Pressure differences exert a force and when not balanced by other forces cause movement. The force that results from pressure differences in a fluid such as our atmosphere is called the pressure force or the pressure gradient force . Air moves because of a pressure gradient force. In the above formula, density is expressed in units of kilograms per cubic meter, distance is measured in meters, and pressure is expressed in pascals or newtons per square meter. When pressure changes rapidly over a small distance, the pressure gradient force is large.
Strong winds result from large pressure gradients.
Return to Lesson 4 Page . Return to Weather For Pilots Main Page Local Madison Weather This web based lab section is being developed with assistance from the College of Letters and Science and the Cooperative Institute of Meteorological Satellite Studies.