  Hasegawa-Wakatani system, commonly used as a toy model of dissipative drift
waves in fusion devices is revisited with considerations of phase and amplitude
dynamics of its triadic interactions. It is observed that a single resonant
triad can saturate via three way phase locking where the phase differences
between dominant modes converge to constant values as individual phases
increase in time. This allows the system to have approximately constant
amplitude solutions. Non-resonant triads show similar behavior only when one of
its legs is a zonal wave number. However when an additional triad, which is a
reflection of the original one with respect to the $y$ axis is included, the
behavior of the resulting triad pair is shown to be more complex. In
particular, it is found that triads involving small radial wave numbers (large
scale zonal flows) end up transferring their energy to the subdominant mode
which keeps growing exponentially, while those involving larger radial wave
numbers (small scale zonal flows) tend to find steady chaotic or limit cycle
states (or decay to zero). In order to study the dynamics in a connected
network of triads, a network formulation is considered including a pump mode,
and a number of zonal and non-zonal subdominant modes as a dynamical system. It
was observed that the zonal modes become clearly dominant only when a large
number of triads are connected. When the zonal flow becomes dominant as a
'collective mean field', individual interactions between modes become less
important, which is consistent with the inhomogeneous wave-kinetic picture.
Finally, the results of direct numerical simulation is discussed for the same
parameters and various forms of the order parameter are computed. It is
observed that nonlinear phase dynamics results in a flattening of the large
scale phase velocity as a function of scale in direct numerical simulations.
