Pressure and Wind
Why do we care if the air pressure increases or decreases?
What has that got to do with the weather?
Differences in air pressure lead to differences in forces, as
the barometer shows us. If this difference occurs out around us, rather than
in our barometer, it produces a pressure gradient across the land that
leads to a pressure gradient force pointing from high pressure to low
pressure. This pressure gradient force is the origin of wind.
On the Earth, the motion of air (wind) becomes more complicated
due to the rotation of the Earth and the friction of moving air across the
land surface. In part, these effects cause the air in high and low pressure
centers to circulate around the center of the pressure system.
highs, lows and fronts.