The significance of radiation from the sun to the earth

The sun radiation refers to the emission of electromagnetic waves and particles into space. Arrived in the earth's atmosphere upper bound of the solar radiation energy called geographic solar radiation.

in the earth in solar-terrestrial evenly spacing, perpendicular to the upper and lower bounds of the earth's atmosphere by the sun's rays in unit time per unit area of full spectrum total energy by solar radiation, known as the solar constant. The commonly used unit of solar constant is w/m 2. On the basis of different observation methods and techniques, sun constant value is different. And the change of solar activity and the solar-terrestrial space the solar radiation energy of the upper and lower bounds of the earth's atmosphere.

the sun radiation through the atmosphere, some of the arrived in the earth, and called the direct solar radiation; Another part of the molecules, the atmosphere to the atmosphere dust, moisture absorption, scattering and reflection. Part by scattering solar radiation back to space, arrived in the earth, and the other part in this part of the earth is called scattering solar radiation. Arrived in scattering solar radiation on the ground and direct solar radiation, known as the sum of total radiation. After the sun radiation through the atmosphere, the intensity and the spectral energy distribution is changing. Arrived in the earth's solar radiation energy is much smaller than the upper atmosphere, the energy distribution in the solar spectrum in the uv spectral region almost extinct, 40% cuts in the visible spectrum, but in the infrared spectral region increased to 60%.

the sun radiation is the first history of the earth's surface energy, arrived in the solar radiation energy on the earth as long as a small part of, but its effect is considerable. People's perceptions of the solar radiation effect is the most direct from it is the first power of people to produce and life. As plants need light and heat, industry a lot of use of fossil fuels such as coal, oil is solar energy conversion, and solar oven, solar dryer, solar street light, solar power, solar cells, etc.