HIGH-RESOLUTION TEMPERATURE PROFILES MEASURED WITH STRATOSPHERIC BALLOONS NEAR THE ANDES MOUNTAINS

A spectral analysis of two balloon soundings of temperature performed in the troposphere and lower stratosphere over the Andes Mountains in Argentina with a vertical resolution of 10 m has been performed. The f irst and second soundings, launched at the same location, were perform ed during unusually calm and disturbed atmospheric conditions respecti vely. Considerable deviations from the -3 value predicted for the spec tral slopes in the power-law range by current saturation theories are found. These departures are reduced if the data resolution at disposal is diminished, thereby eliminating the highest wavelength harmonics. Slopes do not clearly steepen with increasing height as suggested by o ther authors and topography seems to be responsible for this fact at l ow altitudes. The spectral amplitude increase with height detected fro m recent lidar data is corroborated only in the sounding with calm atm ospheric conditions. Spectra are found to scale with the buoyancy freq uency not as simply as suggested by the saturation models.