AGU Fall Meeting location:San Francisco, California date:11-15 December 2006
In magnetotail physics, a realistic description of magnetic reconnection would seem to require the self- consistent description of the interaction between a thin, internal current sheet and solar wind flow in an open domain, for changes in the global topology of the magnetotail and collision-less reconnection in the thin current sheet are strongly coupled. The obvious challenge in modeling such problems is the wide range of time and space scales involved. Kinetic descriptions for the thin current sheet are too expensive to extend to MHD flows, and magnetohydrodynamic (MHD) models lack the kinetics that are essential for the current sheet. Multi-scale, multi-domain methods which combine MHD and kinetic models encounter differences in basic assumptions and dependent variables between kinetics and MHD that make imposing flux matching or Marshak conditions across an interface between fluid and kinetic regions problematic. To meet these challenges, we have developed a common framework for the MHD and kinetic models. Our approach exploits the common features of implicit-moment kinetic simulations and particle-in-cell MHD, to formulate field equations that share a common form and common dependent variables for MHD and kinetic simulations. We will discuss the formulation, implementation, and potential applicability of our model. Support for this work under NSF Grant PHY-0614006 is gratefully acknowledged.