1. 11.2- State of the Atmosphere 11.3- Moisture in the Atmosphere
11.1- Atmospheric Basics
11.2- State of the Atmosphere
11.3- Moisture in the Atmosphere

2. Atmospheric Basics Atmospheric Composition
The majority of air is made up of oxygen(21%) and nitrogen(78%).

3. Atmospheric Basics Key Atmospheric Gases
Carbon dioxide and water vapor are two important gases that vary in amount but are critical in determine the amount of energy the atmosphere absorbs.
Heat is either absorbed or released when water changes state.
Three states in the atmosphere are liquid, solid, and gas.

4. Atmospheric Basics Ozone
A gas that controls the amount of ultraviolet light that enters the atmosphere is ozone, a molecule made up of three oxygen atoms.
Other major gases that can be found in the atmosphere include neon, helium, methane, krypton, hydrogen, and xenon.

5. Structure of the Atmosphere

6. Atmospheric Basics Layer Temperature Variation and Altitude
Composition
Special Characteristics
Troposphere
Decreases with altitude
Most of mass of atmosphere, water vapor
Most weather occurs here, pollution accumulates
Stratosphere
Increases with altitude
Concentrated ozone
Ozone layer
Mesosphere
No concentrated ozone
Upper boundary is the menopause
Thermosphere
Little atmospheric gases, molecules spread far apart
Ionosphere

7. Atmospheric Basics
The exosphere is the outermost layer of the Earth’s atmosphere.
Helium and hydrogen are found here.

8. stop

9. Atmospheric Basics Solar Fundamentals
Radiation is when energy is transferred by visible light, ultraviolet radiation, and other electromagnetic waves.
Conduction occurs when molecules collide.
Convection is the transfer of energy by the flow a heated substance.
Convection currents are the main mechanisms for the vertical motion of air that cause different weather patterns.
Winds form from convection currents.

10. Atmospheric Basics Reflection of the Sun’s energy. Effect Percent
Reflected by the atmosphere 6%
Absorbed by Earth surface
50%
Reflected from cloud
25%
Reflected from Earth surface 4%
Absorbed by atmosphere
15%

11. State of the Atmosphere
Temperature vs. Heat
Temperature is the measurement of how quickly or slowly molecules move.
Heat is the transfer of energy.
Heat flows from areas of higher temperature to areas of lower temperatures.

12. State of the Atmosphere
Temperature is measured the following ways.
Degrees Fahrenheit = oF
Degrees Celsius = 0C
Kelvin = K
There is no colder temperature known than absolute zero on the Kelvin scale.

13. Temperature Scales

14. State of the Atmosphere
Dew Point
The dew point to which air must be cooled at constant pressure to reach saturation, point at which air holds all the water vapor it possibly can.
Condensation occurs when matter changes from a gas to a liquid.

15. State of the Atmosphere
Vertical Temperature Changes
Temperature decreases as you go up
Lifted condensation level LCL:
Height where condensation occurs
Air rises, cools, condenses
Clouds: water vapor condensing

16. State of the Atmosphere
Air Pressure and Density
Air pressure
Weight of atmosphere above you decreases as you go up
Density
Air is more dense at surface of Earth and decreases as you go up

17. Air Pressure

18. State of the Atmosphere
Pressure –Temperature-Density Relationships
Temperature inversion is an increase in temperature with height in an atmospheric layer. (Temperature- altitude relationship is inverted.)
Step 1: Cool, clear winter night when the wind is calm
Step 2: Lower layers of atmosphere lose heat
Step 3: Lower layers of atmosphere become cooler than layers above.
Step 4: Temperatures increase with altitude, creating the temperature inversion.

19. Pressure-Temperature Graph

20. State of the Atmosphere
Wind
Cool air sinks, creating an area of high pressure.
Warm air rises, creating an area of low pressure
Air masses move from areas of high pressure to low pressure, which creates wind.
Measured in miles per hour
Wind is more varied on surface of Earth due to friction with water, land, trees, etc….

21. State of the Atmosphere
Relative Humidity
Humidity is the amount of water vapor in air.
Warm air can hold more water vapor.
Climates near the equator are more humid than climates close to the poles.
Relative humidity is the ratio of water vapor in a volume of air relative to how much water vapor that volume of air is capable of holding.
Given in %. Ex: 50% holding half the water it can

22. Moisture in the Atmosphere
Cloud Formation
Clouds can form as warm moist air rises, expands, and cools and cooler air sinks in a convection current.
Water vapor in the air condenses on a condensation nuclei such as dust or ice.
As more and more droplets collect, a cloud is formed.
Clouds also form from orographic lifting where moist air comes in contact with a mountain and rises.
Another type of cloud forms when air masses of different temperatures collide.

23. Cloud Formation

24. Moisture in the Atmosphere
Stability is the ability of an air mass to resist rising.
Air becomes unstable if it is cooler than the surface beneath it.
If temperature conditions are right and the air masses rise rapidly, it can produce clouds associated with thunderstorms.
Latent Heat is stored energy.

25. Moisture in the Atmosphere
Types of Clouds
Altitude
Strato: Low: below 2000m
Alto: Middle: 2000 – 6000m
Cirro: High: above 6000m (ice crystals)
Shape
Cirrus: wispy, stringy
Cumulus: puffy, lumpy
Stratus: featureless sheets
Nimbus: low, gray (rain)
Draw an example of each based off the slide.

26. Types of Clouds- Draw in notes

27. Moisture in the Atmosphere
Precipitation
Coalescence is the process that forms large droplets due to the collision of two cloud droplets.
Precipitation includes all forms of water both liquid and solid that fall from the clouds.
Forms of Precipitation are: rain, snow, sleet, and hail

28. Moisture in the Atmosphere
The Water Cycle
Precipitation- rain, ice, snow, etc…
Transpiration- water loss from plants
Evaporation- water to water vapor (gas).
lakes/oceans into air
Condensation- water vapor to water.
Dust; clouds
Runoff- water running into bodies of water

29. Water Cycle