Question

what are the variations of air pressure?

Answer 1

1) Variation with height or vertical variation:
2) Horizontal variation of pressure:

i)The equatorial low pressure belt :

ii) Sub – tropical high pressure belt:
iii) Low pressure belts near 600 latitudes:

iv) Polar high pressure belts

3. Diurnal variation:

Factors affecting atmospheric pressure:

Answer 2

Variation In Air Pressure :

$\implies$ As we move upwards through the atmosphere,the height of air column,above us,would decrease. This would result in a decrease in air pressure at higher altitudes. In fact,when we move towards higher altitudes, breathing can become difficult. Sometimes bleeding from nose may also occur. Most climbers,who attempt to scale high range mountains need to carry oxygen cylinders with them. For this very reason,aircrafts have Pressurised Cabins. The Air pressure in there is increased to a sufficient value that safeguards the passengers and the crew.

$\implies$ Air Pressure also varies with temperature and time at a given place.Due to uneven heating of earth's surface,air pressure can change rapidly. At a hotter place,the warm air there is lighter than the cooler air in the surrounding regions. Hence Air can rush in from high pressure surrounding area to this lower pressure area. This phenomenon can result in land breezes, sand breezes, winds and stroms.