“Water in the ATM”
18.1
•	Water Vapor is the source of all C______________ and P_____________
•	Water Vapor = Most Important Weather Gas!

3 States of Water
•	Liquid = “ Water ”
•	Solid = “      ”
•	Gas = “            ”

Changing States takes Energy!
•	S  L
–	Latent Heat = 
	No tempo change
–	Latent = “Hidden”
–	Melting
•	L  G
–	Evaporation
–	Ex: Step out of shower…cold!
•	G  L
–	Condensation
–	Heat is released!
•	S  G
–	Sublimation
–	Ex: Dry Ice.

•	G  S
–	Deposition
–	Ex: Frost.

Humidity
Amount of Water Vapor (gas) in Air.

Saturation.
•	When no more water vapor can be stored in air.
–	Warm air = ↑water vapor possible
–	Cold air   = ↓water vapor possible

Dew Point
•	Tempo when air will reach saturation.