1. The Sun and it’s Effects
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2. The sun’s size average sized yellow star largest in our solar system
Diameter=1.4 million km
10 x larger than Jupiter
109x larger than earth

3. Sun’s make up -about 70% hydrogen and about 28% helium
-Remaining 2%- Carbon and Oxygen
-The sun makes up 99% of all the mass in our solar system

4. Structure of the Sun http://www.spacetelescope.org/videos/astro_ac/
Layered
Core- central region- made up of plasma
fusion reactions occur- hydrogen atoms come together to form helium atoms
high temp- above 15 million degrees celsius
high pressure
Reactions release energy in the form of electromagnetic radiation

5. Structure of the Sun Radiative zone- layer surrounding the core
Temp approx 8 million degrees celsius (can range from 2-8 million)
Absorbs thermal energy produced in the core and transfers it as electromagnetic radiation
Emits electromagnetic radiation into the outer layer called the convection zone

6. Structure of the sun Convection zone- outermost layer of the sun
Temp. around 2 million degrees celsius
Has rising and falling currents of gas called convection cells
Currents carry energy into the sun’s atmosphere (first layer- photosphere)

8. Sun’s Atmosphere
3 layers
Photosphere
Chromosphere
Corona

9. Sun’s Atmosphere Photosphere innermost layer thinnest layer
Temp. around 6000 degrees C
Layer that we see- emits visible light

10. Sun’s Atmosphere Chromosphere- layer above the photosphere
Temp- approx. 20,000 degrees C
produces most of sun’s UV radiation
Thicker than photosphere

11. Sun’s Atmosphere Corona- top layer
Temp. 1 million to 3 million degrees celsius
Thickest layer
Low density
Emits less radiation than other layers

12. Other Features
Granules are the tops of convection cells and give the photosphere a grainy appearance.
Sunspots- dark cool areas of the photosphere connected by magnetic fields called prominences

13. Drawing Time! (left page)
Draw a picture of the sun and it’s layers and label it
Include the temperature of each layer
Include a description of each layer
Add the layers of the sun’s atmosphere and label it
Include a brief description of each
Make sure your layers are the appropriate thickness
Add sunspots and show convection currents in the appropriate layers of the sun or atmosphere
Color your drawing to clearly show the different layers

14. Sunspots Temps up to 2000K cooler than the surrounding areas
Bright but not as bright as their surroundings which is why they appear dark to us
Not permanent they tend to appear and disappear
Sunspot activity seems to cycle every 11.2 years
Scientists determined that the equator of the sun rotates faster than the poles by observing sunspots

15. The Magnetic Sun
-Images of the Sun reveal loops of hot ionized gas (plasma) above the locations of Sunspots.
-The shapes of these loops are just like the loops of force between two opposite poles of a magnetic field.
**The plasma acts just like iron filings and traces out the magnetic field on the Sun.

16. Movement of Plasma The plasma is trapped within the magnetic fields.
It can flow lengthwise along the loops, but it cannot flow sideways across the loops.

17. Suns magnetic fields
The magnetic fields in sunspots do not allow plasma from the surrounding region to enter which results in a drop in plasma pressure and cooler temps.
***The magnetic field strength in a Sunspot is an average of 1,000 times stronger than the magnetic field at Earth’s surface.

18. The solar cycle
Because the equator of the sun moves faster than the poles, the sun’s magnetic field becomes more and more twisted and complex. It finally breaks and flips every 11 years.
As the magnetic field
becomes more twisted
small loops of it push
through the surface
creating sunspots and
coronal loops

19. Solar Flares
Solar flares occur when gases emitted by sunspots reach an excited state (moving as fast as the speed of light) causing them to give of ultraviolet and x-ray radiation
-They contain so much energy that the sun’s magnetic fields cannot hold them and they are released into space

20. Solar Flares Continued
-Large solar flares can emit large bubbles of plasma called coronal mass ejections (CME’s)
-Coronal mass ejections can change the solar wind and create colorful ribbons of light called auroras
-Strong CME’s can create solar storms that can even affect the magnetic poles of earth

21. Read the article and answer the questions
1. In your own words explain why the sky is blue.
(3-5 complete sentences)
2. Explain why the sunsets are often red.

22. Sun= Energy The sun is earth’s main energy source
Half of sun’s energy is absorbed by earth’s surface
Other half
absorbed by atmosphere
reflected back into space by earth or clouds

23. Why is the sky blue?
Scattering- dust and gas in earth’s atmosphere deflect radiation from the sun
- atmosphere scatters shorter wavelengths of light in the blue range more strongly than longer wavelengths.

24. Earth’s Atmosphere -Made mostly of nitrogen (78%) -Oxygen (21%)
-Other gases (1%)
Oxygen and Nitrogen absorb very little sunlight

25. Absorbing Sunlight
Surface of earth and oceans absorb energy from sun and warm up.
Air above surfaces warms and rises
Cool air sinks down
Energy that is radiated from earth’s surface is in the form of infrared radiation

27. Albedo
Reflectivity- measured as a percentage of radiation that is reflected
Earth’s albedo including it’s atmosphere is .3
30% of energy from the sun is reflected
Most of the energy is reflected by clouds and air
4% reflected by earth’s surface
Different surfaces have different albedos

28. Benefits of Solar Radiation
Required for photosynthesis- process in which plants make their own food
Animals feed on plants or one another
Creates weather
Drives movement of oceans
Powers water cycle
Provides earth’s energy- solar power, wind power, formation of fossil fuels

29. Harmful Solar Radiation
UV rays can cause tissue damage to both humans and plants
UV rays are increasing due to depletion of ozone layer
Ozone- 3 oxygen atoms combined
CFC’s or chlorofluorocarbons are pollutants released from different chemicals on earth
CFC’s bond with oxygen from O3 breaking apart the ozone molecules
Less ozone in the ozone layer=more UV rays reaching earth

32. ABC’s left page assignment
Using your notes on the sun you must come up with a term for each letter of the alphabet and give a definition or explanation of how it relates to class. You are allowed 3 skips.
Example:
A- Albedo- another term for reflectivity, earth’s albedo is 30% meaning 30% of energy from the sun is reflected