Generation of inertial waves, jets and vortices in astrophysical turbulence
Nordita Astrophysics seminars
Wednesday 22 February 2012
from 13:30
to 14:30 at
122:026
Speaker :
Nathan Kleeorin (Ben-Gurion University of the Negev, Beer-Sheva)
Abstract :
We discuss a nonlinear stage of a large-scale instability in a
sheared nonhelical turbulence. This instability causes generation of
large-scale vorticity. The nonlinearity is determined by the budget
equation for the turbulent kinetic energy and results in increase of
the turbulent viscosity with the increase of the mean vorticity. In
addition, this instability in nonlinear stage causes the generation
of kinetic helicity. We also discuss a mechanism of excitation of
the large-scale inertial waves and jets in a rotating inhomogeneous
(or density stratified turbulence) due to an excitation of a
large-scale instability. This instability is caused by a combined
effect of the inhomogeneity of the turbulence and the uniform mean
rotation. The source of these large-scale instabilities is the
energy of the small-scale turbulence. Applications to astrophysical
and geophysical turbulence is discussed.
