Dynamics Explorer Measurements of Particles, Fields, and Plasma Drifts Over a Horse- Collar Auroral Pattern
Dynamics Explorer Measurements of Particles, Fields, and Plasma Drifts Over a Horse- Collar Auroral Pattern
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Dynamics Explorer 对马领极光图案上的粒子、场和等离子体漂移的测量
DOI：
10.5636/jgg.44.1225
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
J. Birn
中科院分区：
文献类型：
--
作者：
J. Sharber;E. W. Hones;R. Heelis;J. Craven;L. Frank;N. Maynard;J. Slavin;J. Birn
如地面测量和星载成像仪所示，平静（通常是向北的IMF）间隔的一种全球极光模式特征是收缩但增厚的发射区，其中黎明和黄昏部分可以向极向高纬度扩散。由于其形状，这种图案被称为“马领”极光（HONES等人，1989年）。在这份报告中，我们使用的动力学探测器的数据集来检查的情况下，这种“马项圈”模式观察到的DE-1极光成像仪，而在同一时间DE-2，在较低的高度，测量沉淀粒子，电场和磁场，等离子体漂移。我们的分析表明，在一般情况下，有密切的协议之间的光学签名和粒子沉淀模式。在许多情况下，在几十到几百公里的尺度上，在等离子体流梯度为负的地方观察到电子沉淀特征和向上的场向电流。粒子，等离子体，并沿沿着的卫星轨道和2-D的角度的成像仪进行现场测量提供了一种手段，确定在此期间的北IMF的高纬度电离层对流的配置。最近的绘图研究被用来将低空观测与可能的磁层源区联系起来。
As shown from ground-based measurements and satellite-borne imagers, one type of global auroral pattern characteristic of quiet (usually northward IMF) intervals is that of a contracted but thickened emission region in which the dawn and dusk portions can spread poleward to very high latitudes. Because of its shape, such a pattern has been referred to as a “horse-collar” aurora (HONES et al., 1989). In this report we use the Dynamics Explorer data set to examine a case in which this “horse-collar” pattern was observed by the DE-1 auroral imager while at the same time DE-2, at lower altitude, measured precipitating particles, electric and magnetic fields, and plasma drifts. Our analysis shows that in general there is close agreement between the optical signatures and the particle precipitation patterns. In many instances, over scales ranging from tens to a few hundred kilometers, electron precipitation features and upward field-aligned currents are observed at locations where the plasma flow gradients indicate negative ∇·E. The particle, plasma, and field measurements made along the satellite track and the 2-D perspective of the imager provide a means of determining the configuration of convective flows in the high-latitude ionosphere during this interval of northward IMF. Recent mapping studies are used to relate the low-altitude observations to possible magnetospheric source regions.