2000年4月6日磁暴期间磁扰变化在低纬子午链的纬度效应

LATITUDINAL EFFECT OF MAGNETIC STORM ON APRIL 6,2000 AT LOW-LATITUDE MERIDIAN CHAIN

利用低纬地磁子午链上H和D分量的分均值数据 ,分析了 2 0 0 0年 4月 6日磁暴期间磁扰变化的纬度效应 .主要特点是 :(1 )急始期间H分量急始跃变幅随磁纬降低而减小 ,且急始变幅的下降率随磁纬降低而逐渐增大 ;(2 )初相期间H分量第 2峰值的变幅和初相持续时间随磁纬降低而减小 ;(3)主相期间H分量迅速减小 ,并随纬度降低最大变幅明显增加 ;(4)恢复相H分量呈两阶段上升趋势 ,前一阶段迅速上升 ,后一阶段上升速度明显减小 .最后对这些磁扰变化的纬度效应与空间电流体系的密切关系作了讨论 .

In this paper the latitudinal effect of geomagnetic disturbances during the geomagnetic storm on April 6,2000 is analyzed by using minutely averages of H and D components at low latitude geomagnetic meridian chain. The main characteristics are as follows. (1) SC range of H component decreases and the decrease rate increases with decreasing latitude. (2) The range of the second peak of H component and the duration of the initial phase decrease with decreasing latitude during the initial phase. (3) H component decreases speedily and the change range increases with during decreasing in the main phase. (4) The increase of H component is divided to two steps in the recovery phase. H component increases quickly and the change range decreases with decreasing latitude in the former step. The increase rate of H component decreases in the later step. Finally, the intimate relationship between the latitudinal effect of the geomagnetic disturbances and the space current system is discussed.