1. Explain the significance of Earth’s Atmosphere
Bell Ringer
Explain the significance of Earth’s Atmosphere

2. Introduction to the Atmosphere: Structure and Composition

3. What is Meteorology?
The study of weather, climate, and atmospheric processes

4. How Does Weather differ from Climate?
Weather is 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 to help describe a place or region

5. Composition of the Atmosphere
Main Components
Nitrogen – 78%
Oxygen – 21%
CO2 < 1%
Argon < 1%

6. What is the significance of Water Vapor?
Water vapor - source of all clouds and precipitation.

7. Ozone
• Ozone is a form of oxygen that combines three oxygen atoms into each molecule (O3)
• Ozone filters and absorbs harmful UV radiation by the sun
Ozone Video

8. Discussion Think about it…
How do humans affect the atmosphere?
Do we cause problems/issues?
Discuss this with a partner, take notes on your discussion in your graphic organizer

9. Human Influences and Primary Pollutants
Air pollution is airborne particles and gases that occur in concentrations large enough to endanger the health of organisms
Primary Pollution: emitted directly from identifiable sources
Secondary Pollution: not emitted directly into air (agriculture)

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

11. Pressure and Temperature Changes
The atmosphere rapidly thins as you travel away from Earth until there are too few gas molecules to detect.
Pressure Changes
As you increase in altitude, or travel away from Earth, pressure decreases
Temperature Changes
As you increase in altitude in the Troposphere the temperature decreases.

13. Layers of the Atmosphere
The atmosphere is divided into four layers based on temperature:
Troposphere
Stratosphere
Mesosphere
Thermosphere

14. The Troposphere The bottom layer
Temperature decreases with an increase in altitude.
Where weather occurs
Tropopause: boundary of the troposphere

15. The Stratosphere Above the troposphere
Temperature remains constant, then gradually starts to increase
Contains the ozone layer
Stratopause: boundary of the stratosphere

16. The Mesosphere Above the stratosphere
Temperature decreases with height
Mesopause: boundary of the mesosphere

17. The Thermosphere Upper layer of the atmosphere
Temperature increase with height
Auroras occur here
Fades into space
Why do you think temperatures increase in this layer?

18. Earth’s Motion (Revisited)
Rotation: spinning of the Earth about its axis (24 hours)
Revolution : movement of Earth in its orbit around the sun ( days)
The tilt of Earth’s axis causes seasons
Spins on its axis at a speed of 113,000 km/hr
Axis points to the North Star (Polaris)

19. What causes Seasons?
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

20. Solstice: The length of daylight and nighttime are different
Summer Solstice:
June 21 or 22
First day of summer
Longest daylight hour of the year
Winter Solstice:
December 21 or 22
First day of winter
Shortest daylight hours of the year

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

22. Exit Ticket
List the layers of Earth’s Atmosphere. Give one or more important fact(s) about each layer.

23. Bell Ringer
Given what you have learned about the atmosphere. How do you think the atmosphere affects the heating of Earth from the Sun?

24. The Heating of Land and Water

25. 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

26. Ways Heat Can be Transferred
Heat transfer from HOT to COLD objects
Conduction
The transfer of heat through matter by molecular activity
Transfer by touching

27. Convection Radiation The Heating Song
The transfer of heat by a mass movement or circulation within a substance
Radiation
Travels out in all directions
Solar energy reaches earth by radiation
The Heating Song

28. What Happens to Solar Radiation?

29. Reflection vs. Scattering
occurs when light bounces off an object.
30 % of all radiation is reflected back to space
Scattering produces a larger number of rays that travel in many directions.

30. Absorption:
50 % of the solar energy that strikes the top of the atmosphere reaches the Earth’s surface
20% is absorbed in the clouds
30% is reflected back to space

31. Why Do Temperatures Vary?
Factors:
Heating of land
Heating of water
Altitude
Geographic position
Cloud cover
Ocean currents

32. Geographic Position
As you move away from the equator the temperature drop

33. Windward verses Leeward
Windward -coastal areas with wetter, warmer conditions
Leeward- dry desert areas

34. Altitude
The higher the altitude the lower the temperatures.

35. Land and Water Temperatures
Land heats and cools more rapidly and to higher temperatures than water
Water – heats up longer and will retain the heat longer

36. Albedo
the fraction of total radiation that is reflected by any surface.
Daylight Cloud Cover
Clouds reflect solar radiation back to space
Temperatures are lower than on a clear day
Nighttime Cloud Cover
Clouds absorb radiation from land and reradiates some of it back to Earth
Temperatures are higher than on a clear night

37. World Distribution and Temperatures
Isotherms - lines on a weather map that connect points that have the same temperatures

38. Explain the three mechanisms of heat transfer.
Exit Ticket
Explain the three mechanisms of heat transfer.