Authors: Keiji Hayashi
Affiliation: Stanford University, W.W. Hansen Experimental Physics Laboratory
We will present the global structure of the solar wind obtained with the time-dependent
three-dimensional MHD simulation using the observation data of the solar photospheric
magnetic field as the boundary values. The data we used in this study are the
synoptic maps of the photospheric magnetic field observed at WSO/Stanford and
MDI/SOHO data. By using the observational solar photospheric magnetic field
data, we can obtain the solar wind structures at the periods of the observation,
in which the interplanetary disturbances will propagate.
We will present two kinds of simulation results obtained by assuming (1) the
near-isothermal polytrope gas and (2) some empirical heating models. The MHD
code we have developed is based on the concept of the TVD-MUSCL and has some
modifications in order to deal with the wide range of the order of the solar
wind variables. We will also describe some numerical boundary treatments for
the sub-sonic/Alfvenic solar surface, which is the source of the solar wind
and plays important roles to determine the solar wind quantities in the entire
heliosphere.
The derived MHD-based solar wind parameters, density, temperature, velocity
and magnetic field, are sampled and compared with the in-situ measurements by
Ulysses spacecraft at various heliocentric distances and heliographic latitudes
and the nearby-Earth measurements by IMP8, ACE, WIND and other spacecrafts.