Two-dimensional simulation of flare-associated disturbances in the solar wind

The propagation of flare-associated disturbances through the interplanetary medium is examined by using numerical solutions of time-dependent two-dimensional hydrodynamic flow in spherical coordinates. The study is limited to blast wave phenomena, and the dependence on initial disturbance energy and angular extent is examined. For constant energy disturbances initially occupying cones of half angle up to ∼15° at 0.1 AU, the angular dependence of the transmit time to 1 AU and of the shock shape at 1 AU is very small. For disturbance energies at 0.1 AU of a few times 1030 ergs, transit times to 1 AU are ∼65 hours. The calculated disturbance shapes at 1 AU and the transit times are found to be in good agreement with the observational data.