Why does sunlight not hit Earth's surface everywhere with the same intensity?
- CarolOklaLv 78 months agoFavourite answer
Because sunlight has maximum power when it strikes a surface at a 90° angle. The intensity of sunlight hitting Earth surface can vary widely because of clouds, sand, dirt, ash and pollutants in the air. Its is the POWER that is important.
Sunlight can strike the Earth's surface at a 90° angle only between the latitudes of +23.5 ° N, the Tropic of Cancer, and -23.5° S, the Tropic of Capricorn. Any latitude north or south of that, sunlight strikes the surface at an angle , so sunlight has less POWER. This is WHY satellite dishes and some telescopes are tilted at an angle.
- Andrew SmithLv 78 months ago
There is more than one reason for this.
Although you have seen the effects of angle the effects of air are even more pronounced.
I live in a sunny climate. So no clouds and no appreciable dust. Facing the panel so that it is 90 degrees to the sun I get a figure of 250 W at midday.
At 4pm even though I face the panel at the sun so that it is also at 90 degees the output has halved.
By 6 pm it has fallen to only 15% of its midday value.
The ONLY difference is the amount of air that the rays of the sun must pass through from when they enter the atmosphere to when they reach the panels.
This same effect applies to the midday sun at various latitudes.
At a latitude of 45 degrees even the midday sun must pass through 1.4 times as much air as at the equator.
And there is also a greater amount of dust and cloud in that atmosphere so the loss is typically worse than this.
- 8 months ago
First of all what comes from the SUN is not light but gravity, bubbles of neutral energy, which upon hitting our magnetic field and upper levels of the atmosphere join with bubbles of similar size and produce polarized energy, namely light and heat. If you went into space beyond our atmosphere you would see sun as very dim almost invisible in the visible spectrum.
- LoganLv 58 months ago
Because the earth is not flat. The point on the sphere that is facing the sun is receiving the highest intensity. Compare 1 sq ft at the point facing the sun and another sq ft 45deg or 3100 miles away from the first point The second point is tilted 45 degrees from the direct rays and receives only 71%(sin 45 ) of the energy.
- What do you think of the answers? You can sign in to give your opinion on the answer.
- G. WhilikersLv 78 months ago
At any given time, half the Earth's surface is on the side opposite the Sun, and receives no light at all.
- Anonymous8 months ago
Hint, why is there day and night?