The sun is the primary source of heat to the earth and its atmosphere. The heats received from other celestial bodies as well as the interior of the earth are rather too insignificant to merit our attention.
The distance that separates the earth from the sun is about 1, 49,000, 000 kilometres. The diameter of the sun measures roughly about 13, 82,400 kilometres. The surface temperature of the sun is estimated between 5500o C and 6100o C. (or 5762oK)- Interice 8x106 to 40x1006 k.
Solar radiation provides more than 99.9 percent of the energy that heats the earth. Undoubtedly, the radiant energy from the sun is the most important control of our weather and climate.
The most astonishing fact about the incoming solar radiation (insolation) that strikes the earth's surface is that it is equal to about 23 billion horse power.
Actually it is this amount of energy received from the sun that acts as the driving force for all the atmospheric as well as biological processes on the earth. Besides, all other sources of energy found on earth such as coal, oil and wood etc. are nothing but converted form of solar energy.
The word 'insolation' is contraction of "incoming solar radiation". Radiant energy from the sun that strikes the earth is called insolation.
francis1897 answered the question on January 11, 2023 at 06:39