The ratio R between the spectral kinetic and potential energies as a function of vertical wavenumber has been calculated from high-resolution data obtained with open stratospheric balloons near the Andes Mountains. Two segments of altitude in the troposphere and stratosphere respectively were analyzed. The ratio values are larger in both the troposphere and stratosphere than those predicted from the separability of wavenumber and frequency spectra. A comparison was made with previous statistical results from soundings over flat terrain extending up to log m(cy/m)=-2.0. Our calculations prolong this interval to -2.0≤log m≤-0.7. In the stratosphere, a remarkable similarity between that earlier work and ours is observed. This also happens in the troposphere, but only up to log m=-1.4. As suggested by the other authors, the enhanced R values might be explained by the propagation of inertial gravity waves generated in the mountain relief (this is supported by rotational spectra calculated here). Previous evidence in favor of spectral separability obtained by other authors has been extended here for larger wavenumbers by the observed constancy of the ratio between the temperature and vertical velocity spectra. In both the troposphere and the stratosphere, this ratio appears to be fairly uniform and similar to previous results obtained by other authors at lower resolution. ¿ 1999 American Geophysical Union