STATISTIC STUDY ON ASYMMETRIC PROPAGATION OF FLARE-ASSOCIATED INTERPLANETARY SHOCK WAVES
WEI FENGSI (Institute of Space Physics, Academia Sinica, Beiiing)
On the basis of the comprehensive studies of solar flare-associated geophysical effects (geomagnetic disturbances and the Forbush decreases of cosmic rays), multi-spacecraft observations of solar wind and interplanetary scintillation (IPS) observations, we have furthered our knowledge of the flare-shock wave propagation in the interplanetary space. The main results are that the flare-shock wave is usually an asymmetric propagation related to the flare normal, the direction of the fastest propagation velocity in longitudes tends to deflect towards the interplanetary spiral magnetic field and that in latitudes approaches heliospheric, current sheet, the dynamic parameters (V, P, N, T, β, etc.) and the. shock wave energy. E, are higher in the southeast than in the northwest of the flare shock wave, and conversely, the magnetic field is weaker in the southeast than in the northwest. Based on the results, we proposed a 3-dimensional asymmetrical model of flare-shock wave propagationst. This model is consistent with recent statistical studies obtained by analysing a great deal of spacecraft observation data, and may naturally explain the asymmetric distribution of geomagnetical effects in company with the parent flare positions. The results of this paper could help develop the propagation theory of shock waves and the prediction of the solar-terrestrial disturbance events.