Which provides evidence that radiation from the sun heats planet earth
There are several pieces of evidence that radiation from the sun heats planet Earth:
1. Temperature Distribution: The temperature of our planet varies greatly, with warm zones near the equator and colder regions near the poles. This distribution of temperature can be explained by the fact that sunlight is more direct and intense near the equator, resulting in higher temperatures.
2. Energy Balance: Earth's global energy balance refers to the balance between incoming solar radiation and outgoing thermal radiation. Scientists have measured the amount of solar radiation reaching Earth's atmosphere and found that it far exceeds the amount of energy that is emitted back into space. This energy imbalance is possible because the atmosphere traps a portion of the incoming solar radiation, preventing it from escaping into space.
3. Greenhouse Effect: The greenhouse effect is a natural process where certain gases in Earth's atmosphere, such as carbon dioxide and water vapor, absorb and trap some of the thermal radiation emitted by the Earth's surface. This absorption of thermal radiation by greenhouse gases allows the atmosphere to act as a heat-trapping blanket, keeping the planet warmer than it would be otherwise.
4. Solar Spectrum: Scientists have studied the spectrum of solar radiation and found that it closely matches the spectrum of thermal radiation emitted by a black body at a temperature of approximately 5800 Kelvin, which coincides with the estimated temperature of the sun's surface. This similarity in spectra provides strong evidence that solar radiation is responsible for heating the Earth.
5. Solar Energy Measurements: Solar energy can be directly measured using instruments like solar radiometers and pyranometers. These measurements consistently show that the amount of solar energy reaching Earth is sufficient to account for the observed warming of the planet.
Overall, these lines of evidence strongly support the understanding that radiation from the sun is the primary source of heat for planet Earth.