Solar radiation is radiant (electromagnetic) energy from the sun. It provides light and heat for the Earth and energy for photosynthesis. This radiant energy is necessary for the metabolism of the environment and its inhabitants.
Radiation from sun
Radiation from the sun is commonly known as sunlight which is a mixture of infrared waves to ultraviolet rays. These rays are electromagnetic waves.
Heating of Earth
Heating of the earth takes place when the surface of the earth receives the incoming solar radiation. Some of the radiation gets reflected back into the atmosphere and clouds. When the matter absorbs energy which results in heating of the materials.
- Earth absorbs infrared radiation and converts it to thermal energy. As the surface absorbs heat from the sun, it becomes warmer than the surrounding atmosphere.
- The heat is then transferred by conduction (contact) from the warmer Earth to the cooler atmosphere.
- The rising warm air is often referred to as a thermal.
- As the warmed air rises, cooler air sinks to the surface, where it continues in the convection process.
The longer wavelengths from the sun causes heat by exciting electrons in the substances that are absorbed by them. Thus, the infrared radiation is responsible for warming the earth’s surface. Infrared light is reflected more than ultraviolet or visible light due to its longer wavelengths. This reflection allows infrared radiation to transfer heat between the surface, water and the air which causes the heating effect.