1. Climates, Seasons, & Days
Motion of the Earth
Climates, Seasons, & Days

2. Earth’s Motion Earth has two major types of motion: Earth’s Rotation
Earth’s Revolution

3. Earth’s Rotation The spinning of the Earth on its axis
the axis is the imaginary line that runs vertically through the center of the Earth
rotates from East to West (counterclockwise)
Rotation of the Earth produces 2 main effects:
Speed causes the length of a day to be about 24 hours
Causes daily changes from day to night
At all times half of the Earth faces the sun, while the other half is in darkness
Areas within the Artic & Antarctic circles experience several weeks of daylight or darkness depending on the time of year

4. Earth Rotating

5. Earth’s Revolution The movement of Earth around the sun
Earth’s orbit is the slightly elliptical path that it travels around the sun
The sun is not in the center:
Around January 3rd earth is about 147million km away (closer)
Around July 4th earth is about 152 million km away (farther)
Revolution has 2 major effects:
The time it takes Earth to revolve around the sun once defines the length of a year
It takes 365 ¼ days to make one complete revolution
Every 4th year is leap year to make up for the extra day we gained
Earth revolves with a tilt of the axis
The revolution & tilt causes the changing seasons

6. Earth’s Revolution

7. How Earth Moves
In your group, demonstrate the difference between a rotation & a revolution.

8. Changing Seasons Earth’s axis is at an angle of 23.5° to its orbit
The axis always points in the SAME direction as the Earth orbits the Sun.
The Northern hemisphere points toward the sun half of the year & away from the sun for half the year
The tilt causes the Earth’s surface to receive different amounts of solar energy throughout the year.

9. Radiation from the Sun
The hemisphere that is tilted toward the sun receives more daylight hours and absorbs more radiation from the sun
The Sun’s radiation strikes the earth surface at a higher angle when the hemisphere is tilted toward the sun
The higher the angle the more radiation the earth absorbs creating warmer temperatures

10. Which month is receiving the most direct sunlight?
Seasons on Earth
Which month is receiving the most direct sunlight?
Least direct amount

11. Solstices
A solstice is the day when the Sun reaches its greatest distance north or south of the equator
The day Earth is tilted most toward the sun
June 21st is the summer solstice (northern hemisphere)
The most direct rays hit the Tropic of Cancer in the northern hemisphere causing the northern hemisphere to have warmer temperatures and more sunlight hours
Longest day of sunlight for the year
Daylight gets a little shorter each day after the solstice
Dec. 21st is the winter solstice (northern hemisphere)
The most direct rays hit the Tropic of Capricorn in the southern hemisphere causing the northern hemisphere to have cooler temperatures and less sunlight hours
Shortest day of sunlight for the year
Daylight hours get a little longer each day after the solstice

12. Equinox
An equinox is the day the Sun’s rays are directly above the Earth’s equator.
During this time equal amounts of sunlight are received all over the earth with the most direct rays hitting at 90° at the equator
March 21st is the spring equinox (northern hemisphere)
September 22nd is the autumn equinox (northern hemisphere)
Seasons are opposites in the Southern Hemisphere

13. Seasons on Earth
Earth has seasons because it is tilted as it revolves around the sun.

14. No matter what time of year, which areas of Earth receive the least direct sunlight?

15. Animation
revolution
Revolution
Extra Practice
Click on view

16. Climatic Zones The amount & angle of sunlight affects Climatic Zones
The latitude, distance north or south from the equator, affects the temperatures that commonly occur in that area.
The further from the equator the less direct the suns rays are
These yearly patterns cause weather patterns to occur in different regions of the earth that create climates.

17. World Climate Zones: Label in notes
Based on latitude, Earth’s surface can be divided into a tropical zone, two temperate zones, and two polar zones.

18. World Climate Zones
Polar Zone: Areas within the Arctic and Antarctic Circles, from N and S latitude to the poles
Characterized by a short, cool summer and long, bitterly cold winter.
Temperate Zone: between and north and south latitudes
 warm to hot summers and cool winters
Greatest temperature variation
Tropic Zone: degrees north latitude to south latitude
Warm year round with little seasonal variation

19. Air Temperature by Month

20. Biomes are large geographical areas with similar climates and ecosystems