In this manuscript, we derived a hierarchy of
equations (10) for the one-point moments
of the waveaction
. This system of equations has a
``triangular'' structure: the time derivative of the
-th moment
depends only on the moments of order
and 1 (spectrum). Their
evolution is not ``slaved'' to the spectrum or any other low moments
and it depends on the initial conditions. RPA allows the initial
conditions to be far from Gaussian and deviation of n'th moment from
its Gaussian level may even increase in a transient time dependent
state. Among two allowed extreme limits are the wavefield with a
deterministic amplitude
(for which
) and
the intermittent wavefields characterized by sparse k-space
distributions of
(for which
). However,
the level of intermittency (and non-Gaussianity in general)
exponentially decreases as WT approaches a statistically steady state,
as given by (13). Importantly, in some situations WT
might never reach a steady state (for example because of the
nonstationary pumping) or it might spend a long time in a transient
non-stationary state. In this case WT can be highly intermittent and
yet equations (10) are still valid for description of
such turbulence. In the other words, the type of intermittency
discussed in the present manuscript appears within the weakly nonlinear
closure and not as a result of its breakdown as in
[10]).
Acknowledgments Authors thank anonymous referees for constructive comments and Alan Newell for enlightening discussions. YL is supported by NSF CAREER grant DMS 0134955 and by ONR YIP grant N000140210528. SN thanks ONR for the support of his visit to RPI.