Air pressure varies because of the differences in air's density.
Inversely with altitude, the higher up you go the less air pressure
Humidity makes the pressure in an air mass increase
deminish
The air pressure can change, the temperature can vary and many more
The average air pressure in the thermosphere, which is the outermost layer of the Earth's atmosphere, is extremely low and can vary based on solar activity. Typically, the air pressure in this region is so low that it is considered a near vacuum.
When moves nothing is created except that there is a pressure difference left out.That will vary according to the speed of the air.
Different air pressure, so there is more/less air resistance.
Winds or breezes are caused by atmospheric pressure. When air is heated by the Sun, it warms and becomes less dense. This means that the parts of the air column making up the atmosphere vary between areas of warm air and areas of cold air. Areas of warm air are less dense and therefore have a low pressure as compared with areas of cold air which have a high pressure. To even out the pressure difference, the air flows from areas of high pressure to areas of low pressure and this flow of air is called the wind.
The pressure in the tank will vary from your cutin pressure to your cutout pressure. If you increased the pressure in the system, your air-charge will now be wrong. A good rule of thumb is cutin - 2 psi.
In every vehicle tired pressures will vary. Check in the driver door jam or owners manual for accurate tire pressure.
How does liquid pressure vary with depth
low pressure system and stormy weather