Ionospheric effects of the March 29, 2006, solar eclipse over Kazakhstan

The results of studying the ionospheric effects of the March 29, 2006, solar eclipse are presented. The results were obtained in measurements of local electron density (ED) at Alma-Ata vertical ionospheric sounding station and total electron content (TEC) at the Central Asia network of two-frequency receivers of the GPS navigation system. The ED decrease at the F-layer maximum reached approximately 28%, the delay of the minimum value of EC relative to the moment of the eclipse maximum phase was about 11 min, the relaxation time was 4 min, and the duration of the EC depression at the 0.5 level was 45 min. Dynamic interlayer formations were observed in the ionosphere near the eclipse maximum phase. A traveling ionospheric disturbance, probably generated at the shock wave front during the supersonic motion of the Moon's shadow, was detected. The disturbance period and the horizontal projection of the velocity were about 90 degrees min and similar to 680 m/s, respectively. The wave vector azimuth (145) coincides with the model value of the normal to the shock front.