HR: 14:40h
AN: SH13B-05    [Abstracts]
TI: Investigation of the PFSS and Schatten Current Sheet Interface in the WSA Model
AU: * McGregor, S L
EM: slmic@bu.edu
AF: Boston University, Department of Astronomy 725 Commonwealth Ave, Boston, MA 02215 United States
AU: Hughes, W
EM: hughes@bu.edu
AF: Boston University, Department of Astronomy 725 Commonwealth Ave, Boston, MA 02215 United States
AU: Arge, C
EM: Nick.Arge@hanscom.af.mil
AF: Air Force Research Laboratory, Space Vehicles Directorate 29 Randolf Road, Hanscom AFB, MA 01731 United States
AB: The Wang-Sheeley-Arge (WSA) solar wind model makes use of coupled Potential Field Source Surface (PFSS) and Schatten Current Sheet (SCS) models to derive the magnetic topology of the corona. Ground-based synoptic maps of the line-of-sight photospheric magnetic field are used as input to the model. The PFSS model determines the coronal field from the photosphere out to an outer boundary of 2.5 solar radii (i.e., the source surface), where, in addition, the field is traditionally set to radial. This additional constraint is imposed to account for the no longer current-free situation in the outer corona caused by the solar magnetic field frozen into the coronal plasma and then dragged out by the solar wind as it flows radially outward. Volume currents at 2.5 Rs and beyond are assumed to cancel the transverse magnetic field components. The radial magnetic field values at the source surface are then used as the input to the SCS model, which determines the magnetic field topology of the upper corona. Since the SCS model assumes, unlike the PFSS model, that there are no volume currents (except where the IMF polarity reverses), the forcing of the magnetic field to be radial at 2.5 Rs can cause discontinuities or "kinks" in the magnetic field lines at the source surface. Here we investigate the interface between the two models and suggest and test a new coupling that minimizes these field discontinuities.
DE: 7509 Corona
DE: 7511 Coronal holes
DE: 7524 Magnetic fields
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005