Multipoint observation of the response of the magnetosphere and ionosphere related to the sudden impulse event on 19 November 2007

Abstract

The aim of this study is to provide a complete scope of a magnetic sudden impulse (SI) event along its way through interplanetary space and the magnetosphere until its arrival to the ground. In our case, we chose the event of 19th November 2007 because of the availability of enough well-located spacecraft at that moment for our purpose. We have used a 16 spacecraft data set. We calculated the mass flux variation and the change in magnetic field components across the discontinuity. Thus, we identified the solar wind discontinuity as a shock. We also calculated the orientation of the solar wind shock front. Then, we examined the effects of the shock front propagation in detail. With this large data set, we obtained a global view of the travelling wave front and identified the effects of the compressional wave front. Thus, we determined in detail the shock front passing through the different parts of the magnetosphere. We described the compressional effects in the bow shock, the magnetosheath, and the magnetopause and we depicted the propagation inside the inner magnetosphere. Moreover, we used an extensive data set from magnetic observatories on the ground and so we studied the global distribution of the SI waveform. Finally, the comparison of the observational facts with those derived from the theoretical model showed a good consistency. On the basis of the waveforms and polarizations of this SI, we determined the location in latitude where ionospheric currents (ICs) changed their sense. And also, we related polarization at ground to polarization measured by GOES spacecraft.