Wavelet techniques applied to lidar temperature profiles in the middle atmosphere to study gravity waves

This paper puts forward wavelet based tools such as continuous wavelet transform, multiresolution and wavelet packet methods to study gravity wave motions and extract vertical characteristics (wavelength, phase speed) versus time and height in the middle atmosphere (30-60 km height) from vertical temperature perturbation profiles provided by a Rayleigh lidar. Different dominant quasi-monochromatic structures with downward phase progression inferior to 1 m/s are identified and extracted to be studied separately. Wave dissipation is observed in the stratopause with production of short waves less than 2 km at the boundary of the lower mesosphere. Longer waves have smaller phase speed than shorter waves