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利用CHAMP卫星磁场测量数据,研究2003年11月超强磁暴期间顶部电离层全球大尺度场向电流分布特征及行星际条件的控制作用.结果表明:(1)磁暴期间场向电流密度比平静期大大增强,昼与夜及冬与夏半球不对称;(2)发现沿纬度积分的场向电流密度主要受太阳风动力学压强而不是行星际磁场的控制;(3)磁暴期间场向电流低纬边界向赤道扩展,最低可达45°MLat;向阳侧此扩展直接受南向行星际磁场Bz的控制,相应的行星际-磁层-电离层作用时间尺度约25min;当南向IMFBz小于?30nT时,场向电流朝赤道的扩展出现非线性饱和;而在背阳侧,这一扩展及恢复,比行星际参数的变化滞后约3h,但与表征磁层环电流的Sym-H指数几乎同步变化;(4)磁暴主相期间,背阳侧强场向电流纬度分布范围达25°以上,并出现多达10片以上的多电流片结构.
Using the data of CHAMP satellite magnetic field measurements, the global large-scale field current distribution and control of interplanetary conditions in the top ionosphere during the super-strong storms in November 2003 are studied.The results show that: (1) during field storms, the field current density is higher than the quiescent period (2) It is found that the field current density along the integral of latitude is mainly controlled by the solar wind dynamic pressure rather than the control of the interplanetary magnetic field; (3) During the magnetic storms the field current is low at the latitude The boundary extends to the equator with a minimum of 45 ° MLat. The extension on the sunny side is directly controlled by the southward interplanetary magnetic field Bz. The corresponding interplanetary-magnetospheric-ionospheric interaction time scale is about 25 minutes. When the southbound IMFBz is less than 30 nT , The field current nonlinear expansion toward the equator appears nonlinearly. On the dusk side, this expansion and recovery lags behind the change of the interplanetary parameters by about 3 h, but almost agrees with the Sym-H index characterizing the magnetospheric current (4) During the main phase of magnetic storm, the latitudinal distribution of the strong field current on the dorsal gyrus reaches more than 25 ° and there are as many as 10 multi-current slices.