Re: planetary and atmospheric rotation - origins, direction, etc

: Crown-Horned Snorkack <chornedsnorkack@[EMAIL PROTECTED]
>
: Well, the rotation of atmosphere causes Coriolis forces in that
: reference frame, sure.

Still seems backwards to me.  The use of a rotating system of coordinates
causes the coriolis forces on the atmosphere.  Or "pseudoforces",
depending
on how you look at it, or how you want to use your terminology.

: But what about rotation of atmosphere with respect to the underlying
: solid ground (like west winds on Earth)?  Is it caused by the rotation
: of the solid grouns with respect to inertial frame? 

Your terminology is still thowing me a bit, but I think the
answer is "no".  Winds are caused by thermal gradients.  They are
organized into bands by coriolis forces, but that has little to do
with what the ground is doing, as such.

: If you have a planet which does not rotate with respect to inertial
: frame, could its atmosphere rotate with respect to the solid ground? 

If it's receiving uneven illumination, there would be winds (and maybe
even if the illumination was even; the wind's just wouldn't be organized
into bands in the same way).  Whether you'd call this "rotation",
I don't know.

: Assuming that the day and night hemispheres and tidal bulges
: progressively move with orbital revolution? 

I suppose the movement of a tidal bulge following the aparent direction
of the primary around which the planet orbits could "pump" air, but such
an effect would be swamped by thermal movements, and again, it wouldn't
be organized the way winds are on earth.  The thermal movements could
also cause a net movement of the atmosphere, following the lightsource,
but again, almost undetectably small compared to winds convecting heat
to the darkside.  Lost in the noise, in the general un-even-ness of the
terrain, etc.

Not sure I've answered your question, though.  I guess the bottom line
is, a planet not rotating wrt an inertial frame isn't going to have
winds organized into bands as on earth, jupiter, whatnot.  Some nits
can be picked wrt "frame dragging", but then you're talking either
horrifically small effects, or horrifically exotic environments with
very, very dense, fast-moving objects.


Wayne Throop   throopw@[EMAIL PROTECTED]
   http://sheol.org/throopw