(06-09-2018, 12:59 AM)CarlosPindle Wrote: in the Northern the High Pressure systems rotate clockwise and the Low Pressure systems counter-clockwise. But, in either is the air rising or falling? Bowditch Chapter 34 Weather Elements doesn't make it clear.
Carlos
Hello Carlos,
No, Im not a weather guru, but i try to pay attention. When you see a tornado or a hurricane you are watching an extreme example of a low pressure system. Just watch what happens in and around a tornado and you get the general picture of weaker wide-spread lows.
The reason you can see a tornado is because of all the crap it picks up. We sense wide area lows with barometric pressure and wind direction/velocity. A High is never as intense (except perhaps micro-bursts) and behaves just the opposite of a low.
The sail of a ship or the wing of an airplane creates on one side an area of low pressure which draws the wing or sail in that direction... The bottom of the wing or sail is an area of high pressure. Low pressure means, I think?, low density air. Put your hand in front of a fan and you feel a high... put your hand behind the fan and you feel a low.
Cold air is dense; warm air is less dense. The fan itself, or the propeller of an airplane, is an engine that modifies air density - the engine that creates lows and highs in nature are the relative temperatures of air masses that cause them to rise or fall. Coriolis effect modifies the direction of the wind (as I recall) into a circular pattern... otherwise the wind would rush directly into a low pressure area where it would then be drawn up into the sky.. When the heat engine (temperature differential) quits the tornado ends.... I think!
Moisture plays a big roll too. When a cloud creates rain the act of condensation releases more heat which causes a storm to intensify. Evaporation subtracts heat.
Whether the lifting source is orographic or adiabatic the effect is the same - weather. Warm air rises; cold air sinks. Apply these principles to water and you understand why liquid boils as it does. Or ask yourself this... Why does a hydrogen or helium balloon rise?
I hope I remembered correctly.
joe