EVIDENCE FOR SPECULARLY REFLECTED IONS UPSTREAM FROM THE QUASI-PARALLEL BOW SHOCK
EVIDENCE FOR SPECULARLY REFLECTED IONS UPSTREAM FROM THE QUASI-PARALLEL BOW SHOCK
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DOI：
10.1029/gl009i012p01333
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发表时间：
1982-01-01
影响因子：
5.2
通讯作者：
SCKOPKE, N
中科院分区：
文献类型：
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作者：
GOSLING, JT;THOMSEN, MF;SCKOPKE, N
使用 ISEE-1 和 ‐2 上的洛斯阿拉莫斯/加兴仪器观察到，沿着螺旋路径行进的旋转粒子束形式的离子速度分布从地球弓激波的准平行部分立即向太阳移动。这些分布的特征表明它们是由部分入射太阳风离子冲击时的近镜面反射产生的。特别是，旋转离子的引导中心运动和陀螺速度在数量上与镜面反射的简单几何考虑一致。这些考虑表明，当 θBn< 45° 时，镜面反射离子可以向上游逃逸，但当 θBn> 45° 时则不能（其中 θB 是上游磁场 B 与局部激波法线 之间的角度）。这些上游旋转离子是太阳风流能量在冲击时消散成其他形式能量的过程之一的重要特征。
Ion velocity distributions in the form of bunches of gyrating particles traveling along helical paths have been observed moving sunward immediately upstream from quasi‐parallel parts of the earth's bow shock using Los Alamos/Garching instruments on ISEE‐1 and ‐2. These distributions have characteristics which indicate that they are produced by the nearly specular reflection at the shock of a portion of the incident solar wind ions. In particular, the guiding center motion and the gyrospeeds of the gyrating ions are quantitatively consistent with simple geometrical considerations for specular reflection. These considerations reveal that specularly reflected ions can escape upstream for θBn< 45° but not for θBn> 45° (where θBnis the angle between the upstream magnetic field, B, and the local shock normal ). These upstream gyrating ions are an important signature of one of the processes by which solar wind streaming energy is dissipated into other forms of energy at the shock.