Bell Ringer

1
Bell Ringer

• What is the most important gas in the atmosphere?

2
Water Vapor and the Atmosphere
3
Water in the Atmosphere

• Precipitation is any form of water that falls
  from a cloud.
• When it comes to understanding atmospheric
  processes, water vapor is the most important gas
  in the atmosphere

4
Water Changes State

• The three states of matter solid, liquid, and gas
  (plasma is the fourth)

5
Water Changing State

• Melting
• Solid to Liquid
• Latent Heat does not produce a temperature
  change.
• Evaporation
• Liquid to Gas
• Condensation
• Gas to Liquid

• Freezing
• Liquid to Solid
• Sublimation
• Solid to Gas
• Deposition
• Gas to Solid

6
Think about it

• Have you ever been outside and the air seemed
  sticky or wet? Maybe it gave you frizzy
  hairwhat causes this?
• TURN AND TALKdiscuss this with your partner

Video Link http//www.youtube.com/watch?v7GS5jl
4nLek
7
Humidity

• amount of water vapor in air.

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Saturation

• The state when air contains the maximum quantity
  of water vapor that it can hold at any given
  temperature and pressure.
• The amount of water vapor required for saturation
  depends on temperature
• When saturated, warm air contain more water vapor
  than cold air.

9
Relative Humidity

• Ratio of the airs actual water-vapor content
  compared with the amount of water vapor air can
  hold at that temperature and pressure.
• Lowering air temperature causes an increase in
  relative humidity
• Raising air temperature causes a decrease in
  relative humidity

10
Dew Point

• Dew point is the temperature to which a parcel
  of air would need to be cooled to
• reach saturation.

11
Dew on a Spider Web
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Measuring Humidity

• Instrument Hygrometer
• Psychrometer a type of hygrometer consisting
  of two identical thermometers mounted side by
  side
• Dry bulb give the present air temperature
• Wet bulb has thin wet wick tied around the end

13
Sling Psychrometer
14
Think about it

• THINKthen TURN AND TALK to your neighbor
• What is the difference between moisture and
  humidity?
• Where are the most humid places on Earth?