We report a special polar rain aurora case around 11:24 UT on October 27, 2003, where intense polar rain electrons produced observable polar rain auroral emission with the shape of a roughly dawn-dusk aligned bar. Associated solar wind speed and density observations during the event were around 450 km/s and 2.5 cm⁻³ respectively. The interplanetary magnetic field (IMF) components B_x, B_y, and B_z were ~5, −3, and 5 nT respectively. The negative B_y condition likely caused the dawnside shift and slight tilt of the polar rain aurora bar. Furthermore, although Kelvin-Helmholtz waves on the high latitude magnetopause have been previously reported to induce dawn-dusk aligned auroral bars (Zhang et al., 2007), the solar wind and IMF conditions of the event are not favorable for generating them (Zhang et al., 2013) and are therefore not a likely cause. Instead, coincident observations by the Geotail satellite show enhanced anti-sunward flux in the solar wind superthermal electrons (7 eV–42 keV) around the time of the auroral bar. The solar wind superthermal electron spatial size, when mapped into the polar ionosphere, is consistent with the width of the auroral bar, confirming a connection between the two.

我们在2003年10月27日美国东部时间11:24左右报告了一个特殊的极雨极光案例，在该案例中，强烈的极雨电子产生了可观察到的极雨极光发射，其形状大致为黎明-黄昏对齐的条形。事件期间的相关太阳风速度和密度观测分别约为450 km / s和2.5 cm ^-3。行星际磁场（IMF）分量B _x，B _y和B _z分别为〜5，-3和5 nT。负B _y这种情况很可能导致极地雨极光条发生了黎明移动和轻微倾斜。此外，尽管先前已经报道过高纬度磁更年期的开尔文-亥姆霍兹波会诱发黎明-黄昏对准的极光条（Zhang等人，2007），但该事件的太阳风和IMF条件不利于产生它们（Zhang等人）。等人，2013年），因此不是可能的原因。取而代之的是，Geotail卫星的同步观测显示，在极光棒时间前后，太阳风超热电子（7 eV–42 keV）的反日向通量得到了增强。当映射到极地电离层时，太阳风的超热电子空间大小与极光棒的宽度一致，从而证实了两者之间的联系。