Consider the following statements with reference to structure of the Earth's atmosphere : 1. Thickness of the troposphere is greatest at the equator 2. The air temperature of the tropopause is highest above the poles 3. The temperature in troposphere decreases at the rate of 1ºF for every 165 m of height Which of the statements given above is/are correct ?

Statement 1 is correct as the troposphere's thickness is greatest at the equator (18 km) due to intense convective heating and vertical expansion, compared to only 8 km at the poles [3]. Statement 2 is correct because the tropopause temperature is actually higher above the poles (approximately -45°C) than above the equator (approximately -80°C) [5]. This occurs because the greater vertical extent of the troposphere at the equator allows for a longer duration of temperature decline before reaching the tropopause [2]. Statement 3 is incorrect; while the temperature decreases with height, the standard normal lapse rate is 1°C for every 165 m (or 6.5°C per km), not 1°F [5]. Therefore, only statements 1 and 2 are accurate representations of the Earth's atmospheric structure.

Sources

1. [1] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 1: BASIC CONCEPTS OF ENVIRONMENT AND ECOLOGY > Structure of the Atmosphere > p. 7
2. [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 20: Earths Atmosphere > Troposphere (0 to 12 km) > p. 274
3. [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 20: Earths Atmosphere > Troposphere (0 to 12 km) > p. 275
4. [5] https://egyankosh.ac.in/bitstream/123456789/103159/3/Block-2.pdf