Total electron content variations during the strong typhoon 5-11 August 2006 near south-eastern coast of China

摘要

The analysis of total electron content (TEC) variations as deduced from GPS data of 11 sites in the region (5°S - 80°N; 110 - 160°E) during 2-15 August 2006 was carried out to find possible ionospheric effects of the strong typhoon SAOMAI (5-11 August 2006) near south-eastern coast of China. For this purpose we used also Global Ionospheric Maps (GIM).The intensification of TEC variations in the time period range 32-128 min for evening local time was found in the region of the typhoon activity during magnetic storm of August 7, 2006. However this effect more likely was caused by dynamics of the equatorial anomaly irregularities as well as by disturbed geomagnetic situation (Kp was up to 5-6, Dst varied from -74 to -153 nT).The analysis of absolute TEC diurnal variations and TEC variations in the time period range 2-25 min didn't show evident change of spectrum of TEC variations during typhoon in comparison with neighbor days. Therefore we didn't find ionospheric disturbances that were caused by typhoon SAOMAI. Perhaps the ionospheric typhoon effects were too weak to be picked out from background ionospheric variations using TEC measurements.