Question map
Which one of the following layers of atmosphere has high concentration of ions?
Explanation
The atmosphere is divided into layers based on temperature and chemical properties. The thermosphere, which begins at approximately 80 km above the Earth's surface, is characterized by a dramatic increase in temperature with altitude [3]. Within this region lies the ionosphere, an electrified layer extending from about 80 km to 400 km [4]. This layer contains a high concentration of ions and free electrons, formed when atoms and molecules absorb high-energy solar radiation such as X-rays and extreme ultraviolet (EUV) rays [4]. These charged particles are essential for global communication as they reflect and modify radio waves, allowing for long-distance skywave transmission [4]. While the exosphere also contains charged particles, the primary functional layer defined by its high ion concentration and its interaction with solar radiation is the ionosphere, which is embedded within or coincides with the thermosphere [3].
Sources
- [3] https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/exosphere
- [2] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 7: Composition and Structure of Atmosphere > STRUCTURE OF THE ATMOSPHERE > p. 65
- [4] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 20: Earths Atmosphere > Ionosphere (80 to 400 km) > p. 278
- [1] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 1: BASIC CONCEPTS OF ENVIRONMENT AND ECOLOGY > Structure of the Atmosphere > p. 8