Satellite observations of middlescale acoustic gravity waves above the polar caps
|1Fedorenko, AK |
1Space Research Institute of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, Kyiv, Ukraine
|Kosm. nauka tehnol. 2008, 14 ;(5):065-073|
|Publication Language: Russian|
Wavelike disturbances over the polar caps are analyzed using the Dynamic Explorer 2 satellite data. Some variations of neutral atmosphere parameters with horizontal scale lengths of about several hundred kilometers were systematically detected at altitudes from 250 to 450 km in the polar cap regions. Our analysis of amplitude and phase correlation between different atmosphere gases variations shows that these variations are generated by the propagation of acoustic gravity waves (AGW). We propose a procedure for the separation of AGW perturbations from low-frequency trends of atmosphere parameters on the basis of the cross-correlations analysis of N2 and О variations. The relative AGW amplitudes in the polar regions are equal to 3–10 %, horizontal wavelengths are 500–600 km, periods are equal to tens of minutes. In the daytime region the area of high-wave activity is restricted by high latitudes but in the nighttime sector AGW usually propagate from the polar regions to mid and low latitudes.
|Keywords: amplitude and phase correlation, gravity waves, variations|
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