Two barometers are placed one kilometer apart. One shows higher pressure than the other. What will happen to air between them?
1 Answer
Not exactly what you think.
Explanation:
Stand with your left hand toward the barometer that shows the lower pressure. The wind will be at your back with a slight veer towards the lower pressure. (This is if you are in the Northern Hemisphere. In the Southern Hemisphere the wind would be in your face)
What happens is the air will move from the high pressure to the low pressure (pressure gradient force), but it will be deflected by something called the Coriolis effect. This effect is essentially like trying to draw a straight line on a spinning piece of paper. The line will curve due to the spin. This deflects the wind so that with your left hand at the low pressure the wind will be at your back (in the Northern Hemisphere).
The reason the air in this example slightly veers in toward the low is the force of friction. As the air moves over the ground it is slowed due to friction. Since the Coriolis effect is dependent on the pressure gradient force, when you slow the wind the Coriolis is less and the air gradually circles into the low pressure center.
