Question map
Which one of the following zones of the atmosphere is rich in ozone gas ?
Explanation
The Earth's atmosphere is divided into several layers, with the stratosphere being the zone specifically rich in ozone gas. Approximately 90% of the total atmospheric ozone resides in the stratosphere, primarily between altitudes of 15 km and 35 km [t1][t3][t7]. This region is commonly referred to as the 'ozone layer' or 'ozonosphere' [c1][t4]. Ozone in this layer is formed naturally when ultraviolet (UV) radiation splits oxygen molecules (O2) into individual atoms, which then combine with other O2 molecules to form O3 [c1][t2]. This stratospheric ozone plays a critical role in shielding life on Earth by absorbing harmful UV radiation, which also causes temperatures to increase with altitude in this layer [c3][t4][t5]. While about 10% of ozone exists in the troposphere as a pollutant, the highest concentration and the protective 'good' ozone are characteristic features of the stratosphere [c4][t1].
Sources
- [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 20: Earths Atmosphere > Ozonosphere > p. 276
- [2] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 7: Composition and Structure of Atmosphere > STRUCTURE OF THE ATMOSPHERE > p. 65
- [3] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 19: Ozone Depletion > OTSNE $$FUETION > p. 267
- [4] https://csl.noaa.gov/assessments/ozone/2010/twentyquestions/Q1.pdf
- [5] https://ozonewatch.gsfc.nasa.gov/facts/SH.html
- [6] https://ozone.unep.org/ozone-and-you