Sq等效电流在太阳活动周中的分析研究

Sq电流体系的产生与太阳密切相关,太阳的活动情况会对Sq电流体系造成直接的影响.本文应用1996年至2006年(第23太阳周)INTERMAGNET地磁台网以及中国地震局地球物理研究所国家地磁台网中心的全球地磁场观测数据,通过球谐分析的方法建模,对11年期间每月Sq内外源等效电流体系进行分离,分析Sq内外源等效电流在太阳活动周中的变化情况.结果表明,Sq内外源等效电流强度与太阳黑子的变化具有较高的相关性和一致性,内外源等效电流强度在太阳活动高年期间明显大于其在太阳活动的上升年和下降年期间的强度;Sq内外源等效电流焦点的纬度变化与太阳活动没有显著的一致性;Sq内外源等效电流强度的季节效应在太阳活动的高年和低年具有显著的差别,太阳活动高年期间等效电流强度在分点季节最大,而在其他年份南北半球的等效电流强度都是在各自半球的夏季达到最大.

The study of Sq equivalent current during the solar cycle

The Sq current relates closely to the solar activity, and the solar activities directly affect the Sq current. In this paper, the geomagnetic data from INTERMAGNET and Geomagnetic Network Center of China Earthquake Administration in 23^rd solar cycle (1996—2006) have been used to analyze the variation of external and internal source Sq equivalent current. The method we adopted is the spherical harmonics analysis. The intensity of the Sq equivalent current has a good correlation to the spot number of the sun. The intensity of the current is larger during the solar maximum than that during the solar minimum. The latitude of the current focus is not affected significantly by the solar activities. There is an evident difference between the seasonal change of current intensity during the solar maximum and minimum. During the solar maximum, the peak value of current intensity occurs near the equinoxes, while during the solar minimum years, the peak value of current intensity occurs near the solstices.