It is shown that drift wave plasma turbulence in the electromagnetic regime can significantly affect the zonal flow dynamics and drive zonal fields. A new interpretation of the effect of the zonal fields on the zonal flow stability is given as previous analytic predictions are shown to be inadequate for accurately describing the numerical results. The zonal flow/field excitation mechanism in the electromagnetic regime can provide a possible explanation for the observed correlation between transport barrier formation and low shear rational surfaces in the plasma.
