how does this pressure react to the atmosphere?
Within the atmosphere, the ambient pressure decreases as height increases.
Ambient pressure
Within the atmosphere, the ambient pressure decreases as height increases. 
two scuba divers are 50 m below the surface of the water UNANSWERABLE what is this sickness about? It is a condition arising from dissolved gases coming out of solution into bubbles inside the body on depressurisation what are some of the causes this sickness? Reduction in ambient pressure and when leaving a high-pressure environment, ascending from depth, or ascending to altitude.
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Ambient pressure [SEP] Atmosphere
Within the atmosphere, the ambient pressure decreases as height increases. By measuring ambient atmospheric pressure, a pilot may determine altitude (see pitot-static system). Near sea level, a change of ambient pressure of 1 millibar is taken to represent a change of height of .