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F. M. Flasar (NASA/GSFC), D. P. Hinson, G. L. Tyler (Stanford Univ.)
Temperatures retrieved from Mars Global Surveyor radio occultations have been searched for evidence of waves. Emphasis has been on the initial series of occultations between 29\circ N and 64\circ S, obtained during the early martian southern summer, Ls=264\circ-308\circ. The profiles exhibit an undulatory behavior that is suggestive of vertically propagating waves. Wavelengths ~10 km are often dominant, but structure on smaller scales is evident. The undulatory structure is most pronounced between latitudes 29\circ N and 10\circ S, usually in regions of ``interesting'' topography, e.g., in the Tharsis region and near the edge of Syrtis Major. Several temperature profiles, particularly within 30\circ of the equator, exhibit lapse rates that locally become superadiabatic near the 0.4--mbar level or at higher altitudes. This implies that the waves are ``breaking'' and depositing horizontal momentum into the atmosphere. Such a deposition may play an important role in modulating the atmospheric winds, and characterizing the spatial and temporal distribution of these momentum transfers can provide important clues to understanding how the global circulation is maintained.