太阳风扰动对极光电急流和环电流指数的影响

利用WIND卫星的太阳风观测数据和地磁活动指数,研究了太阳风扰动对环电流SYM-H指数,西向极光电急流AL指数和东向极光电急流AU指数的影响.结果表明,太阳风动压增长和减少能够同步或延迟引起地磁活动指数的强烈扰动,其包括环电流指数的上升,西向极光电急流指数的下降和东向极光电急流指数的上升.太阳风动压的突然剧烈增加还能够触发超级亚暴和大磁暴.太阳风动压脉冲引起的地磁效应具有复杂的表现形式,这说明太阳风动压脉冲的地磁效应不仅与太阳风动压脉冲大小和持续时间有关,还与磁层本身所处的状态有关.时间尺度较长,消耗能量较大的磁暴只有大的持续时间较长的太阳风动压脉冲才能激发.

Influence of Solar Wind Disturbance on Ring Current and Auroral Electrojet Indexes

Using the data of solar wind recorded by WIND and geomagnetic activity index,we studied the influence of the variation of solar wind dynamical pressure on ring current index SYM-H and auroral electrojet indexes(AU and AL).The increase and decrease of solar wind dynamical pressure can produce simultaneous or delayed disturbances in geomagnetic activity indexes,which include the transient increase of ring current index SYM-H,increase of eastward electrojet index AU and decrease of westward electrojet index AL.The sudden large increase of solar wind dynamical pressure can trigger super substorm and large geomagnetic storm.The response of geomagnetic activity indexes to solar wind dynamical pressure impulse is complicated and various,indicating the geomagnetic effect of solar wind dynamical pressure impulse not only depends on the strength and duration of solar wind dynamical pressure impulse,but also on the state of magnetosphere.Large geomagnetic storm,which last long and consume more energy,can only be triggered by strong and long impulse of solar wind dynamical pressure.