| typhoon_tip |
| (Meteorologist) |
| Mon Oct 17 2005 08:45 PM |
Re: Tropical Storm Wilma Forms in the Western Caribbean
|
Quote:
This is sort of off topic, but I didn’t want to make a whole new thread about it.
‘Gravity waves’… that sounds interesting. I am assuming you are referring to those little radial pulses I keep seeing from the center (?). I just did a search but what I got was a bit over my head, and generally in context with mesoscale systems and the sort, not tropical cyclones. I seem to remember talking about them with Keith before, but I don’t think I understood them then either.
Could you explain their mechanics and function just briefly?
Thanks.
"Functionality" may be too complex for this forum. The short and skinny way of saying them, they are oscillations caused by the displacement of an air parcel which is restored to its initial position by gravity. This restoring force is dependent on native conditions to the parcel of air, such as lapse rate and moist adiabatic process for gravity waves born of convective processes, or dry adiabatic for clear are restoring momentum - which I think we all can agree is what takes place in Wilma is convective.
Gravity waves are not just restricted to mesoscale phenomena...though they do tend to exist at the mesoscale. Mid latitude bombogenisis and deep isentropic lift events also have been noted to produce these...and they can a beta-mesoscale, which is darn close to a regional synopsis. That is rarer, however... Mostly they are interesting organized band on clear days, sometimes seen in macro alto-cumulous sheets... Beautiful!! They are often characterized radial configuration emminating outward from the point of origin, which is vertically displaced air. Lee side mountain waves are gravity waves... Actually, so is the wake wave behind a boat in the ocean for that matter...
Is this helpful?