Abstract
We have investigated some linear as well as nonlinear properties of ion-acoustic wave (IAW) propagation in a non-uniform two-electron-temperature magnetoplasma in the presence of ion-sheared flows. In the linear limit, new dispersion relation has been derived and analyzed in some interesting limiting cases. It is shown that ion-sheared flow can drive the IAW unstable under a certain limit.Whereas, in the nonlinear case, dipolar and vortex street type solutions can appear. It is observed that by choosing some typical parameters of Earth's auroral region, the scalelength of the nonlinear structures are significantly modified. The present investigation might be very useful to explain various types of nonlinear structure formation which has been observed in space environments where two-electron-temperature plasma exist.