ATSC 110 Lecture Notes - Lecture 2: Atmospheric Pressure, Pressure-Gradient Force, Sea Level
Document Summary
At higher elevations, there is less air molecules (pressure decreases) Pressure is dependent on the temperature and density of the air. R is a constant that depends on the composition of the air. T is temperature i. ii. iii. iv. v. f. g. If the air becomes colder in one column, the height will decrease. If the air becomes warmer in one column, the height will increase. Notice for a constant height level, the number of molecules above the warm column is greater than a cold column. Associated with low atmospheric pressures d. e. f. This creates a pressure difference at the constant height level. The difference creates a pressure gradient force which tends to move air from high pressure to low pressure. The movement of air would cause pressure to rise in colder column and pressure to fall in warmer column. Pressure changes in the atmosphere are small so pressure is usually measured in millibars measured in millibars i.