The Link Between Wedge‐Like and Nose‐Like Ion Spectral Structures in the Inner Magnetosphere

Abstract

AbstractThe wedge‐like and nose‐like ion spectral structures, named after their characteristic shapes in the energy‐time spectrograms, appear to be distinctively different structures in the Earth's inner magnetosphere. Here. we present a case study with conjugate observations from the Arase spacecraft and the twin Van Allen Probes on July 1 and 2, 2017, which displayed the characteristic signatures of the wedge‐like and nose‐like ion structures, respectively. When the spacecraft nearly intersected at L = 2.8, the two structures overlapped with enhanced ion fluxes in the energy range of 1–10 keV. These observations suggest that the wedge‐like and nose‐like spectral signatures are merely the manifestations of one single structure along different spacecraft trajectories. This finding is further validated by the reproduction of both structures from a particle‐tracing model, which also indicates their formation processes associated with the intermittent substorm injections in the nightside magnetosphere.