decreases
The pressure of the earths atmosphere, as with any fluid, increases with the height of the column of air. In the case of earths atmosphere, there are some complications. The density of the air is not uniform but decreases with altitude. Additionally there is no distinct top surface from which height can be measured. We can, however, calculate the approximate difference in pressure between two altitudes using the equation . The average pressure of the atmosphere at sea level is 1.013 10 5 Pa. This pressure is often expressed as 101.3 kPa.