The low dimensionality of magnetospheric activity indicated by previous phase space reconstructions using the AE and AL data suffer from the limitations of these techniques. In this paper the singular spectrum analysis is used to study the global magnetospheric dynamics using the AE data and it yields a correlation dimension ≃2.5, thus confirming the low dimensionality published earlier. Further, this technique shows that the global magnetospheric dynamics can be described by 3 variables whose dynamical features are obtained from the AE data.