  The inverse energy cascade in Charney-Hasegawa-Mima turbulence is
investigated. Kolmogorov law for the third order velocity structure function is
shown to be independent on the Rossby number, at variance with the energy
spectrum, as shown by high resolution direct numerical simulations. In the
asymptotic limit of strong rotation, coherent vortices are observed to form at
a dynamical scale which slowly grows with time. These vortices form an almost
quenched pattern and induce strong deviation form Gaussianity in the velocity
field.
