1. ATMOSPHERE

2. Composition of the Atmosphere
The atmosphere is comprised of a variety of gases:
Major Constituents (99%):
Nitrogen (N): 78%
Oxygen (O2): 21%
Trace Constituents:
Other: 1%

3. Recycling of Atmospheric Materials

4. Movement of Heat Energy
Radiation: the transfer of energy through space in the form electromagnetic waves.
Convection: the transfer of heat energy in a liquid or gas through the motion caused by differences in density.
Conduction: the transfer of heat energy through
collisions of the atoms or molecules of a substance.

5. Heat and Temperature
Temperature: is a measure of the average kinetic energy of atoms or molecules in the substance.
Heat: the total kinetic energy of all of the particles of the substance.

7. Troposphere: The lowest region of the atmosphere (0 to 15 km altitude)
Where weather occurs
It contains 99% of the water vapor and 75% of the atmospheric gases
Temperature decreases with altitude.
Top of the troposphere is known as the tropopause

8. Stratosphere 15 to 50 km altitude
Heating occurs because ozone (O3) absorbs ultraviolet radiation from the Sun.
Temperature increases with altitude due to ozone absorbing ultraviolet radiation.
Top of the stratosphere is known as the stratopause

9. Mesosphere 50 to 90 km altitude Temperature decreases with altitude
The lowest temperatures in the entire atmosphere are found in this layer
Top of the mesosphere is known as the mesopause

10. Thermosphere 90 to 500 km altitude
Temperature increases with altitude above 90 km, and is constant above 200 km.
heating is due to absorption of solar radiation.
The highest temperatures in the atmosphere found in this layer

11. Ionosphere:
Occurs within the mesosphere and thermosphere between 90 and 500 km.
Layer of electrically charged particles
Effected by solar events
Auroras (Northern and Southern lights).

12. Exosphere: The exosphere is the outer most layer of the atmosphere.
The temperature in the exosphere goes up with altitude.
Satellites orbit Earth in the exosphere

13. Insolation and the Atmosphere
Insolation: incoming solar radiation.
some solar radiation is absorbed by gases in the atmosphere
some solar radiation reaches the Earth’s surface
some solar radiation is scattered in the atmosphere and is returned to space

15. Heat Budget of Earth and the Atmosphere
50% of solar radiation reaches the Earth’s surface
Small % of insolation is absorbed by the atmosphere
Energy is transferred by
radiation
conduction
evaporation
condensation of water
energy transfer is the major cause of Earth’s weather

16. Heat Budget of Earth and the Atmosphere
carbon dioxide and water vapor
absorbs most of the infrared radiation
prevents energy from radiating back into space creating the Greenhouse effect.
Without the Greenhouse Effect,
Most of the heat energy would be lost to space
Earth’s average temperature would be about 33oC cooler.
increased levels of carbon dioxide (CO2) in the atmosphere
Could cause the Earth’s heat budget be out of balance
Causes Global Warming.

17. Temperature variations due to Insolation
intensity of insolation varies due to:
time of day
latitude
time of year.
Color affects how much insolation is absorbed and how the absorbed energy affects the temperature

18. Intensity of Insolation
Intensity of insolation is depended on the angle at which the sun’s rays strike Earth’s surface.
the sun at 90o, Earth receives the maximum amount of energy.
Occurs at noon, Earth’s surface heats up quickly
As the angle of insolation decreases the amount of energy received decreases
Warmest temperatures occur several hours after noon, lower atmosphere receives more energy from the ground than it loses
Coolest temperatures occur right before dawn, ground and atmosphere have lost most of its heat

19. Intensity of Insolation
intensity of insolation is affected by the latitude.
closer to the equator the sun’s rays are almost vertical, climate is hotter
Moving either north or south of the equator the angle of insolation decreases, the energy spreads out over a larger area, climate is colder

20. Intensity of Insolation
At mid-latitudes
sun ray’s nearly vertical in the summer; summers are hot.
winter the angle of insolation is at its lowest; winters are cold.
Northern Hemisphere
greatest angle of insolation occurs around Jun 21, thus July is the warmest month of the year.
lowest angle of insolation occurs around December 21, thus January is the coldest month.
The southern hemisphere is the reverse

21. The affect of the insolation on sea-level temperatures in January and July.
What changes do you notice?

22. Human Impact on the Atmosphere

23. Acid Rain Forms due to pollutants Acidity is measured by pH.
sulfur dioxide and nitrogen dioxide react with water vapor
Acidity is measured by pH.
The lower the pH the more acidic the rain.

24. Smog
Temperature inversion: when the temperature at the Earth’s surface is cooler than the air above it, convection does not occur

25. Ozone Depletion
Hole in Ozone layer due to pollution of chloroflurocarbons (CFCs).
Greatly reduced due to the elimination of CFCs.
Thin Ozone/Hole forms each spring over Antarctica.
Thinning Ozone/hole allows for exposure to ultraviolent radiation which is dangerous to living things.