Interhemispheric observations of nightside ionospheric electric fields in response to IMF Bz and By changes and substorm pseudobreakup
Interhemispheric observations of nightside ionospheric electric fields in response to IMF Bz and By changes and substorm pseudobreakup
复制标题
响应 IMF Bz 和 By 变化以及亚暴赝破碎的夜侧电离层电场的半球观测
DOI：
10.1007/s00585-000-0897-x
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发表时间：
2000
影响因子：
1.9
通讯作者：
J. Ruohoniemi
中科院分区：
文献类型：
--
作者：
T. Yeoman;R. V. Lewis;H. Khan;S. W. H. Cowley;J. Ruohoniemi
高频雷达数据在春分，小IMFBy条件下，使电离层对流在亚暴增长阶段和亚暴伪分裂研究在两个半球。这揭示了共轭和非共轭的对流行为在亚暴增长阶段之前和之后的伪破裂发病。的夜侧对流模式被发现迅速响应南转向行星际磁场（IMF）的影响，由于在IMF的倾斜相锋的磁层的黄昏侧翼的案例研究。随后的半球间观测的夜面对流控制的IMFBypolarity。IMFBy分量的变化的响应的时间尺度被发现是一个稍长比forBz，和IMFBy的全面影响是不明显的，在夜侧对流，直到亚暴pseudoblastation已经发生。pseudoblutation本身被发现在两个半球的电离层电场中的一个短暂的抑制。这种气流抑制与高频雷达观测到的亚暴完全爆发非常相似，只是没有随后的向极扩展.关键词：电离层（极光电离层）-磁层物理（磁层-电离层相互作用;风暴和亚暴）
HF radar data during equinoctial, small IMFByconditions have enabled the ionospheric convection during the substorm growth phase and substorm pseudobreakup to be studied in both hemispheres. This has revealed both conjugate and non-conjugate convection behaviour during the substorm growth phase before and after the pseudobreakup onset. The nightside convection pattern is found to respond promptly to the southward turning of the interplanetary magnetic field (IMF) which impacts on the dusk flank of the magnetosphere due to an inclined phase front in the IMF in the case study presented. The subsequent interhemispheric observations of nightside convection are controlled by the IMFBypolarity. The time scale for the response to changes in the IMFBycomponent is found to be a little longer than forBz, and the full impact of the IMFByis not apparent in the nightside convection until after substorm pseudobreakup has occurred. The pseudobreakup itself is found to result in a transitory suppression in the ionospheric electric field in both hemispheres. This flow suppression is very similar to that observed in HF radar observations of full substorm onset, with the exception of a lack of subsequent poleward expansion.Key words:Ionosphere (auroral ionosphere) - Magnetospheric physics (magnetosphere-ionosphere interactions; storms and substorms)