1. The Atmosphere: Structure and Temperature

2. How Does Weather differ from Climate?
Weather : constantly changing and it refers to the state of the atmosphere at any given time and place
Climate – is based on observations of weather that have been collected over many years

3. Measurable Properties of Weather and Climate
Air temperature
Humidity
Type/Amount of Precipitation
Air Pressure
Speed/Direction of Wind

4. Composition of the Atmosphere
Major Components:
Air – a mixture of different gases and particles
Nitrogen and Oxygen makeup 99%
1 % is argon
Carbon dioxide is present in small amounts but is an active absorber of energy so plays a role in heating.

5. Variable Components: Water Vapor
Water vapor - source of all clouds and precipitation.
Absorbs heat and some solar energy

6. Dust Particles
Movements of the atmosphere allow solid and liquid particles to be suspended within it
Large Particles are too heavy to stay in the air for too long
Microscopic remain suspended for longer
Examples: smoke, pollen

7. Ozone Not distributed evenly
Absorbs Potential harmful UV radiation by the sun
Without it our habitat would be uninhabitable

8. Human Influences and Primary Pollutants
Primary Pollution: emitted directly from identifiable sources
Transportation counts for half
Secondary Pollutions: not emitted directly into air (agriculture)
Can be caused by reactions

9. Primary Pollutants and Sources
Carbon monoxides
Nitrogen oxides
Volatile Organics
Sulfur oxides
Particulate matter
Sources
Transportation
Stationary Source Fuel Combustion
Industrial Processes
Solid Waste

10. Pressure and Temperature Changes
Key Point: The atmosphere rapidly thins as you travel away from Earth until there are too few gas molecules to detect.
Pressure Changes
Atmospheric pressure is the weight of the air above.
As you go up in altitude (or travel away from Earth) pressure decreases

11. Layers of the Atmosphere
The Troposphere - the bottom layer
Temperature decreases with an increase in altitude.
Where weather occurs
Tropopause: boundary of the troposphere
The Stratosphere
Above the troposphere
Temperature remains constant, then gradually starts to increase
Contains the ozone layer
Stratopause: boundary of the stratosphere

12. The Thermosphere: Upper layer
The Mesosphere
Temperature decreases with height
Mesopause: boundary of the mesosphere
The Thermosphere: Upper layer
Temperature increase with height
Auroras occur here
Fades into space

13. Earth-Sun Relationships
Energy that drives the weather and climate come from the sun
Solar energy is NOT distributed evenly
Varies with latitude, time of day, and season of the year
Unequal heating of the Earth creates wind’s and drives the ocean’s currents
Results in weather

14. Earth’s Motion
Rotation: spinning of the Earth about its axis (24 hours)
Revolution : movement of Earth in its orbit around the sun ( days)
Key Point: Seasonal changes occur because Earth’s position relative to the sun continually changes as it travels along its orbit.
Tilted 23.5 from perpendicular
Rotation and Revolution

15. What causes Seasons? NOT IN NOTES
Seasons are caused by the tilting of the earth on its axis
When the Earth is tilted towards the Sun – warmer seasons
When the Earth is tilted away from the Sun – cooler seasons

16. Summer Solstice:
June 21 or 22
First day of summer
“leaning” 23.5˚ towards the sun or Tropic of Cancer
Winter Solstice:
December 21 or 22
“leans” 23.5 away or Tropic of Capricorn

17. Equinox Autumnal Equinox September 22 or 23 First day of fall
Spring Equinox
March 21 or 22
First day of spring
Sun rays directly over the equator
Daylight and nighttime length are the same

18. Heating the Atmosphere
Heat: the energy transferred from one object to another because of a direct difference in their temperature
Temperature: measure of the amount of heat

19. Ways Heat Can be Transferred
Key Point: Heat is the energy transferred from one object to another because of a difference in their temperatures.
Conduction
The transfer of heat through matter by molecular activity
Transfer by touching
Collisions

20. Convection
The transfer of heat by a mass movement or circulation
Fluids
Radiation
Travels out in all directions
Doesn’t need matter

21. What happens to solar radiation?
Three Results:
Some energy is absorbed, causing temp to increase.
Water and air are transparent to certain wavelengths (goes through)
Some bounces off

22. What Happens to Solar Radiation?
Reflection
bounces off
30 % is reflected back to space
Scattering
Disperses light so travels in many directions.

23. Absorption: 50 % of the solar energy the Earth’s surface
20% is absorbed in the clouds
Greenhouse effect: heating of Earth from radiation being absorbed

24. Why Do Temperatures Vary?
A temperature control is any factor that causes temperature to vary from place to place and time to time.
Factors:
Heating of land
Heating of water
Altitude
Geographic position
Cloud cover
Ocean currents

25. Land and Water Temperatures
Land heats and cools more rapidly and to higher temperatures than water. Land also cools more rapidly and to a lower temperature than water.

26. Windward verses Leeward
Winds blow from ocean to shore, so wetter
Leeward:
Winds blow from land toward ocean, so dry
Mountains act as barriers

27. Altitude
Higher altitudes have cooler temperatures.

28. Albedo
the fraction of total radiation that is reflected by any surface.
Key Point: many clouds have high albedo and reflect the sunlight back to space.

29. World Distribution and Temperatures
Isotherms - lines on a weather map that connect points that have the same temperatures
Hot colors near equator , cool colors toward the poles

30. Picture and Graph Questions
Pg. 482
When do the sun’s rays strike 23.5?
When does summer solstice occur in the northern hemisphere?
When is the autumnal equinox occur in the southern hemisphere?
Pg. 490
Is Eureka or NYC the leeward city?
Which city has temperatures that are influences by ocean winds AND has cool summers and mild winters?
Pg. 492
What does cloud cover do to the day time temperatures?
What does cloud cover do to the nighttime temperatures?