1. APES Bell Ringer
**Turn in any missing work from Tuesday-Friday of last week!
Make sure to Include QUESTION and answer! 

2. Miller Chapter 6.1-6.2 Atmosphere and Weather
AP Environmental Science

3. Origin of Modern Atmosphere
Original atmosphere: Hydrogen and Helium
2nd atmosphere evolved from gases from molten Earth
H2O, CO2, SO2, CO, S2, Cl2, N2, H2, NH3, and CH4
Allowed formation of oceans and earliest life
Modern Atmosphere
evolved after Cyanobacteria started photosynthesizing
oxygen produced did not reach modern levels until about 400 million years ago

4. Continental Drift ~230 million years ago
1 giant landmass on Earth = Pangaea
As the continents moved toward their present-day locations the
Sea level dropped
Volcanoes erupted
Earth’s surface was pushed upward.
Effects on weather:
Drop in temperature and precipitation all over the Earth. These changes were gradual.

5. Extinction of the Dinosaurs?
Climate change = Extinction of the dinosaur?
Plants extinct Dinosaurs that ate these plants became extinct  Meat-eating dinosaurs that depended on plant-eating dinosaurs died
Other scientists believe that dinosaurs became extinct as the result of a giant asteroid striking the Earth 65 million years ago (many theories!)

6. Earth’s Atmosphere
Compared to the size of the Earth (104 km), the atmosphere is a thin shell (120 km).
If the Earth was an orange, the atmosphere would be the pesticides on its peel

7. Atmosphere Layers Exosphere Thermosphere (Ionosphere) Mesosphere
Stratosphere
Troposphere (closest to Earth)

8. Troposphere 8 to 14.5 kilometers high (5 to 9 miles) Most dense
Temperature decreases as altitude increases
Weather is found here!

9. Stratosphere Extends to 50 kilometers (31 miles) high
Dry and less dense
Temperatures increase as altitude increases
Due to the absorption of ultraviolet radiation
Ozone layer absorbs and scatters the solar ultraviolet radiation
99% of "air" is located in first two layers

10. The Atmosphere Mesosphere Thermosphere very little atmosphere
coldest layer
Thermosphere
ionosphere
aurora borealis
hottest layer
1000 C

11. Atmospheric pressure (millibars) Altitude (kilometers)
200
400
600
800
1,000
120 75
Temperature
110
Pressure 65
Thermosphere
100 90 55
Mesopause 80 45 70
Mesosphere
Altitude (kilometers) 60
Altitude (miles)
Stratopause 35 50
Heating via ozone 40 25
Stratosphere 30
Tropopause 15
Ozone “layer” 20
Heating from the earth 10
Troposphere 5
Pressure = 1,000
millibars at
ground level
(Sea
Level)
–80
–40 40 80
120
Temperature (˚C)

12. Atmosphere Composition
Nitrogen (N2, 78%)
Oxygen (O2, 21%)
Argon (Ar, 1%)
Variety of other very influential components are also present which include the Water (H2O, 0 - 7%), "greenhouse" gases or Ozone (O3, %), Carbon Dioxide (CO2, %),

13. What gas was originally not in the atmosphere?
A. Carbon dioxide
B. Water
C. Oxygen
D. Methane
Review Questions

14. The gas that composes 78% of the gases in the atmosphere is:
A. Oxygen
B. Nitrogen
C. Carbon Dioxide
D. Ozone
Review Questions

15. The atmosphere layer in which most of the weather occurs is the:
A. Troposphere
B. Stratosphere
C. Mesosphere
D. Thermosphere
E. Exosphere
Review Questions

16. Weather: A Brief Introduction
 result of the atmospheric conditions in a particular area over short periods of time, typically over hours or days
EX:
temperature, pressure, moisture content, precipitation, sunshine, cloud cover, and wind direction

17. CLIMATE
Average pattern of weather for a particular region
LONG TERM

18. OBJ 6.2

19. Climate 2 Main factors Temperature Precipitation Amount Distribution
Factors that affect temperature:
Latitude
Elevation
Closeness to large bodies of water
Climate

20. Closeness to Large Bodies of Water
Water moderates the temperature creating cooler summers and warmer winters

21. Elevation

22. Short Term Changes in Climate
Changes in ocean currents and global winds.
Ocean currents help transfer heat to the atmospheregenerates global windshelp move ocean currents.
Any major change in an ocean current can cause a change in climate
El Nino!!! (We will discuss this at the end! )