Three dimensional modelling

Three-dimensional modeling of the corona and the solar wind outside the corona is analyzed. Exact solution and source surface models of coronal expansion are described, and the criteria for an acceptable model of the high- speed stream structure are outlined. Theoretical considerations for axisymmetric models of the solar wind are discussed analytically, including radial flow, magnetic pressure imbalance, meridional flow, and mass and radial magnetic fluxes in the solar equatorial plane. It is concluded that three-dimensional modeling is necessary for understanding theoretical limitations in studies confined to the equatorial plane and for gaining insight into processes occurring outside of this plane. (IAA)