Theoretical and Applied Physics

Atmospheric and Magnetospheric Sciences

The interaction of the supersonic solar wind with the Earth’s dipole magnetic field is surprisingly complicated. About 5 orders of magnitude of spatial scales are involved in the global behaviour of the magnetospheric system and timescales from seconds for the auroral pulsations to several minutes for the reaction of the global magnetosphere to solar-wind pressure changes to several days for the intensification of the electron radiation belt to years for the decay of relativistic electrons. Plasma-physical length scales vary from a Debye length of 0.4 cm in the ionosphere to ion gyro radii of 1000 km in the magnetotail and in the ion radiation belt; plasma-physical timescales associated with wave substructure can also be very short.