1. Lesson 1
Atmospheric Basics

2. Atmospheric Composition…
Nitrogen – 78%
Oxygen – 21%
Argon - .93%
Carbon Dioxide - .03%
Water Vapor - .0 to 4%
Trace Gases

3. Key Atmospheric Components
Oxygen (O2)
Gas
Organisms need it to break down food for energy

4. Key Atmospheric Components
Carbon Dioxide (CO2)
Gas
Minor role in absorbing heat
plant fertilizer

5. Key Atmospheric Components
Ozone (O3)
Gas
Absorbs ultraviolet radiation from the sun

6. Key Atmospheric Components
Water Vapor(H2O)
Gas
Major role in absorbing heat
source of condensation for clouds

7. Key Atmospheric Components
Water
Liquid
source of rain
Singing in the Rain!

8. Key Atmospheric Components
Ice
Solid
Makes up snow, sleet, & hail
Legendary Vail Powder!

9. Key Atmospheric Components
Dust, Salt, Volcanic Ash
Solids
Provide solid surface for water vapor to condense (so that clouds can form)
Condensation nuclei
See next slide…

10. Condensation Nuclei…

11. The Structure of the Atmosphere – The Troposphere
Description…
Tropo- (change)
0-11 km
highest air pressure
Contains most gases of the atmosphere
Objects Found There
Weather
life forms
jets

12. The Structure of the Atmosphere – The Stratosphere
Description…
Strato- (layer)
11-48 km
Molecular heat rises due to ozone layer absorbing UV radiation
Objects Found There
Ozone layer
Weather balloons

13. The Structure of the Atmosphere – The Mesosphere
Description…
Meso- (middle)
48-95 km
Temperature falls b/c there’s not a whole lot here!
Objects Found There
Meteors (shooting stars) burn here

14. The Structure of the Atmosphere – The Thermosphere
Description…
Thermo- (heat) km
Molecular heat rises
Objects Found There
Ionosphere
Auroras

15. The Structure of the Atmosphere – The Exosphere
Description…
Exo- (outside)
Above 600 km
Outermost layer
Space!
Objects Found There
Some H and He
Satellites

16. Temperature Variations with Altitude
The layers are determined by temperature!

17. What Happens to the Sun’s Energy?

18. Solar Fundamentals…
a. Radiation
transfer of energy through space (by electromagnetic waves - visible light, uv radiation, etc)
Surface warmed by the sun’s rays

19. Solar Fundamentals… Air molecules warmed by surface a. Conduction
transfer of energy by contact (when molecules collide)
Air molecules warmed by surface

20. Solar Fundamentals… transfer of energy by… flow of a heated substance
a. Convection
transfer of energy by… flow of a heated substance
Warm air rises, cools & sinks

21. The State of the Atmosphere
Lesson 2
The State of the Atmosphere

22. Temperature of the Atmosphere…
1. What is temperature?
…measurement - how rapidly or slowly molecules move
Why is the temperature of the lower atmosphere cooler at higher elevations and altitudes?
… b/c it is farther away from the source of heat – conduction from Earth’s surface

23. Temperature of the Atmosphere…
1. What is temperature?
… Individual air masses moving upward through the atmosphere… will cool about 10 degrees C/1000 m.
Think… Pilot Mountain or Boone

24. Temperature of the Atmosphere…
2. What is heat?
…transfer of energy that occurs because of a difference in temperature between substances
a. Heat fuels atmospheric processes!

25. The Temperature of the Atmosphere
b. The thermosphere is the hottest layer of the atmosphere but it feels so cold…
b/c even though molecules are moving very fast (which means they are very hot), they are so far apart that there is no heat transfer.

26. The Temperature of the Atmosphere
3. Dew Point - temperature to which air must be cooled (at constant pressure) to reach saturation.
Dew point tells us how much water is in the air.
This is when dew is formed!
The higher the dew point, more humid and uncomfortable the air.
See next slide…

27. The Temperature of the Atmosphere
3b. Dew point is also called condensation temperature
b/c it’s the temperature at which condensation occurs.
(Remember the condensation nuclei?)

28. Vertical Temperature Changes
3c. How is dew point determined?
… determine the temperature at which dew (condensation) forms by cooling the air.

29. Humidity Changes with Temperature…
4. What is humidity?
The amount of water air can hold at a given temperature. This is a constant!
What is relative humidity?
The amount of water the air is actually holding compared to how much it can hold
Relative humidity is determined by....using a wet/dry bulb thermometer & a relative humidity chart

30. Air Pressure and Density…
Density is mass (of air) per volume.
Air pressure is…
… force exerted by molecules of atmosphere as they are pulled toward Earth’s center by gravity.

31. Air Pressure and Density…
2b. Air at the bottom of the atmosphere (troposphere) has higher density and pressure because...
… of the greater mass of the atmosphere above you (it contains the most gases)
… This is similar to being at the bottom of the ocean with tons of water above you!
… We are accustomed to the high air pressure so it doesn’t squash us.

32. Temperature-Density Relationship
1. Warm Air…
a. As temperature increases… air becomes less dense.
b. Warm air is less dense and will rise.
c. The upward movement of warm air lowers pressure.
d. So, warm air rising causes low pressure.

33. Temperature-Density Relationship
2. Cold Air…
As temperature decreases… air becomes more dense.
Cold air is more dense and will sink.
The downward movement of cold air raises pressure.
So, cold air sinking causes high pressure.

34. Temperature Inversion
3. Temp. Inversion- upper layers of troposphere are warmer than lower layers.
Warmer layers are above colder layers.
Cause: on cold, clear, winter night, surface cools rapidly & becomes colder than air above it
Effects:The warm layer can trap pollution or melt snow
d. Draw this…

35. 1. Creating Wind… Cool air, which is denser, sinks.
1. Creating Wind…
Cool air, which is denser, sinks.
This forces the warm air, which is less dense to move up.
Air moves from areas of high density to areas of low density.
In its simplest form, wind can be thought of as air moving from an area of high pressure to an area of low pressure.

36. Wind…
The density imbalances that move air to produce wind are created by…
The unequal heating of Earth’s surface
Wind is measured by…
anemometers (mph or kph)
Wind speeds increase at high altitudes b/c…
There are few to no obstacles there

37. Humidity Changes with Temperature…
3. How much water vapor can a m3 of air hold at 25 degrees C?
24 grams
4. How much water vapor can a m3 of air hold at 15 degrees C?
13 grams
5. Why does the air hold more water at 25 degrees than it does at 15 degrees C?
Warm air can hold more water than cold air because it is less dense.
6. How much water (per m3) would the air hold in a room at 25 degrees C if the relative humidity was 50%?
12 grams

38. Moisture in the Atmosphere
Lesson 3
Moisture in the Atmosphere

39. Three Ways Clouds Can Form…
a. from convection currents
b. from warm air rising over mountains (orographic lifting)
c. when air masses of different temperatures meet

40. Cloud Formation – Convection Currents

41. Cloud Formation – Orographic Lifting
Clouds form over a mountain.

42. Orographic Lifting – Mt. Washington, NH

43. Cloud Formation – Frontal

44. Cloud Types…Altitude Cirro- high Above 6000m Alto - middle
Between m
Stratus - low
Below 2000m

45. Cirrus Latin for “hair” Wispy, stringy clouds
Cirrus over Whidbey Island, WA

46. Cloud Types Cumulus Latin for “pile” or “heap” Puffy, lumpy clouds
Altocumulus

47. Altocumulus from 30,000 ft!

48. Cirrostratus “halo” around sun
Cloud Types
Stratus
Latin for “layer”
Featureless sheets of clouds
Stratus clouds over Palm Coast, FL
Cirrostratus “halo” around sun

49. Cloud Types Nimbus Latin for “cloud” Low, gray rain clouds
Nimbostratus

50. Latin for “puffy cloud”
Enormous storm clouds
Cumulonimbus

51. More Clouds!

52. Lesson 3 Cloud Model… p. 288 Create 10 clouds.
Get a piece of blue paper.
Title it “Clouds” and write your name(s) on the bottom left.
Draw the ground.
Mark the altitude on left side.
Draw a sun.
Glue the clouds on and label them.
Draw rain drops under the 2 nimbus clouds.