Pressure $$\mathit{\Pi}(h)$$ as a function of height $$h$$ decreases exponentially with height. At the bottom (e.g. at sea level) the pressure $$\mathit{\Pi}_0 = \mathit{\Pi}(0)$$ is the highest. The exponential curve of the pressure is described by the barometric formula. How fast the pressure drops with altitude depends on the scale height $$H$$.