Chunchuzov I.,Obukhov Institute of Atmospheric Physics Moscow Russia |
Kulichkov S.,Obukhov Institute of Atmospheric Physics Moscow Russia |
Perepelkin V.,Obukhov Institute of Atmospheric Physics Moscow Russia |
Popov O.,Obukhov Institute of Atmospheric Physics Moscow Russia |
And 2 more authors.
Journal of Geophysical Research: Atmospheres | Year: 2015
The wind velocity structure in the upper stratosphere, mesosphere, and lower thermosphere (MLT) is studied with the recently developed method of infrasound probing of the atmosphere. The method is based on the effect of infrasound scattering from highly anisotropic wind velocity and temperature inhomogeneities in the middle and upper atmosphere. The scattered infrasound field propagates in the acoustic shadow zones, where it is detected by microbarometers. The vertical profiles of the wind velocity fluctuations in the upper stratosphere (30-52km) and MLT (90-140km) are retrieved from the waveforms and travel times of the infrasound signals generated by explosive sources such as volcanoes and surface explosions. The fine-scale wind-layered structure in these layers was poorly observed until present time by other remote sensing methods, including radars and satellites. It is found that the MLT atmospheric layer (90-102km) can contain extremely high vertical gradients of the wind velocity, up to 10m/s per 100m. The effect of a fine-scale wind velocity structure on the waveforms of infrasound signals is studied. The vertical wave number spectra of the retrieved wind velocity fluctuations are obtained for the upper stratosphere. Despite the difference in the locations of the explosive sources all the obtained spectra show the existence of high vertical wave number spectral tail with a -3 power law decay. The obtained spectral characteristics of the wind fluctuations are necessary for improvement of gravity wave drag parameterizations for numerical weather forecast. © 2015. American Geophysical Union. All Rights Reserved. Source