Simultaneous observations of the ionospheric footprint of flux transfer events and dispersed ion signatures
Simultaneous observations of the ionospheric footprint of flux transfer events and dispersed ion signatures
复制标题
同时观测通量传输事件和分散离子特征的电离层足迹
DOI：
10.5194/angeo-20-281-2002
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发表时间：
2002
影响因子：
1.9
通讯作者：
H. Khan
中科院分区：
文献类型：
--
作者：
G. Provan;S. E. Milan;Mark Lester;T. Yeoman;H. Khan
摘要。我们对DMSP F11和F13航天器的立交桥与Hankasalmi HF相干散射视场的有利结合进行了案例研究。当时，脉冲电离层流（脉冲电离层流）在雷达视场中清晰地观察到高纬度。pif与中等光谱宽度值相关，并被确定为脉冲日侧重联的化石特征。同时，来自两个航天器的DMSP光谱图显示了分散的离子特征，观察到PIF的赤道特征。我们确定了白天侧高纬度磁层边界；这些边界与JHU/APL极光粒子网站上使用算法定义的边界非常吻合（Haerendel et al., 1978； Newell and孟，1988,1995;Newell et al., 1991a, 1991b, 1991c; Traver et al., 1991）。我们得出结论，在这个案例研究中，分散的离子特征映射到非常新开放的通量区域。只有当这种通量向极方向对流时，高频雷达才能观测到中等谱宽的pif的特征。这些特殊的PIF特征映射到地幔降水区域，即最近重新连接的通量。关键字。电离层（电离层-磁层相互作用）。磁层物理学（磁层顶、磁尖和边界层；等离子体对流）
Abstract. We perform a case study of a favourable conjunction of overpasses of the DMSP F11 and F13 spacecraft with the field of view of the Hankasalmi HF coherent scatter. At the time, pulsed ionospheric flows (PIFs) were clearly observed at a high-latitude in the radar field of view. The PIFs were associated with medium spectral width values and were identified as the fossilized signatures of pulsed dayside reconnection. Simultaneously, DMSP spectrograms from the two spacecraft showed dispersed ion signatures, observed equatorwards of the PIF signatures. We identified dayside high-latitude magnetosphere boundaries; these boundaries agreed well with those defined using the algorithm on the JHU/APL auroral particle website (Haerendel et al., 1978; Newell and Meng, 1988, 1995; Newell et al., 1991a, 1991b, 1991c; Traver et al., 1991). We conclude that in this case study the dispersed ion signatures map to regions of very newly-opened flux. It is only when this flux has convected polewards that the signatures of the PIFs with medium spectral widths are observed by the HF radars. These particular PIF signatures map to regions of mantle precipitation, i.e. recently reconnected flux. Key words. Ionosphere (ionosphere-magnetosphere interaction) – Magnetospheric physics (magnetopause, cusp and boundary layers; plasma convection)