1. The Sun

3. Energy from the Sun (Fusion)
Energy from the sun is called solar energy. Solar energy is the solar radiation that reaches the earth.
This Energy is created by Nuclear Fusion that takes place at the sun’s core.
Each second the sun converts about 600,000,000 tons of Hydrogen nuclei into Helium nuclei.
When the H converts to He, some neutrons are lost and released as ENERGY that gives off HEAT and LIGHT into our solar system.

4. Our Sun
Corona: outer layer that creates the ‘solar wind’ which can go 800 km/s
Temp over 1 million degrees Celsius
Photosphere: surface layer responsible for most of visible light about 6,000 degrees Celsius
SunFusion

5. Our Sun
Sunspots: cooler areas of surface that appear darker (study of sunspots lead to discovery that the sun rotates)
Prominences: ionized gas clouds that are still trapped by electromagnetic field
Solar Flares: explosive out burts (1 hour)
UV, radio, and x-ray radiation
Takes about 1 day to reach Earth
photo

6. Roles the Sun Plays here on Earth:
It is a major source of energy.
It helps plants to grow.
It is part of the water cycle.
It dictates the seasons.
It controls the weather.

7. Differential Heating
Land and water surfaces absorb heat at different rates
Water has a higher capacity for storing heat than land
This means the ground will heat up much quicker than water from the same amount of sun radiation
Water- heats and cools slowly
Land- heats and cools quickly

8. Photosynthesis
Solar energy is transferred to chemical energy through photosynthesis
Occurs in plants, algae, and some bacteria
Convert carbon dioxide and water using energy from the sun to sugar (chemical energy)

9. The Sun’s Energy Electromagnetic Radiation: heat energy from the sun
Radiation is emitted throughout the electromagnetic spectrum at the speed of light, whether or not we can see it. The shorter the wavelength, the higher the energy.
Solar radiation is composed of:
40% at wavelengths of infrared (IR) or longer
50% at visible wavelengths
10% at wavelengths of ultraviolet (UV) or shorter (think: skin penetration)

10. The Sun’s Energy
The Sun also emits other types of radiation such as X-rays and cosmic rays
These rays are absorbed by Earth’s atmosphere before they reach Earth

11. How bright? about 4 x 1026 Watt light bulb
Releases all waves of light

12. How Sun’s Energy is Transferred
Conduction occurs when energy is transferred from earth’s surface air to atmospheric air.
Convection occurs as pockets of air near earth’s surface are heated, become less dense, rise, cool, and sink. Then heated and cycle over again.
How Sun’s Energy is Transferred
Solar radiation is radiant energy emitted by the sun, particularly electromagnetic energy.

13. Electromagnetic radiation (spectrum) Gamma rays - fastest X-rays
Light
Electromagnetic radiation (spectrum)
Gamma rays - fastest
X-rays
UV rays
Visible spectrum (ROYGBIV)
Infrared waves
Radio waves – slowest
Electromagnetic Spectrum: The arrangement of these waves according to their wavelengths and frequencies

14. Types of Radiation
The types of radiation are determined by the length of their waves
Short wave lengths (shorter than light waves):
Ultraviolet rays
X rays
Gamma rays

15. Types of Radiation Longer Wavelengths include: Infrared Radio waves
**All of these types of radiation are called electromagnetic waves

16. Energy and Earth’s Atmosphere
1st the upper atmosphere (oxygen and nitrogen) absorbs the short wavelengths of x rays, gamma rays and ultraviolet rays
Occurs in thermosphere and mesosphere
2nd in the stratosphere ultraviolet rays are absorbed and react with oxygen to form ozone
3rd some ultraviolet radiation reaches Earth and can cause sunburn

17. Energy and Earth
Most solar rays that reach earth have a longer wavelength (visible and infrared rays)
Infrared radiation are absorbed by carbon dioxide, water vapor etc. in the troposphere
We receive most visible light rays

18. Totals of Solar Energy ~ 20 % of energy is absorbed by the atmosphere
~30% is scattered back to space
~50% is absorbed by Earth’s surface
Depends on what type of surface the ray hits (water, desert, grass, snow etc.)

19. Solar Winds The sun also creates solar winds.
They are a continuous stream of electrically charged particles that are given off by a magnetic field around the sun.
               
It takes a solar wind about 4.5 days to reach Earth.

20. So why don’t we burn up?
The earth has a magnetic field that protects us by deflecting the solar winds.
You can even see the interaction between our magnetic field and the solar winds when auroras are created. The most famous are in the northern hemisphere and called the aurora borealis. Auroras also appear on other planets with magnetic fields.

23. Sun Diagram Draw the diagram of the Sun
Label, Color, and describe each part