A 3D MHD Solar Wind Model with Pickup Protons

A. V. Usmanov, M. L. Goldstein, NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA

We compute the global three-dimensional steady-state structure of the solar wind and interplanetary magnetic field from the base of solar corona to 100 AU and compare the simulated plasma and magnetic field parameters with Voyager 1 and 2  measurements. Our tilted-dipole model of the solar corona and solar wind is appropriate for solar minimum conditions and assumes a uniform distribution of neutral hydrogen throughout the heliosphere. The inclusion of the pickup protons causes a deceleration of the solar wind and an increase in average plasma temperature with heliocentric distance. The three-dimensional character of the model allows us to study both radial and latitudinal effects. The model is consistent with the changes in the proton temperature observed by Voyager 2 as it moves to higher southern latitudes in the outer heliosphere.