Nightside detached auroras due to precipitating protons/ions during intense magnetic storms
Nightside detached auroras due to precipitating protons/ions during intense magnetic storms
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DOI：
10.1029/2004ja010498
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发表时间：
2005-02
影响因子：
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通讯作者：
Yongliang Zhang;L. Paxton;D. Morrison;B. Wolven;H. Kil;S. Wing
中科院分区：
文献类型：
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作者：
Yongliang Zhang;L. Paxton;D. Morrison;B. Wolven;H. Kil;S. Wing
[1]利用热层-电离层-中间层能量学和动力学（TIMED）/全球紫外成像仪（GUVI）、磁顶-极光全球探测成像仪（IMAGE）/FUV的FUV图像资料和DMSP/SSJ/4仪器的粒子数据，对强磁暴期间的夜侧分离极光（NDA）进行了研究。我们发现NDA仅由质子/离子沉淀引起。薄弧形NDA很可能是由于软（<1 keV）质子/离子沉淀。厚或补丁形的NDA是由高能（10 keV）质子/离子沉淀。所有的情况表明，当Dst小于-130 nT时，观察到NDA。更具体地说，NDA发生在恢复期间或每次强烈风暴的最低Dst期间。NDA的磁纬度在45°和55°之间（L壳层：2.0-3.0）。我们发现NDA的纬度位置与Dst呈准线性相关。NDA的磁本地时间（MLT）范围为1930至0300。所有的事实表明，NDA的来源是环电流中捕获的质子/离子。被捕获的质子/离子的沉淀是由垂直加热的环电流粒子与等离子体层顶处的冷/致密等离子体之间的相互作用引起的。
[1] Nightside detached auroras (NDA) during intense magnetic storms are studied by using FUV image data from Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED)/Global Ultraviolet Imager (GUVI), Imager for Magnetopause-to-Aurora Global Exploration (IMAGE)/FUV, and particle data from DMSP/SSJ/4 instruments. We found that NDA are caused by proton/ion precipitation only. Thin arc-shaped NDA are very likely due to soft (<1 keV) proton/ion precipitation. Thick or patch-shaped NDA are caused by energetic (∼10 keV) proton/ion precipitation. All the cases indicate that the NDA were observed when Dst was less −130 nT. More specifically, the NDA occurred during recovery or the lowest Dst period for each intense storm. The magnetic latitudes of the NDA are between 45° and 55° (L shell: 2.0–3.0). We found that the latitude location of the NDA is quasi-linearly correlated with Dst. The magnetic local time (MLT) of the NDA ranges from 1930 to 0300. All the facts indicate that the source of the NDA is the trapped protons/ions in the ring current. Precipitation of the trapped protons/ions is caused by an interaction between the perpendicularly heated ring current particles and the cold/dense plasma at the plasmapause.