  A model is developed to simulate micro-scale turbulence driven ZFs, and their
impact on the MHD tearing and kink modes is examined. The model is based on a
stochastic representation of the micro-scale ZFs with a given Alfv\'{e}n Mach
number, M_S. Two approaches were explored: i) passive stochastic model where
the ZFs amplitudes are independent of the MHD mode amplitude, and ii) the
semi-stochastic model where the amplitudes of the ZFs have a dependence on the
amplitude of the MHD mode itself. The results show that the stochastic ZFs can
significantly stabilise the (2,1) and (1,1) MHD modes even at very low
kinematic viscosity, Pr, where the mode is linearly unstable. Our results,
therefore indicate a possible mechanism for stabilisation of the MHD modes via
small-scale perturbations in poloidal flow, simulating the turbulence driven
ZFs.

Plasma Physics