The cusp has important effects on the transporta-
tion of particles and their energy from the solar wind to
the magnetosphere, and ionosphere, and high-altitude atmo-
sphere. The cusp can be considered to be a part of the mag-
netospheric boundary layer with weaker magnetic fields. It
has been studied since 1971 by different satellite observa-
tions. Despite many years of investigation, some problems,
such as the boundaries, shapes, and method of construction,
remain to be solved. The double cusp was first reported by
Wing using the observation of the DMSP satellite. He also
compared the results of observations with the results of a
2D MHD simulation. In this study, by performing simula-
tions and analyzing the results, we report the observation of
a V-shaped double-cusp structure under the northward Inter-
planetary Magnetic Field (IMF). In our simulation, the dou-
ble cusp was seen only for electrons, although a weak dou-
ble cusp was observed for ions as well. We showed that this
double cusp occurred because of electron precipitation from
different sources of solar wind and magnetosphere with dif-
ferent magnetic field strengths. In previous studies of the
double cusp, there were debates on its spatial structure or
on its temporal behavior due to the cusp movement caused
by the sharp solar wind effects on the magnetosphere shape.
Here we report the spatial detection of the double cusp simi-
lar to the one observed by the DMSP satellite, but for the
northward IMF case. Also, we investigate the asymmetry
along the dawn-dusk side of the magnetosphere using our
3D PIC simulation code.

EB00000003914K

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• Double-cusp simulation during northward IMF using 3D PIC global code