Intradiurnal wind variations in the lower thermosphere over the Antarctic from meteor radar measurements

Meteor radar data for wind obtained at the Amundsen-Scott station (South Po le) in 1995-1996 and the Molodezhnaya station (68 degrees S) in 1990-1991 a re analyzed with the emphasis on intradiurnal variations common to both sta tions. The strong variability of the observed wave variations is taken into account by using the S-transform, and the times of initiation and lifetime s of these variations are estimated. It is shown that wind variations at th e Molodezhnaya station include periods identical to those characteristic of the South Pole. The wave amplitudes at different latitudes are comparable in magnitude and exceed 15 m/s, the waves propagate to the west, and their periods are close to the theoretical periods of characteristic oscillations of the ideal atmosphere. This is evidence in favor of the suggestion that the waves observed are the atmospheric characteristic modes of the type of Lamb waves.