The atmosphere is heated in several ways - heat from the core of the Earth, by radiation from the Sun, conduction from contact with warm land and water, convection to even out the temperature and by absorption of infrared radiation from the warm land and water. ✓Convection then spreads and evens out the heat.

Convection: The process of heating the atmosphere

The correct answer to the question is option 'B' - convection. Convection is the process through which the atmosphere of the Earth is heated. Let's delve into the details of how convection works and why it is the primary mechanism for heating the atmosphere.

Explanation

1. What is convection?
Convection is a mode of heat transfer that occurs through the movement of fluid (liquid or gas). In the case of the Earth's atmosphere, the fluid is air. Convection involves the transfer of heat energy by the movement of hot air rising and cooler air sinking.

2. How does convection heat the atmosphere?
- The Sun is the primary source of heat for the Earth's atmosphere. Sunlight contains electromagnetic radiation, including visible light and infrared radiation.
- When sunlight reaches the Earth's surface, it heats the Earth's surface. The heated surface, in turn, transfers some of its heat energy to the air in contact with it.
- As the air near the surface gets heated, it becomes less dense and starts to rise. This rising hot air creates areas of low pressure near the surface.
- The cooler air from higher altitudes, which is denser, moves in to replace the rising hot air. This cooler air gets heated by the Earth's surface, creating a continuous cycle of convection.
- This convection cycle is responsible for the mixing of heat energy throughout the atmosphere, resulting in the heating of the entire atmosphere.

3. Why is convection the primary mechanism for heating the atmosphere?
- While radiation from the Sun does directly heat the atmosphere, it primarily heats the Earth's surface. The heated surface then transfers its heat to the air through convection.
- Conduction is another mode of heat transfer, but it is not the primary mechanism for heating the atmosphere. Conduction involves the transfer of heat through direct contact between objects, but the density of air is much lower compared to solids and liquids, limiting the effectiveness of conduction in heating the atmosphere.
- Emission refers to the release of electromagnetic radiation from a material, and while it plays a role in the overall energy balance of the Earth, it is not the main process responsible for heating the atmosphere.

Conclusion

In summary, the atmosphere of the Earth is primarily heated by the process of convection. The Sun's radiation heats the Earth's surface, which, in turn, transfers heat to the air through convection. This continuous cycle of rising hot air and sinking cooler air creates a mixing of heat energy throughout the atmosphere, resulting in the overall heating of the Earth's atmosphere.