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Hi Alan,
Gravity waves due to CME shocks would ocurr in the ionosphere where the density is more than 4 orders of magnitude lower (and probably more like 6-7 orders of magnitude lower) than the density at the surface. This would not show up on a microbarograph! There simply isn't enough mass sloshing around in the ionosphere to effect the surface pressure, and in any event there is so much noise in a barograph trace due to weather.
Just for comparison, there are actually tides in the atmosphere (like in the oceans) due to the gravity of the moon. But there is so much noise in the barometric readings that these tides (which have an amplitude of 2-3mB out of a normal pressure of about 1000 mB) are only detectable under very steady atmospheric conditions such as under a very stable high pressure system. These atmospheric tides are many many orders of magnitude greater than any change in the ionosphere could cause.
I think I went on too long for this list, may be a better topic for a weather/geophysics list!
73 Warren K2ORS/WD2XGJ
FN42hi
-------------- Original message --------------
> Thanks Warren, I knew if I made outlandish enough suggestions someone would
> come up who knew the answer !! I wasn't sure of the definition but guessed
> at what you described. If there are gravity waves due to CME shocks, these
> should be detectable on a microbarograph ?? I keep wondering about playing
> in that area....trying to correlate the fading pattern with pressure
> changes......The problem could be the interaction is a "magnetic" collision
> and it wont correlate....but I wont know til I (or someone else ) try it.
> Cheers de Alan G3NYK
>
> ----- Original Message -----
> From: "Warren K2ORS/WD2XGJ"
> To:
> Sent: 05 January 2005 21:58
> Subject: LF: Gravity Waves
>
>
> > Alan,
> > The term "Gravity Waves" as used in geophysics (as opposed to
> astrophysics) refers to a wave at a density discontinuity whose restoring
> force is gravity. You are correct in making the analogy with waves on the
> ocean surface, ocean waves are a type of gravity wave. One can envison a
> similar phenomena wherever there is a pronounced disconinuity - such as at
> boundary between atmospheric or ionospheric layers (tropopause, stratopause,
> etc.)
> > In my mis-spent youth I did graduate studies in geophysics!
> >
> > --
> > 73 Warren K2ORS/WD2XGJ
> > FN42hi
>
>
>
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