1. Reasons for the Seasons

2. The four seasons on Earth include:
What are the seasons?
Seasons are the four distinct times of the year when there is a change in temperature on Earth.
The four seasons on Earth include:
Winter Solstice
Spring (Vernal) Equinox
Summer Solstice
Fall (Autumnal) Equinox

3. What causes seasons?
Seasons are caused by the tilt of the Earth’s axis as it revolves around the Sun.
23.5°

4. Summer in the Northern Hemisphere
When it is summer in the Northern Hemisphere, it is winter in the Southern Hemisphere. This is because the Northern Hemisphere is receiving more direct sunlight.

5. Summer in the Northern Hemisphere
The Northern Hemisphere is receiving more direct sunlight than the Southern Hemisphere.

6. Winter in the Northern Hemisphere
The Southern Hemisphere is receiving more direct sunlight than the Northern Hemisphere.

7. Summer and Winter Solstice
The Northern Hemisphere receives more direct sunlight – because of this temperatures are warmer.
The Northern Hemisphere has longer days and the Southern Hemisphere has shorter days.
Winter
The Northern Hemisphere receives less direct sunlight – because of this temperatures are cooler.
The Northern Hemisphere has shorter days and the Southern Hemisphere has longer days.

9. Fall/Autumnal and Spring Equinox
Both hemispheres receive the same amount of direct sunlight.
Both hemispheres have equal day and night (12 hours of day, 12 hours of night).
Neither hemisphere is tilted toward the sun at this time.

10. What happens during Spring and Fall?
During the equinoxes, spring and fall, both the Northern and Southern Hemispheres are receiving the same amount of direct sunlight. Neither hemisphere is tilted toward the Sun, so temperatures aren’t extremely different. Neither hemisphere or very warm or cold.

11. How can the length of day affect temperatures on Earth?
Think, Pair, Share
How can the length of day affect temperatures on Earth?

12. Longer days cause overall temperatures to be warmer
Longer days cause overall temperatures to be warmer. This is because the Sun is out longer, and there is more radiation from the Sun during this time. Shorter days causes overall temperatures to be cooler. This is because the Sun isn’t out as long, and there is less radiation from the Sun during this time.

13. Quiz Time
Please put away your notes to see how much you remember from the presentation.

14. 1. Why do we have seasons on Earth?
The distance between the Earth and Sun.
The tilt of the Earth’s axis as it revolves around the Sun.

15. 2. When it is summer in the Northern Hemisphere, which of the following is true?
The Northern Hemisphere receives less direct sunlight.
The Northern Hemisphere has shorter days.
The Northern Hemisphere has colder temperatures.
The Northern Hemisphere receives more direct sunlight.

16. Position A Position B Position C Position D
3. Which of the following positions would Earth be in if it were winter in the Southern Hemisphere?
Position A
Position B
Position C
Position D

17. Position A Position B Position C Position D
4. Which of the following positions would Earth be in if it were winter in the Northern Hemisphere?
Position A
Position B
Position C
Position D

18. 5. Which of the following contributes to warmer temperatures on Earth?
More direct sunlight
Longer days
All of the above

19. 6. Which two seasons are solstices?
Spring and Summer
Summer and Fall
Winter and Summer
Fall and Winter

20. 7. Which of the following is true about an equinox?
Both hemispheres receive the same amount of direct sunlight.
Both hemispheres have equal day and night.
Equinoxes happen during the fall and spring.
All of the above.