A global MHD solar wind model with WKB Alfvén waves
A. V. Usmanov and M. L.
Goldstein, NASA/Goddard Space Flight Center,
We have developed a global MHD model of the solar corona and solar wind designed to reproduce Ulysses observations during its first fast latitude transition in 1994-1995. The model includes Alfvén wave momentum and energy addition into open field regions that provides an additional acceleration for the solar wind flow. The simulation domain extends from the coronal base to 10 AU and consists of two regions with a boundary between them placed at 20 solar radii ensuring that in the outer region the flow is both supersonic and super-Alfvénic. The inner region steady-state solution is obtained for a surface dipolar magnetic field by the time relaxation method. The solution in the outer region depends only on the values at the boundary between the inner and outer regions and is constructed by forward integration along radius. The original axisymmetric model of Usmanov et al. [JGR, 105, 12675, 2000] is modified to include an inclined dipole and three-dimensional computations in the outer region. Also, solar rotation is incorporated into the present model and therefore the stream interactions are treated self-consistently. We compare the output from the model with Ulysses observations obtained during the spacecraft's first fast latitude transition in 1994-1995. We show that our model agrees with the Ulysses observations and reproduces the observed latitudinal extension of slower wind belt.