Auroral particle precipitation characterized by the substorm cycle
Auroral particle precipitation characterized by the substorm cycle
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DOI：
10.1002/jgra.50160
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发表时间：
2012-12
期刊：
影响因子：
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通讯作者：
S. Wing;M. Gkioulidou;J. Johnson;P. Newell;Chih‐Ping Wang
中科院分区：
文献类型：
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作者：
S. Wing;M. Gkioulidou;J. Johnson;P. Newell;Chih‐Ping Wang
亚暴释放大量能量，其中一些用于为极地地区的沉淀粒子提供能量。用11年的DMSP SSJ/4/5数据进行叠加历元分析，以表征扩散、单能和宽带/波沉淀电子和沉淀离子的亚暴周期。虽然亚暴只增加了30%的离子压力，但它们分别增加了扩散，单能和波动电子极光的310%，71%和170%。亚暴激发离子极光主要在21：00-05：00磁当地时间（MLT）部门。扩散电子极光的动力学不同于其他两种电子极光。扩展阶段的持续时间约为15分钟的单能和波电子极光，而它是1小时的扩散电子极光。单能和波动电子极光在5 h内完成亚暴循环，而扩散电子极光则需要5 h以上。扩散电子极光的功率和能量通量在亚暴爆发前15 min开始增加，而单能和波动电子极光的功率和能量通量在亚暴爆发前1 h和15 min开始增加。单能电子极光功率和能量通量的增加可能是由于在生长阶段磁尾拉伸和区域1场向电流的增加。单能电子也可能与快速流动有关，这在以前的黄昏-午夜扇区中更频繁地观察到。
Substorms release a large amount of energy, some of which is used to energize the precipitating particles in the polar region. Superposed epoch analysis was performed with 11 years of DMSP SSJ/4/5 data to characterize the substorm cycle of the diffuse, monoenergetic, and broadband/wave precipitating electrons and precipitating ions. Although substorms only increase the ion pressure by 30%, they increase the power of the diffuse, monoenergetic, and wave electron aurora by 310%, 71%, and 170%, respectively. Substorms energize the ion aurora mainly in the 21:00–05:00 magnetic local time (MLT) sector. The dynamics of the diffuse electron aurora are different from those of the other two electron aurorae. The expansion phase duration is approximately 15 min for the monoenergetic and wave electron aurorae, whereas it is 1 h for the diffuse electron aurora. The monoenergetic and wave electron aurorae appear to complete the substorm cycle within a 5 h interval, whereas the diffuse electron aurora takes more than 5 h. The diffuse electron aurora power and energy flux start increasing at 15 min before the substorm onset, whereas those for the monoenergetic and wave electron aurorae start increasing at 1 h and 15 min before the onset. The increase in the monoenergetic electron aurora power and energy flux may result from the increase in the magnetotail stretching and region‐1 field‐aligned current during the growth phase. The monoenergetic electrons may also be associated with fast flows, which have been previously observed more frequently in the dusk‐midnight sector.