solar energy on earth


Of the solar energy that reaches the outer atmosphere, ultraviolet (UV) wavelengths have the greatest energy. Only about 7% of solar radiation is in the UV wavelengths. The three types are: UVC: the highest energy ultraviolet, does not reach the planets surface at all. UVB: the second highest energy, is also mostly stopped in the atmosphere. UVA: the lowest energy, travels through the atmosphere to the ground.

energy from the sun

Most of the energy that reaches the Earths surface comes from the Sun (Figure 1.1). About 44% of solar radiation is in the visible light wavelengths, but the Sun also emits infrared, ultraviolet, and other wavelengths.


The remaining solar radiation is the longest wavelength, infrared. Most objects radiate infrared energy, which we feel as heat. Some of the wavelengths of solar radiation traveling through the atmosphere may be lost because they are absorbed by various gases (Figure 1.2). Ozone completely removes UVC, most UVB, and some UVA from incoming sunlight. O2 , CO2 , and H2 O also filter out some wavelengths. An image of the Sun taken by the SOHO spacecraft. The sensor is picking up only the 17.1 nm wavelength, in the ultraviolet wavelengths. Atmospheric gases filter some wave- lengths of incoming solar energy. Yel- low shows the energy that reaches the top of the atmosphere. Red shows the wavelengths that reach sea level. Ozone filters out the shortest wavelength UV and oxygen filters out most infrared. Click image to the left or use the URL below. URL:



instructional diagrams

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how is the suns energy important to earth?

a) the sun heats the planet

b) it drives the weather

c) it helps plants conduct photosynthesis

-->  d) all of the above

sensors can detect wavelengths of energy we cant see and convert them to visible light.

-->  a) true

b) false

this is the only type of energy humans can see.

a) x-rays

b) microwaves

c) infrared

-->  d) visible

with an infrared camera, a living creature

a) is hottest at the top of the head.

b) is hottest around the face.

-->  c) is hottest around the eyes, mouth and ears.

d) is the same temperature all around.

a shorter wavelength means the wave has less energy.

a) true

-->  b) false

stratospheric ozone filters out incoming

-->  a) uvc completely, most uvb, and some uva.

b) irc completely, most irb, and some ira.

c) all ultraviolet.

d) electromagnetic radiation.

the highest energy ultraviolet is __ and the lowest energy ultraviolet is _.

a) uva; uvc

-->  b) uvc; uva

c) uva; uvb

d) uvb; uvc

the only wavelength of energy that are filtered by the atmosphere are uv waves.

a) true

-->  b) false

oxygen in the atmosphere filters out

a) red waves of visible light

b) the shortest wavelength ultraviolet.

-->  c) infrared.

d) the longest wavelength ultraviolet.

diagram questions

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