Meteorological balloon measurements were applied to investigate gravity waves in the stratosphere above three weather stations in the Canadian Arctic. It was found that a distinct enhancement in the amount of wave activity occurred at each of the three stations simultaneously while a tropospheric jet stream crossed the Arctic during mid-November of 1996. An interpretation is proposed in which the enhanced wave activity occurs as the tropospheric jet provides conditions that are favourable for the upward propagation of mountain waves. Further propagation into the stratosphere is then facilitated during winter when the tropospheric and stratospheric jets coincide. ¿ 1999 American Geophysical Union