The correct option is Long wave radiation.
Explanation
The wavelength of electromagnetic radiation emitted by a body is inversely proportional to its temperature (Wien’s Displacement Law). Hotter bodies emit energy in shorter wavelengths, while cooler bodies emit energy in longer wavelengths.
Detailed Analysis:
- Incoming Solar Radiation: The Sun has an extremely high surface temperature (approximately 6,000°C). Consequently, the energy reaching the Earth (insolation) is primarily in the form of shortwave radiation, which includes the visible light spectrum and ultraviolet rays.
- Outgoing Terrestrial Radiation: The Earth absorbs shortwave solar energy and warms up. Since the Earth is a much cooler body compared to the Sun, it radiates energy back into the atmosphere in the form of longwave radiation (specifically infrared radiation).
- Atmospheric Interaction: The atmosphere is largely transparent to incoming shortwave radiation but is opaque to outgoing longwave radiation. Greenhouse gases (such as carbon dioxide and water vapor) absorb this longwave terrestrial radiation, thereby heating the atmosphere from below.
Key Takeaway: Incoming energy from the Sun is shortwave, while outgoing energy radiated by the Earth is longwave (infrared).