1. The earths _is a thin layer of gas, held to the planet by gravity
2. Compared to the planets size, this layer is very small and fragile?
3. Make up most of our air, but the last 1% is important to?
a. Oxygen (21%)
Air Masses and Fronts
1. Periods of extreme heat or cold are caused by moving?
a. Air masses
2. Two uniform characteristics?
b. Moisture Content
3. Depends on a source area (pole vs. equator)
a. Air Temperature
Thunderstorms and Tornadoes
1. Storms form when the atmosphere is disrupted by currents of?
a. Rising Air
2. _pressure sucks air upward, often creating strong swirling winds?
a. Low Air
3. The most common storms in the US are?
Humidity and Air Pressure
1. The amount of moisture in the air?
2. How much actual water vapor is contained in the air?
a. Absolute humidity
3. The amount of water vapor in the air relative to the total amount it could hold?
a. Relative Humidi