The parametric coupling processes of a large-amplitude electromagnetic pump wave with the temperature gradient drift instability in the high-latitude trough ionosphere have been studied. The modified growth rate of the temperature gradient drift instability in the presence of a high-frequency pump wave is computed for a range of pump amplitudes. We find that ground-launched radio waves with O-mode polarization can enhance or suppress temperature gradient drift instability-driven irregularities in the high-latitude trough ionosphere.