OBSERVATIONS OF INERTIA-GRAVITY WAVE MOTIONS IN THE STRATOSPHERE OVERJICAMARCA, PERU

We present results obtained with the MST radar at Jicamarca, Peru over 10 days in January, 1993. During this campaign, inertia-gravity waves with observed periods of similar to 36 hours were seen in the stratos phere (19-30 km). The radar was operated with a high (400-m) range res olution allowing accurate determination of wave propagation characteri stics. The large variation of wave amplitude (similar to 2-10 ms(-1)) with height and time suggests a superposition of several wave motions. As consistent with upward energy propagation, the phase fronts descen ded with time, and a vertical wavelength of similar to 5 km was inferr ed from the rate of this phase descent. Orbital ellipses imply largely zonal propagation with an intrinsic period of roughly 30 hours, somew hat less than the observed period. The shorter intrinsic period sugges ts eastward wave propagation, in opposition to the predominantly westw ard mean motion.