EVERYDAY SCIENCE

Detailed explanation-1: -The total power emitted by the sun is calculated by multiplying the emitted power density by the surface area of the sun. The sun has a radius of 695 x 106 m 4 giving a surface area of 6.07 x 1018 m2. Thus the total power output of the sun is 64 x 10 times 6.09 x 1018 m2, which is equal to 3.9 x 1026 watts.

Detailed explanation-2: -At Earth’s average distance from the Sun (about 150 million kilometers), the average intensity of solar energy reaching the top of the atmosphere directly facing the Sun is about 1, 360 watts per square meter, according to measurements made by the most recent NASA satellite missions.

Detailed explanation-3: -Above the earth’s atmosphere, solar radiation has an intensity of approximately 1380 watts per square meter (W/m2). This value is known as the Solar Constant. At our latitude, the value at the surface is approximately 1000 W/m2 on a clear day at solar noon in the summer months.

Detailed explanation-4: -In total approximately 70% of incoming radiation is absorbed by the atmosphere and the Earth’s surface while around 30% is reflected back to space and does not heat the surface.