The striation model describes the evolution of plasma clouds along and across the geomagnetic field B in the earth ionosphere. The plasma clouds drift across the ionosphere in the presence of an ambient electric field and a neutral wind. In this article we introduce new techniques to extend the simulation tools to the earth magnetic field geometry. The model moreover allows a three-dimensional representation of the plasma density evolution. The derivation of this model is recalled in the context of a non-uniform magnetic field and involves a new set of local coordinates. A numerical scheme is proposed to solve the resulting system of nonlinear partial differential equations. Numerical simulations are realized and the striation of the initial plasma cloud into a cluster of smaller clouds is obtained. The present work allows the observation of the structures along the magnetic field lines.