We investigate the formation of He⁺ and O⁺ multiple-nose structures observed by the Helium, Oxygen, Proton, and Electron instrument onboard Van Allen Probes A on December 2, 2012. Previous studies have suggested that multiple-nose structures can be formed by changes in the convection electric field. However, the specifics of how these changes can produce multiple-nose structures have been left unresolved. In this study, we simulate ions as they drift from the plasma sheet into the inner magnetosphere and find that the multiple-nose structures were created by the overlap of a nose structure and a spectral gap in the energy-time spectrograms of the measured ion fluxes. Ion drift path tracings show that the spectral gap was produced by an enhancement of the convection electric field several hours before. Furthermore, the simulations reveal new insight of how the timing and location of the local electric field enhancements play a key role in the formation of the observed multiple noses.

我们研究了He ⁺和O ⁺的形成Van Allen Probe A上的氦气，氧气，质子和电子仪器在2012年12月2日观察到多鼻子结构。以前的研究表明，对流电场的变化可以形成多鼻子结构。但是，这些变化如何产生多鼻结构的细节尚未解决。在这项研究中，我们模拟了离子从等离子体薄板漂移到内部磁层的过程，发现多鼻子结构是由鼻子结构的重叠和被测离子通量的能量时间谱图中的谱隙所形成的。离子漂移路径示踪表明，谱隙是在数小时前对流电场增强后产生的。此外，