Long-Period Oscillations in the Meteor Region

Abstract

Meteor wind data taken over Atlanta (34°N, 84°W) during the three-year interval 1974?77 are analyzed for periodic fluctuations of a recurrent nature. Power spectra and cross spectra of the zonal and meridional velocities between 80 and 100 km are constructed for several samples. Ensemble statistics indicate the regular appearance of periods near 17, 8, 5, 2, 1.6 and 1.2 days. Most of these display smaller spectral values near 90 km. The general seasonal behavior has maximum values in winter and minimum values in summer, paralleling the observed variation of traveling wave energy flux in the stratosphere. The regularity with which these oscillations appear, tempts an association with the periods of atmospheric normal modes.