| Caption: |
Idealized diagram showing Earth and its atmosphere. The total force of the entire atmosphere is the product of the mass of the atmosphere and the acceleration of gravity. Both the mass and acceleration are constant; therefore, the total force from the atmosphere is constant. However, the air pressure at points on the Earth does vary because the mass of overlying air varies from place to place. Variations in the mass of overlying air are caused by differences in the temperature and density of air masses. Air pressure can be expressed as atmospheric force per unit area. (After Aguado, E., and Burt, J. E. 2007. Understanding weather and climate, 4th ed. Upper Saddle River, NJ: Pearson Prentice Hall) |
