2. Size of Earth’s Atmosphere
Air
invisible, odorless, colorless and tasteless
extends out 10,000 km (6000 miles)
98% is within 26km (16 miles) of sea level
held by gravitational force
makes life possible (oxygen for animals, carbon dioxide for plants)
maintains water supply
insulates us against extreme temperatures
shields us from ultraviolet radiation

3. Composition of the Atmosphere
Atmospheric Gases

4. Composition of the Atmosphere
Gases
Nitrogen 78 %
Oxygen 21 %
Argon 0.9 %
Neon
Helium
Krypton
Hydrogen
Important variable
amount gases
Water vapor (H2O)
Carbon dioxide (CO2)
Carbon monoxide (CO)
Methane (CH4)
Ozone (O3)
Sulfur dioxide (SO2)
Nitrogen dioxide (NO2) }
Total < 0.09 %

5. Composition of the Atmosphere
Atmospheric Particulates

6. Composition of the Atmosphere
More particulates: smoke from wild fires, meteorite debris, pollen grains, oceanic salt spray, volcanic ash, industrial emissions, dust storms, etc.
Human-induced
Natural

7. Vertical Structure of the Atmosphere
Atmospheric Pressure

8. Thermal Layers of the Atmosphere
Meanings
Exosphere = outer
Thermosphere = heat
Mesosphere = middle
Stratosphere = layers
Troposphere = mixing
Each warm zone has a specific source of heat:
Thermosphere - atoms and molecules absorbing UV and being split
Stratosphere - ozone layer absorbs UV
Visible light - absorbed by surface and lowest layer of troposphere

9. Troposphere Troposphere: Layer where weather occurs
Extends 8-18 km (5-11 mi) outwards from the surface
Deeper in summer and at tropics

10. Stratosphere - where the Ozone Layer is found

11. Atmospheric Composition
Heterosphere: beyond 80 km (50 mi) the gases are layered according to molecular masses
heterogenous composition
Homosphere: throughout lowest 80 km (50 mi) the gases are distributed uniformly
homogenous composition

12. Division of the Atmosphere
Deep layer of electrically charged molecules and atoms (ions) important in long-distance communications (radio waves) and for aurora displays
Division of the Atmosphere
Based on chemical composition
Based on temperature (thermal layers)
Based on function
Homosphere (0-50 miles)
Heterosphere (beyond 50 miles)
Troposphere: to 11 miles Stratosphere: miles
Mesophere:30-50 miles
Thermosphere: 50 miles out, turning into exosphere
Ozonosphere (9-30 miles)
Ionosphere ( miles)
Ozone absorbs UV radiation, protecting us from the sun

13. Natural Ozone Formation
Human-Induced Atmospheric Change
Natural Ozone Formation

14. Ozone Destruction by CFCs
Human-Induced Atmospheric Change
Ozone Destruction by CFCs
Ozone hole over Antarctica

15. Human-Induced Atmospheric Change
Consequences:
the “hole” in the ozone layer (UV-B, UV-C)
acid rain and smog (airborne pollution)
Ventura County’s worst offenders = particulate matter and ozone pollution
Associated health problems:
respiratory diseases
skin cancers
Depletion of Ozone Layer video

16. Ozone Loss over the Poles
CFCs originate in Northern Hemisphere
redirected by winds (toward poles)
stratosphere
high, thin cloud cover
cold temperatures
Chlorine atoms freed at high rates (poles)
“hole” over Antarctica larger than Arctic
Mid-lats also experiencing ozone thinning
UV passes to Earth’s surface

17. Weather/climate and the troposphere
Weather and Climate
Definitions
Weather: short-term atmospheric conditions that exist in a specific location during a specific time
Climate: long-term atmospheric conditions that exist in a location, localized or broad, during a prolonged period of time
Weather/climate and the troposphere

18. Elements of Weather and Climate

19. Controls of Weather and Climate

20. Latitude

21. General Circulation of the Atmosphere

22. General Circulation of the Oceans

23. Elevation/Altitude

24. Topographic Barriers

25. Storms

26. Coriolis Effect
Coriolis effect: the apparent horizontal deflection of free-moving objects in response to the rotation of the Earth
Northern Hemisphere: to the right
Southern Hemisphere: to the left
deflection is strongest at the poles
deflection is zero at the equator
the faster the object, the more deflection
direction of movement affected, not speed
Coriolis Effect video

27. Coriolis Effect

28. Homework Have syllabus & textbook? ADD SLIPS – list/sign.
2. Read Chapter 3.
3. HW #1
Define the UV Index.
Why is it important?
Summarize, image, or alternative.
Note: All homework due… the
next week (or) before the midterm.
Sub-tropical storm over Ventura County