Jamiewx
(Storm Tracker)
Sat Jun 12 2004 10:40 PM
Divergence and Vorticity

Hey Guys

Is there anyone that can explain what Divergence and Vorticity is and how it affects tropical cyclones. I see maps online all the time and don't how to use them


HanKFranK
(User)
Sun Jun 13 2004 10:28 PM
Re: Divergence and Vorticity

i can give you an idea.. may be 'right' but probably not on the money, scientifically.
vorticity is sort of like angular momentum, but in a fluid... in this case air. it's the tendency for something to continue gyrating, a ripple of lower pressure in the atmosphere with coriolis deflection working on it. it isn't necessarily a closed, circular turning, it may just show as a 'hook' in the wind field. a vorticity maximum is often the focal point for a developing tropical system.
divergence is a 'split' in an air current. when we're thinking of it in terms of tropical weather, it's the stuff happening at high altitudes, jet stream level (around 200mb for instance). when you have a forking in the upper air currents, the air below rises to take its place, think of it sort of like a siphon working on the air parcel below. i'm not sure if you'd call it dynamic forcing. anyway, rising air condenses, usually feeds convection, provides proper ventilation. it can work as a makeshift outflow jet for a developing tropical cyclone.. thats why the location and track of the system relative to the upper air flow is so important.. upper air winds can work for a tropical system (divergence or an outflow jet) or against (wind shear), and have a great deal of the influence in steering most tropical systems.
hope you can use some of that...
HF 0229z14june



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