1. 17.1 Atmosphere Characteristics
Weather vs. Climate
17.1 Atmosphere Characteristics
Weather is constantly changing, and it refers to the state of the atmosphere at any given time and place.
Climate, however, is based on observations of weather that have been collected over many years. Climate helps describe a place or region.

2. Volume of Clean, Dry Air What is the most abundant gas in
our atmosphere?
What is the
second most
common gas?
Makes no sense without caption in book

3. 17.1 Atmosphere Characteristics
Composition of the Atmosphere
17.1 Atmosphere Characteristics
 Variable Components
Water vapor is the source of all clouds and precipitation
carbon dioxide, water vapor absorbs heat given off by Earth. It also absorbs some solar energy.
Ozone is a form of oxygen that combines three oxygen atoms into each molecule (O3).
ozone filters UV radiation in the stratosphere allowing life to exist as we know it,
In troposphere ozone causes smog

4. Primary Pollutants What is a primary pollutant?
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What is responsible for the majority of the
primary pollutants?

5. 17.1 Atmosphere Characteristics
Height and Structure of the Atmosphere
17.1 Atmosphere Characteristics
 Pressure Changes affect temprature
Atmospheric pressure is simply the weight of the air above.
An increase in altitude = decrease in pressure
Decreases in pressure =decrease in temperature

6. Atmospheric Pressure vs. Altitude
Why does the
atmosphere
thin (become
less dense)
with altitude?
What affect
does this have
on temperature?
Makes no sense without caption in book

7. 17.1 Atmosphere Characteristics
Height and Structure of the Atmosphere
17.1 Atmosphere Characteristics
 Temperature Changes
Why is the
Atmosphere
Divided into
Layers?
• The atmosphere is divided vertically into four layers based on temperature change.
• troposphere bottom layer of the atmosphere where temperature decreases with an increase in altitude. Decreased pressure = decreased temp
• stratosphere layer on top of troposphere temperature gradual increase because of O3

8. Snowy Mountaintops Contrast with Warmer Snow-Free Lowlands
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9. 17.1 Atmosphere Characteristics
Height and Structure of the Atmosphere
17.1 Atmosphere Characteristics
 Temperature Changes
• mesosphere the layer above the stratosphere and is characterized by decreasing temperatures with height, contains no O3
• thermosphere the layer above the mesosphere and is characterized by increasing temperatures due to the absorption of very short-wave solar energy, atoms absorb max energy

10. Thermal Structure of the Atmosphere
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11. 17.1 Atmosphere Characteristics
Earth-Sun Relationships
17.1 Atmosphere Characteristics
 Earth’s Motions
• rotation = day and night; revolution = seasons
 Why do we have seasons?
• Seasonal changes occur because of earths revolution around the sun and Earth’s axis is tilted to 23.5O

12. Tilt of Earth’s Axis
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13. 17.1 Atmosphere Characteristics
Earth-Sun Relationships
17.1 Atmosphere Characteristics
 Solstices and Equinoxes
• summer solstice occurs on June 21 or 22 in the Northern Hemisphere and is the “official” first day of summer.
• winter solstice occurs on December 21 or 22 in the Northern Hemisphere and is the “official” first day of winter.
During our winter solstice what season is it in Australia?

14. 17.1 Atmosphere Characteristics
Earth-Sun Relationships
17.1 Atmosphere Characteristics
 Solstices and Equinoxes
• autumnal equinox (Fall) occurs on September 22 or 23 in the Northern Hemisphere.
• spring equinox (vernal) occurs on March 21 or 22 in the Northern Hemisphere.

15. 17.1 Atmosphere Characteristics
How is the length of daylight compared to the length of darkness determined?
17.1 Atmosphere Characteristics
is determined by Earth’s position in orbit. Think of the Arctic and Antarctic circle.

16. Solstices and Equinoxes
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17. 17.2 Heating the Atmosphere
Energy Transfer as Heat
17.2 Heating the Atmosphere
 Heat energy transferred from one object to another because of a difference in the objects’ temperature.
 Temperature a measure of the average kinetic energy a substance, hot more kinetic energy, cold less kinetic energy

18. 17.2 Heating the Atmosphere
What are the three mechanisms of energy transfer as heat?
1. Conduction transfer of heat through solids
What are insulators? What are conductors?
2. Convection transfer of heat through fluids

19. 17.2 Heating the Atmosphere
3. Radiation transfer of energy (heat) through space by electromagnetic waves, can travel through the vacuum of space others can not
How does wavelength
Relate to radiant
temperature?
6000Co=11000Fo

20. Energy Transfer as Heat
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21. 17.2 Heating the Atmosphere
Electromagnetic Waves everything that has heat emits these waves. Energy emitted by the sun are part of the electromagnetic spectrum
Are good absorbers also good emitters of radiant energy?

22. Visible Light Consists of an Array of Colors
Why can you see the spectrum of electromagnetic waves?
Makes no sense without caption in book

23. Solar Radiation What Happens to Solar Radiation?
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24. 17.2 Heating the Atmosphere
What Happens to Solar Radiation?
17.2 Heating the Atmosphere
• Reflection when light bounces off an object, with same intensity as incident radiation.
• Scattering when light bounces off an object producing a larger number of weaker rays that travel in different directions.

25. 17.2 Heating the Atmosphere
 Absorption
• 50 percent of the solar energy that strikes the top of the atmosphere reaches Earth’s surface and is absorbed.
• greenhouse effect heating of Earth’s surface and atmosphere from solar radiation being absorbed and emitted by the atmosphere, two main gasses involved water vapor and carbon dioxide.

26. Global warming (climate change): the Green House Effect sped up by human activity
What is the Green House Effect? What are the main gases that cause the effect?
What are the main greenhouse gases in troposphere causing global warming?

27. What are the 6 things causing Temperatures to vary?
17.3 Temperature Controls
1. Land (low specific heat capacity) heats more rapidly and to higher temperatures, also cools more rapidly and to lower temperatures. Deserts cold at night hot during day
2. Water (high specific heat capacity) heats up slowly and cools down slowly

28. Mean Monthly Temperatures for Vancouver and Winnipeg
Which is close
to the ocean?
What is the effect?
Which is furthest
from the ocean?
Makes no sense without caption in book

29. 17.3 Temperature Controls 3. geographic setting
How does geographic position
influence these two cities?

30. 17.3 Temperature Controls 4. altitude How does altitude
influence temperature?

31. 17.3 Temperature Controls
5. Cloud cover high albedo therefore reflect back to space a significant portion of suns energy
• Albedo is the fraction of total radiation that is reflected by any surface.
How does cloud albedo affect these two pictures?

32. 17.3 Temperature Controls World Distribution of Temperature
 Isotherms lines on a weather map that connect points of the same temperature
What do you notice
about the isotherms
in the north
compared to the
south?