Low frequency oscillations of the magnetosphere

Sudden pulses in the model solar wind sets the Earth´s magnetosphere into damped oscillatory motions. A simple model is capable of explaining many of the basic properties of these oscillations, giving scaling laws for their characteristics in terms of the parameters of the problem, such as the Solar wind momentum density. The period of the oscillations, their damping and anharmonic nature are accounted for. The model has no free adjustable numerical parameters and can be seen as an effort to predict some dynamic properties of the magnetosphere on the basis of measurable steady state characteristics. A simple test of the model is found by comparing its prediction of the Earth-magnetopause distance with observed values. The results agree well with satellite observations and also numerical simulations.