Propagation and interaction of interplanetary transient disturbances. Numerical simulations
Por:
González-Esparza J.A., Jeyakumar S.
Publicada:
1 ene 2007
Resumen:
We study the heliocentric evolution of ICME-like disturbances and their associated transient forward shocks (TFSs) propagating in the interplanetary (IP) medium comparing the solutions of a hydrodynamic (HD) and magnetohydrodynamic (MHD) models using the ZEUS-3D code [Stone, J.M., Norman, M.L., 1992. Zeus-2d: a radiation magnetohydrodynamics code for astrophysical flows in two space dimensions. i - the hydrodynamic algorithms and tests. Astrophysical Journal Supplement Series 80, 753-790]. The simulations show that when a fast ICME and its associated IP shock propagate in the inner heliosphere they have an initial phase of about quasi-constant propagation speed (small deceleration) followed, after a critical distance (deflection point), by an exponential deceleration. By combining white light coronograph and interplanetary scintillation (IPS) measurements of ICMEs propagating within 1 AU [Manoharan, P.K., 2005. Evolution of coronal mass ejections in the inner heliosphere: a study using white-light and scintillation images. Solar Physics 235 (1-2), 345-368], such a critical distance and deceleration has already been inferred observationally. In addition, we also address the interaction between two ICME-like disturbances: a fast ICME 2 overtaking a previously launched slower ICME 1. After interaction, the leading ICME 1 accelerates and the tracking ICME 2 decelerates and both ICMEs tend to arrive at 1 AU having similar speeds. The 2-D HD and MHD models show similar qualitative results for the evolution and interaction of these disturbances in the IP medium. © 2007.
Filiaciones:
González-Esparza J.A.:
Inst. de Geofisica, Universidad Nacional Autonoma de Mexico, Mexico DF 04510, Mexico
Jeyakumar S.:
Inst. de Geofisica, Universidad Nacional Autonoma de Mexico, Mexico DF 04510, Mexico
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