赤道电集流扰动变化的多源性

DIFFERENT CAUSES FOR DISTURBED VARIATION OF THE EQUATORIAL ELECTROJET

用１９７９年和１９８５－１９８８年印度３站地磁Ｚ分量资料分析了赤道电集流的扰动变化。按磁层－电离层耦合的程度和发展阶段，得到了４类扰日△Ｚ平均日变化的不同形态，并对此作了谐波分析和相关分析。各类扰日中，电动耦合直接穿透及后继的屏蔽效应和动力耦合包括电离层扰动发电机效应的相对重要性各不相同。有关结果还用中纬地磁指数的变化进行了印证。

Data of geomagnetic Z-component in 1985-1988 and 1979 from three Indian ground stations are used to analyse the disturbed variation of the equatorial electrojet.The disturbed days are classified into 4 types according to disturbed degree and evolution stage of the magnetosphere-ionosphere coupling. Fourier analysis and correlation analysis are used. It is shown that the relative importance of the electrodynamic and dynamic couplings is different for each of the 4 types.The results are confirmed by the variation of middle-latitude geomagnetic index.