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Air presses on us from every side — so why do we never feel crushed by it?
![3.4.4 Atmospheric Pressure - Atmosphere and Climate - [Teachoo] - Concepts](https://cdn.teachoo.com/dc88c273-d005-4c07-976c-27e3d4964ec0/fig.-3.5.-the-pressure-inside-our-bodies-balances-atmospheric-pressure..jpg)
Atmospheric Pressure
Atmosphere
air around Earth
Pressure
force on a surface
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The pressure exerted by the weight of air on Earth; it decreases with altitude.
- Air has weight , so it presses on the Earth’s surface.
- This is called atmospheric pressure or air pressure.
- It is highest at sea level and decreases with altitude.
- This is because less air lies above us the higher up we go.
- Pressure also changes horizontally , based on temperature.
💡 DON’T MISS OUT
The air above us exerts a significant force on our bodies, and yet we do not feel it. This is because air presses on us from all sides, and our bodies exert a counter-pressure in response.
If temperature changes from place to place, how does that actually create high and low pressure?
How does temperature create pressure differences?
Warm air
Warm air is light, so it rises upward.
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Rising air
This creates a low-pressure area below it.
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Cold air
Cold air is heavy, so it sinks downward, creating high pressure.
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Wind always blows from high pressure towards low pressure.
- In hot areas, air heats up and rises , creating low pressure .
- Low pressure brings cloudy skies and wet weather .
- In cold areas, air is heavy and sinks , creating high pressure .
- High pressure brings clear and sunny skies .
- Air always moves from high pressure to low pressure .
