Most of the energy that reaches planet Earth comes from the sun, in the form of electromagnetic radiation. Depending on the length of the waves, they are more or less intense. Thus, for example, ultraviolet radiation, being very short (360 nanometers), carries a lot of energy, unlike radio waves whose waves are very long.
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Not all the radiation that reaches us from the sun is absorbed by the planet in the same way. In fact, only 26% is directly absorbedWhile the atmosphere will absorb the equivalent of 16%. It is also reflected, for example, by the materials on the planet (10%) or by clouds (24%).
In addition, solar radiation does not reach every corner the same. In fact, the rays are more absorbed around the equator, while at the poles they are much weaker, something that directly influences the climate of the place. In the upper map you can see in detail the solar energy that each corner of our planet receives. In many areas, high energy is usually related to low rainfall, as in the Sahara desert; but in others you can see a great explosion of life, as in the Amazon.
Solar electromagnetic radiation is distributed in a wide range of frequencies, which are:
- Ultraviolet radiation: represents 8-9% of the total energy.
- Visible range: represents 46-47% of the energy received.
- Near infrared ranges: represents 45%.
The atmosphere, as we said, has a very important role in the intensity and composition of radiation. We must also know that depending on ground movements, as well as temporal variations, the intensity may vary. For example, the northern hemisphere during the month of June approaches the sun, while the southern hemisphere moves further away. Thanks to these movements we can calculate when the seasons begin, something that will undoubtedly help us plan our vacations.