Which layer is extremely thin with an abundance of ions, and temperature increases with height?

Which layer is extremely thin with an abundance of ions, and temperature increases with height?

• A. Stratosphere
• B. Exosphere
• C. Thermosphere
• D. Ozone layer

Answer: (C)

In the upper atmosphere, solar radiation ionizes particles, creating many ions in a region where the air is extremely thin. This combination identifies the thermosphere. The temperature in this layer increases with height because high-energy sunlight heats the sparse gas, so as you go higher, the kinetic energy of the particles tends to be higher. The ion-rich nature here also links to the ionosphere that sits within this layer. In contrast, the ozone layer is located in the stratosphere and isn’t characterized by abundant ions, and the exosphere is even more diffuse and its temperature behavior is less straightforward.

In the upper atmosphere, solar radiation ionizes particles, creating many ions in a region where the air is extremely thin. This combination identifies the thermosphere. The temperature in this layer increases with height because high-energy sunlight heats the sparse gas, so as you go higher, the kinetic energy of the particles tends to be higher. The ion-rich nature here also links to the ionosphere that sits within this layer. In contrast, the ozone layer is located in the stratosphere and isn’t characterized by abundant ions, and the exosphere is even more diffuse and its temperature behavior is less straightforward.