[P-EM16] Space Plasma Physics: Theory and Simulation

[PEM16-P06] Autonomously Vibrating Magnetosphere generated by Forward and Inverse Karman Vortex and Lobe Reconnection in a Northward Magnetic Field

*DongSheng CAI¹ (1.University of Tsukuba)

Keywords:forward and inverse Karman vortex street, autonomous magnetoshere , lobe reconnection

Several papers discussed Kelvin-Helmholtz (K-H) instability and its related waves and vortexes using global 2D/3D MHD simulations [Guo et al., 2010; Li et al., 2012; Li et al., 2013; Merkin et al., 2013]. They find a double-vortex sheet in which a vortex train propagates along the inner and outer edges of the magnetopause both in dawn and dusk, which is so-called a forward Karman vortex street. In the forward Karman vortex street, the paired and staggered two vortexes face each other in counterclockwise and generate a dragging flow. Those vortex trains in the inner and outer edges continues to north and south into ionospheres to form the ionospheric Karman vortex street. However, those two inner vortex trains, respectively, from the dawn and dusk sides of the magnetosphere near the equator plain face each other in clockwise and generate a propulsion flow crossing the pole. This vortex street system is so-called an inverse Karman vortex street. The propulsion flow is generated by the lobe reconnection. Global magnetospheric coherent structures related to the dynamical coupling between the dayside magnetopause frontier and ionosphere in a northward IMF configuration are analyzed using the concept of forward and inverse Karman vortex street in a global 3D MHD simulation.