  The origin of the solitary waves in the Earth's magnetosphere and the solar
wind, particularly close to the magnetic reconnection regions, is still an open
question. For that purpose, we used the fluid model to obtain the mechanism
behind the formation of solitary waves in space plasmas with a variety of
components. Our findings reveal that at the separatrix of the magnetic
reconnection in the Earth's magnetotail, the counter-ejected electron beam
leads to a broadening of the pulse amplitude. While increasing the electron
beam positive velocity causes a bit increase in the soliton amplitude.
Moreover, we observed that the soliton profile is very sensitive to the plasma
parameters like density and temperature. The calculated electric field using
the current model and the measured electric field in the Earth's magnetosphere
and solar wind is highlighted.
