why air pressure is higher on earth's surface than above?

Question

air goes from high pressure area to low,so why air pressure is not same all over.it go on decreasing as we go above surface.

Answer 1

Atmospheric pressure is the pressure above any area in the Earth's atmosphere caused by the weight of air.
Air masses are affected by the general atmospheric pressure within the mass, creating areas of high pressure (anti-cyclones) and low pressure (depressions). Low pressure areas have less atmospheric mass above their location, whereas high pressure areas have more atmospheric mass above their location.

As elevation increases, there are exponentially fewer and fewer air molecules. Therefore, atmospheric pressure decreases with increasing altitude at a decreasing rate.
A column of air, 1 square inch in cross section, measured from sea level to the top of the atmosphere would weigh approximately 14.7 lb. A 1 m² column of air would weigh about 100 kilonewtons. See density of air.

Pressure changes quickly but smoothly between the earth's surface and outerspace. The following is a list of air pressures (fraction of one atmosphere) with the corresponding average altitude. To find the pressure (in kPa or % atm) at any altitude (in feet or meters), you can use the eXtreme High Altitude Calculator

fraction 1 atm avg altitude in meters
1 0
1/2 5486.3
1/3 8375.8
1/10 16131.9
1/100 30900.9
1/1000 48467.2
1/10000 69463.6
1/100000 96281.6

Answer 2

Density just like water air is a fluid and the more you add to make the column taller the higher the pressure is at the bottom. Air is just a lot less dense than water. So for 33 feet depth in water is equal to 14.696 PSI 45,000 feet of air is equal to 14.696 PSI The value of 14.696 is called one atmosphere, which is the pressure at sea level. Now the reason 33 feet below the surface of water is also called 1 atmosphere is that aerospace and marine science reference a different datum point of where zero is.

Answer 3

Have you ever been in a big pile of people? How the lower ones feel the most pressure and weight pushing them. It's the same thing with air.

At sea level there is very much air on top of everything. When you go higher there is less and less air above you, thus less pressure.

Answer 4

There 2 reason for air pressure not being even everywhere...

1. Hot air rises & cold air sinks.. as we all know at altitudes the air density is less so the air get cold & rushes downwards.. creating a downward force....
2. At surface of oceans all evaporated water is mixed in to air to make heavy & dense so it make more pressure at the sureface...

These two types of air cannot rise from high pressure to low becoz of their density & temparature...

Moreover in a cyclindrical coloum full of liquid the pressure is highest at the bottom due to full coloum exerting pressure downwards... same way if we consider the atmosphere a big coloumn... the pressure is more at bottom where there is highest density & above the density is low....

Answer 5

The air pressure at any particular altitude is mainly based on the weight of the air that sits on top. For an analogy, imagine that your have a person sitting on your shoulders; on top of that persons shoulders sits another person...and so on. The lower you are in this chain the more weight you feel. It is the same for air in the atmosphere: the air higher up compresses the air that is lower with its weight.

Answer 6

Try to imagine that when you stand at sea level there is a column of air above you at pressure X. when you gain elevation i.e climb a mountain that column is getting shorter that's how the pressure is smaller.

Answer 7

Because air on mass of air on top compresses air below it. this happens progressively. therefore pressure is higher near the surface

Answer 8

Molecules constituting the air has mass right? If it has mass it is subject to gravitation right?
The closer you come to the center of gravity of any mass the gravitationnal pull is bigger right?
That's why we would weight a bit less on mount everest than in the bottom of a dry ocean!
Same thing applies here.

Answer 9

Well yeah... your right high pressure always go to the low pressure... except when you factor gravity.

Gravity is pulling much of the air molecules lower to the surface...

Jed B.
Webmaster
http://www.IdealWeightNaturally.com

Answer 10

because there are more layers of air on the surface of the earth, like in a swimming pool... the presion is high when the depth increases.