Correlative studies of the mesospheric sodium layer at Urbana

Correlative measurements of the mesospheric sodium layer were performed during January 18-19, March 14-15 and March 21-22, 1980 using the Urbana meteor radar and sodium lidar systems. The results show good agreement between the altitude of maximum sodium density and the altitude of the zero wind node, supporting the theory of the wind shear mechanism for the downward sweeping of ionization. Also, reconstruction of the neutral atmosphere density profile from meteor winds exhibit similar features with the small scale fluctuations apparent in the sodium data. It is suggested that the sodium layer is acting as a tracer for gravity wave motions.