Does Earth's Atmosphere Precess?
AbstractThe study considers a pair of sub-polar rings of atmospheric mass,
symmetric with respect to the equator, and rotating with respect to the
distant stars. Gravitational forces of the sun and moon exert a
continuous torque on the rings. In the absence of adequate mixing and
dissipation, geometrical constraints support a hypothesis of system
response in the form of precession. Analysis follows the classical
mechanics of rigid body rotation and the precession of the equinoxes.
Results yield a mean period of precession ranging generally over decadal
and centennial time scales depending on latitude. A scaling relation
yields a mean period of 37 years for rings at 60 degrees North and
South, while an alternate calculation more specific to the 2-ring system
yields a period of 43 years for rings at 68 degrees North and South. The
global net torque is negligible, but only because there is a large
cancellation between high and low latitudes. The result suggests a path
of investigation aimed toward im- proved projection of decadal
variability in atmospheric circulation, and by extension, ocean
circulation and climate.