.6 Temperature (oC) Nagpur Rainfall (cm) 21°9'N 312 21.5 23.9 28.3 32.7 35.5 32.0 27.7 27.3 27.9 26.7 23.1 20.7 1.1 2.3 1.7 1.6 2.1 22.2 37.6 28.6 18.5 5.5 2.0 1.0 124.2 Temperature (oC) Shillong Rainfall (cm) 24°34'N 1461

8 11.3 15.9 18.5 19.2 20.5 21.1 20.9 20.0 17.2 13.3 10.4 1.4 2.9 5.6 14.6 29.5 47.6 35.9 34.3 30.2 18.8 3.8 0.6 225.3 Temperature (oC) Thiruvananthapuram Rainfall (cm) 8°29'N 61 26.7 27.3 28.3 28.7 28.6 26.6 26.2 26.2 26.5 26.7 26.6 26.5 2.3 2.1 3.7 10.6 20.8 35.6 22.3 14.6 13.8 27.3 20.6 7.5 181.2 Temperature (oC) Leh Rainfall (cm) 34°N 3506 –8.5 –7.2 –0.6 6.1 10.0 14.4 17.2 16.1 12.2 6.1 0.0 –5.6 1.0 0.8 0.8 0.5 0.5 0.5 1.3 1.3 0.8 0.5 – 0.5 8.5 59 3 – Atmosphere and Climate 0 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 5 5 10 10 15 15 20 20 25 30 35 Temperature (oCelsius) Rainfall (Centimetres) Fig. 3.14. Temperature and Rainfall of Delhi 7.5. Despite these differences across regions, can you observe any substantial evidence to conclude that the monsoons provide a very strong framework, lending overall climatic unity to the whole country? 8. Collect pictures of houses and clothing of people from different regions of India. Examine whether they reflect any relationship with the climatic conditions or the relief of those regions. 60 Understanding Society: India and Beyond Grade 9 – Part 1 Notes