A greater explanation on the concept of pressure
 
  Pressure is when a fortis or fortis field acting over a small area that has a greater effect than the same fortis or fortis field acting over a larger area. The fortis is said to exert greater pressure when it acts over the smaller area. In contemporary science, the definition of pressure is "force per unit area" and it is calculated by dividing the force by the area over which it is acting. Because the Earth's atmosphere has weight (1m of air weighs about 12 1/4 newtons), it exerts pressure. Atmospheric pressure can be measured with a barometer.  
6.18.1 Falling pressure  
  Atmospheric pressure decreases with height. Close to Earth's surface, the height of a column of mercury supported by the atmosphere falls by about 1mm for every 11m increase in height above sea level. Atmospheric pressure at 16,000 is roughly 1/10th as great as it is at sea level.  
  At 100km, it has fallen to about one millionth of its sea level pressure.  
  Listed below and shown on the diagram right are pressures in millibars and the approximate height above sea level at which they are found.  
 
Pressure Height
1013.23mb 0m
1000mb 110m
900mb 990m
800mb 1950m
700mb 3010m
600mb 4200m
500mb 5575m
250mb 10,350m
100mb 16,180m
10mb 30,000m
1mb 50,000m
 
6.18.2 The concept of increasing/decreasing pressure with het and col  
  We know by watching the weather reports each night on television, that the pressure exerted onto the Earth's surface changes constantly. This is because the number of particles in the atmosphere changes according to the effects of sunlight and other surface based disturbances. A thick atmosphere weights more than a thin atmosphere, therefore surface pressure changes.  
  When the sun transmits tiny high moving particles towards Earth such as photons, they hit the atmosphere and transmit down to the surface. This creates reactions that releases added matter into the atmosphere, increasing the unit per volume, therefore we see an increase in pressure.  
  When we see these particles dissipate per volume area, we see that pressure decreases, therefore we see a lowering of pressure.  
  That is why forms of air that are called "highs" are associated with het air and "lows" are associated with col air. We also understand from our redefinition and usage of the terms het and col that a "low" will travel faster than a "high" and that high's tend to be slow moving, compared to lows. We can also see a velocity relationship to atmosphere in terms of the difference between high's and lows of atmospheric pressure.  
  When the surface atmospheric pressure drops from its median of around 1013mb to say 950mb, the velocity of winds increases dramatically. Closer to 900mb and we see the emergence of terrifying storms such a cyclones. (Col air moves faster than het air). When we see high's of say just 1030mb, we notice a significant increase in het.  
     
 
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