Atmospheric Pressure

• Atmospheric Pressure


  The pressure exerted by the air around you
• Atmospheric pressure is acting on you at all times, and varies with your height above sea-level
• The Atmosphere


  • It is a layer of air that surrounds Earth
  • It is thin compared to the size of the Earth
• Atmospheric pressure is created

  Air molecules colliding with the surface
• As the altitude (height above Earth) increases


  Atmospheric pressure decreases
• High atmospheric pressure


  • At sea level
• Low atmospheric pressure


  • At high elevations
• As the altitude increases, the atmosphere gets less dense, so there are fewer air molecules that are able to collide with the surface
• As the height increases, there are fewer air molecules above a surface, so the weight of the air above it, which contributes to atmospheric pressure, decreases with altitude