Storm enhanced density: magnetic conjugacy effects
Storm enhanced density: magnetic conjugacy effects
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DOI：
10.5194/angeo-25-1791-2007
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发表时间：
2007-08
影响因子：
1.9
通讯作者：
J. Foster;W. Rideout
中科院分区：
文献类型：
--
作者：
J. Foster;W. Rideout
抽象。在磁暴的早期阶段，低纬和中纬电离层受到很大的扰动。大的SAPS电场从扰动环电流向地球映射，重叠和侵蚀外等离子体层和中纬度电离层，绘制出扩展的风暴增强密度（SED）羽流。我们使用卫星和地面观测相结合的程度磁共轭与特定功能的风暴电离层扰动。我们发现，许多电离层扰动的功能表现出一定程度的磁共轭和磁共轭的电场的运作。TEC增强的内磁层磁力线在底部的SED羽表现出本地化的和依赖的功能，这不是严格的磁共轭。从这些源区流出的SED羽流密切遵循磁共轭路径。SED羽流可用作干扰电场位置和强度的示踪剂。来自低纬度的冷等离子体的SED流在中午时分进入极冠，在极地地区形成共轭电离舌。SED羽流表现出密切的磁共轭，证实SED是一个对流电场占主导地位的效果。结果表明：（1）SED羽流发生在南北半球的磁共轭区; 2)SED羽流的尖锐极向边缘的位置是紧密共轭的。3)在磁共轭区域（SAPS通道）中观察到SAPS电场。4)强TEC增强的基础上的SED羽在北美部门是更广泛的比在其磁共轭区。5)SED羽流在接近中午时进入极冠，形成了电离极舌（TOI），在两个半球的磁共轭区域都可以看到。
Abstract. In the early phases of a geomagnetic storm, the low and mid-latitude ionosphere are greatly perturbed. Large SAPS electric fields map earthward from the perturbed ring current overlapping and eroding the outer plasmasphere and mid-latitude ionosphere, drawing out extended plumes of storm enhanced density (SED). We use combined satellite and ground-based observations to investigate the degree of magnetic conjugacy associated with specific features of the stormtime ionospheric perturbation. We find that many ionospheric disturbance features exhibit degrees of magnetic conjugacy and simultaneity which implicate the workings of electric fields. TEC enhancements on inner-magnetospheric field lines at the base of the SED plumes exhibit localized and longitude-dependent features which are not strictly magnetic conjugate. The SED plumes streaming away from these source regions closely follow magnetic conjugate paths. SED plumes can be used as a tracer of the location and strength of disturbance electric fields. The SED streams of cold plasma from lower latitudes enter the polar caps near noon, forming conjugate tongues of ionization over the polar regions. SED plumes exhibit close magnetic conjugacy, confirming that SED is a convection electric field dominated effect. Several conclusions are reached: 1) The SED plume occurs in magnetically-conjugate regions in both hemispheres. 2) The position of the sharp poleward edge of the SED plume is closely conjugate. 3) The SAPS electric field is observed in magnetically conjugate regions (SAPS channel). 4) The strong TEC enhancement at the base of the SED plume in the north American sector is more extensive than in its magnetic conjugate region. 5) The entry of the SED plume into the polar cap near noon, forming the polar tongue of ionization (TOI), is seen in both hemispheres in magnetically-conjugate regions.