A new approach for magnetospheric substorms

In a previous report we had started a systematic study of the ballooning mo des as the natural waves of the magnetospheric turbulence substorm and reco nnection. After many new results following from the very high mirror ratio of the magnetospheric plasma, summarized in this note, we explain the funda mental vole of ion cyclotron instabilities generated by the closure of conf inement currents, by field-aligned currents in a three-dimensional (3D) con figurations resulting from the growth phase and (or) ballooning modes. Thes e instabilities destroy the current system, dipolarize the magnetic field a nd ave consequently the non linear missing piece of substorm phenomenology. An indirect proof of this theory (apart fi om observational evidence) is f ound in the fast heating of electrons, the so-called 'dispersionless inject ion' and a smaller effect on the proton population (diffusion coefficients are in the minutes time scale for protons and seconds for electrons!). This magnetospheric mechanism is very likely operating in solar flares and is i n fact an added stone to a 3D time-dependent reconnection and acceleration. (C) 2000 Academie des sciences/Editions scientifiques et medicales Elsevie r SAS.