Density and Air Pressure Lesson

Air density is the amount of AIR in a given area

Density DECREASES as altitude (height) INCREASES

COLD air is more dense than warm air

Cold air SINKS 

Warm air RISES 

Air pressure is the FORCE air molecules exert on each other and their surroundings 

Air pressure DECREASES as altitude (height) INCREASES

This is because there is more DISTANCE between the air molecules 

Air moves from areas of HIGH to LOW pressure 

Hot Temperature= LOW air pressure

Cold Temperature=HIGH air pressure 

High pressure generally means FAIR weather

Air mass in upper atmosphere is SINKING 

Few or no CLOUDS

Low pressure generally means CLOUDLY, RAINY weather

Air masses move APART

Warm air RISES 

Clouds form