Variations of Ionospheric Parameters During the Total Solar Eclipse on 22 July 2009

The variations of ionospheric parameters including fmin, f0F2 and TEC during the total solar eclipse of 22 July 2009 are investigated. The results show that the fmin drops quickly after the eclipse commencement and then gradually restores to the normal value. The f0F2 and TEC decrease greatly during the eclipse maximum. These phenomena are probably caused by the fact that the solar electromagnetic radiation decrease sharply during the solar eclipse. The f0F2 and TEC show some positive disturbance which is more notable near to the equatorial abnormal crest region on about 5~6 hours and some negative disturbance on about 9~10 hours after this eclipse. Combining the analysis of the solar and geomagnetic activity, we think that it seems difficult to further investigate the eclipse ionospheric effect since the space weather events including magnetic storm and electric field penetration are accompanying this event.