Re: gravitational force -airplane motion and earths rotation

From: N:dlzc D:aol T:com \(dlzc\) (net_at_nospam.com)
Date: 08/26/04 

Date: Wed, 25 Aug 2004 20:56:56 -0700

Dear Richard Herring:

"Richard Herring" <junk@[127.0.0.1]> wrote in message
news:5O+GvPvOvKLBFwgg@baesystems.com...
> In message <Q31Xc.23650$L94.7232@fed1read07>, "N:dlzc D:aol T:com
> (dlzc)" <N@?.D.invalid> writes
> >Dear Richard Herring:
> >
> >"Richard Herring" <junk@[127.0.0.1]> wrote in message
> >news:M6kLCNClKFLBFw1w@baesystems.com...
> >> In message <%ZHWc.21283$L94.10839@fed1read07>, "N:dlzc D:aol T:com
> >> (dlzc)" <"N:dlzc1.D:cox.T:net"@nospam.com> writes
> [...]
> >> >
> >> >Google "jet stream". It wanders around, but always goes generally
> >> >west-to-east. Almost all airports have a runway that is
west-to-east.
> >> >
> >> That's to match the prevailing surface wind, nothing to do with the
jet
> >> stream.
> >
> >And the two are simply coincidental?
>
> Yes. Quite often they're in opposite directions.
>
> >Local surface geometries do affect
> >the exact orientation chosen for the landing strips.
>
> Quite often the winds in these parts are easterly, and it's nothing to
> do with local surface geometry.
>
> >But barring that, the
> >effects of the jet stream (or even the cause of the jet stream) go all
the
> >way down.
>
> Certainly some of their effects are discernible at ground level, but a
> constant westerly wind is not one of them. You may not recall it, but
> the existence of jet streams was not even known until military aircraft
> started flying high enough to be affected.

I do vaguely remember this.

> > That is the nature of a fluid.
>
> At temperate latitudes we have these things called cyclonic weather
> systems. You may have noticed them; they often start life as hurricanes.
>
> They do indeed travel west to east with the jet stream, but whenever
> they pass by on the equatorward side of us, the geostrophic wind (which
> is what dominates at low levels) comes from the east.

Accepted. And thanks! Flatlander training goes pretty deep.

David A. Smith

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