1. 17.1 – Atmospheric Structure and Temperature – Part II

2. Do Now
Why do seasonal changes occur?

3. Do Now Why do seasonal changes occur?
Because Earth’s position relative to the sun continuously changes as it travels along its orbit.

4. Key Words
Rotation
Revolution
Orbit

5. Vocab Words Summer Solstice Winter Solstice Autumnal Equinox
Spring Equinox

6. Earth-Sun Relationships
Nearly all of the energy that drives Earth's variable weather and climate comes from the sun.
Solar energy is not distributed evenly over Earth's surface.
The amount of energy received varies with latitude, time of day, and season of year.
It is the unequal heating of Earth that creates winds and drives the ocean's currents.
This causes weather

8. Earth’s Motions Rotation
The spinning of Earth about its axis. 24 hours
Revolution
Movement of Earth in its orbit around the sun. 1 year

10. Solstices
The summer solstice is the solstice that occurs on June 21 or 22 in the Northern Hemisphere and is the “official” first day of summer.
The winter solstice is the solstice that occurs on December 21 or 22 in the Northern Hemisphere and is the “official” first day of winter.

11. Equinoxes
The autumnal equinox is the equinox that occurs on September 22 or 23 in the Northern Hemisphere.
The spring equinox is the equinox that occurs on March 21 or 22 in the Northern Hemisphere.

13. Length of Daylight
The length of daylight compared to the length of darkness also is determined by Earth’s position in orbit.

14. Group Activity
Copy and label the picture on page 482.