What high altitude observations tell us about the auroral acceleration: A Cluster/DMSP conjunction
What high altitude observations tell us about the auroral acceleration: A Cluster/DMSP conjunction
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高空观测告诉我们有关极光加速度的信息：星团/DMSP 结合
DOI：
10.1029/2002gl016006
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发表时间：
2003
影响因子：
5.2
通讯作者：
P. Newell
中科院分区：
文献类型：
--
作者：
A. Vaivads;M. André;S. Buchert;A. Eriksson;A. Olsson;J. Wahlund;P. Janhunen;G. Marklund;L. Kistler;C. Mouikis;D. Winningham;A. Fazakerley;P. Newell
利用Cluster卫星和DMSP F14卫星的磁共轭观测，对极光弧的场线进行了研究。星系团位于加速区的上方，观察到向上的keV离子束和双极电结构。集束高度的综合电位呈下降趋势，这与低空的keV电子加速能一致。星团高度向地坡印亭通量与低空电子能量通量相当。因此，对于这一事件，极光加速度可以被描述为具有到达星团高度的等势线的准平稳势结构。弧在等离子体片的外缘以密度梯度形成。多个Cluster卫星测量使我们能够研究与弧的发展相关的密度增加，并估计结构的速度。准电位结构本身可能是alfvsamn波的一部分。
Magnetic conjugate observations by Cluster and DMSP F14 satellites are used to study the field lines of auroral arc. Cluster is well above the acceleration region and observes upward keV ion beams and bipolar electric structures. The integrated potential at Cluster altitudes shows a dip that is consistent with the keV electron acceleration energy at low altitude. The earthward Poynting flux at Cluster altitudes is comparable to the electron energy flux at low altitudes. Thus, for this event the auroral acceleration can be described as a quasi‐stationary potential structure with equipotential lines reaching the Cluster altitudes. The arc forms at the outer edge of the plasma sheet at a density gradient. Multiple Cluster satellite measurements allow us to study the density increase associated with the development of the arc, and to estimate the velocity of the structure. The quasi‐potential structure itself may be part of an Alfvén wave.