Generation of transient dayside subauroral proton precipitation
Generation of transient dayside subauroral proton precipitation
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DOI：
10.1029/2004ja010393
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发表时间：
2004-12
影响因子：
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通讯作者：
S. Fuselier;S. Gary;M. Thomsen;E. Claflin;B. Hubert;B. Sandel;T. Immel
中科院分区：
文献类型：
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作者：
S. Fuselier;S. Gary;M. Thomsen;E. Claflin;B. Hubert;B. Sandel;T. Immel
[1]磁层顶-极光全球探测成像仪（IMAGE）航天器获得了质子极光的第一批全球图像。从这些图像中的发现之一是一个区域的质子降水赤道的名义极光椭圆形。这种降水可以在一个大的太阳风压力脉冲之后立即观察到10分钟。已经提出了产生这种沉淀的各种机制。本研究的重点是所提出的机制之一，散射和沉淀的质子，由于与电磁离子回旋（EMIC）波的相互作用。利用IMAGE航天器远紫外和极紫外成像仪的数据、洛斯阿拉莫斯地球同步航天器的现场环电流数据和ACE航天器的现场太阳风数据，解释了降水的两个特征，即当地时间发生和有限的纬度范围。降水的局地时间发生与太阳风中压力脉冲阵面的方向有关。有限的纬度范围内的排放似乎与热环电流质子和冷等离子体层离子，引起EMIC波增长之间的相互作用。
[1] The Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) spacecraft obtained the first global images of the proton aurora. One of the discoveries from these images was a region of proton precipitation equatorward of the nominal auroral oval. This precipitation can be observed for ∼10 min immediately following a large solar wind pressure pulse. Various mechanisms have been proposed for producing this precipitation. This study focuses on one of the proposed mechanisms, the scattering and precipitation of protons due to interaction with electromagnetic ion cyclotron (EMIC) waves. Using data from the IMAGE spacecraft FUV and EUV imagers, in situ ring current data from the Los Alamos geosynchronous spacecraft, and in situ solar wind data from the ACE spacecraft, two features of the precipitation, the local time occurrence and limited latitudinal extent, are explained. The local time occurrence of the precipitation is correlated with the orientation of the pressure pulse front in the solar wind. The limited latitudinal extent of the emissions appears to be related to the interaction between the hot ring current protons and the cold plasmaspheric ions that gives rise to EMIC wave growth.