Solar energetic particle drifts in the Parker spiral
Solar energetic particle drifts in the Parker spiral
复制标题
太阳高能粒子在帕克螺旋中漂移
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
Timo Laitinen
中科院分区：
文献类型：
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作者：
S. Dalla;Michael Marsh;J. Kelly;Timo Laitinen
帕克螺旋行星际磁场中的漂移被认为是银河宇宙线传播的重要组成部分，而它们被认为是太阳高能粒子（SEP）的可忽略不计。因此，到目前为止，他们一直被忽视的SEP传播建模和数据分析。我们在轴平行于磁场的局部坐标系中，在单粒子一阶绝热理论内研究了帕克螺旋中的漂移速度。我们表明，在行星际空间中存在散射时，SEP能量范围高端的质子经历了显着的梯度和曲率漂移。在无散射的情况下，存在由于磁场曲率引起的漂移。漂移速度的大小在高日面纬度比在黄道附近增加了一个数量级以上;它与太阳的径向距离r有很强的依赖性，在低日面纬度r = 1 Au时达到最大值，在高日面纬度r = 10 Au时达到最大值。由于漂移速度的质量对电荷的依赖性，部分电离SEP重离子的漂移效应比质子强。因此，漂移可能是高能SEP跨场传输的重要来源。
Drifts in the Parker spiral interplanetary magnetic field are known to be an important component in the propagation of galactic cosmic rays, while they are thought to be negligible for solar energetic particles (SEPs). As a result, they have so far been ignored in SEP propagation modeling and data analysis. We examine drift velocities in the Parker spiral within single particle first‐order adiabatic theory, in a local coordinate system with an axis parallel to the magnetic field. We show that, in the presence of scattering in interplanetary space, protons at the high end of the SEP energy range experience significant gradient and curvature drift. In the scatter‐free case, drift due to magnetic field curvature is present. The magnitude of drift velocity increases by more than an order of magnitude at high heliographic latitudes compared to near the ecliptic; it has a strong dependence on radial distance r from the Sun, reaching a maximum at r∼1 AU at low heliolatitudes and r∼10 AU at high heliolatitudes. Due to the mass over charge dependence of drift velocities, the effect of drift for partially ionized SEP heavy ions is stronger than for protons. Drift is therefore likely to be a considerable source of cross‐field transport for high‐energy SEPs.