Physics
Seminar

Wednesday, September
15, 2004, 4:30 pm

Willet Science Center 101

James
H. Shirley

Jet
Propulsion Laboratory

A
Fourth Inertial Force

Inertial forces play an important role in general
circulation models of terrestrial, planetary, and stellar
atmospheres. We show here that the inertial forces arising due to
axial rotation in combination with orbital revolution differ from those due to
rotation alone. A new derivation yields the usual centrifugal, Coriolis,
and angular acceleration forces, together with one additional term. Like
the centrifugal force, this 'fourth inertial force' varies with location;
unlike that force, it varies substantially with time. The fourth
inertial force is typically about half the size of the Coriolis force for
synoptic-scale atmospheric motions in terrestrial middle latitudes; it has
apparently eluded direct detection and study because it has no radial
component. Many prior observations and a number of anomalous experimental
results may be explained by this hypothesis. The fourth inertial force
gives rise to continuous circulatory flows of geophysical and astrophysical
fluids.

*Please join us for light refreshments at 4:15pm
outside WSC 109.*