ATMOSPHERIC PRESSURE 

Factors Influencing Atmospheric Pressure

1. Altitude

• Pressure decreases with increase in altitude because the column of air becomes shorter hence it exerts less weight.

1. Temperature

• When air is heated it expands and exerts pressure over a large area resulting in reduced pressure.
• When it’s cooled it contracts and exerts pressure over a small area resulting in increased pressure.

2. Rotation of the earth

• Rotation pushes air masses from poles towards the equator causing air to spread out and occupy more space causing it to expand making pressure to decrease.
• When air from the equator moves towards the poles it occupies less space causing it to contract resulting into high pressure.